Distr.
RESTRICTED
ISED/R.85
8 May 1997
UNITED NATIONS
INDUSTRIAL DEVELOPMENT ORGANIZATION
ORIGINAL: ENGLISH
THE DEVELOPMENT AND TESTING
OF A
COCONUT CHEESE PRODUCTION TECHNOLOGY *
.
Prepared by the
F OOD P ROTEIN R ESEARCH
AND
D EVELOPMENT C ENTER**
and
DR. SUKONCHEUN SRINGAM***
*
This document has not been edited.
** Texas Engineering Experiment Station, Texas A&M University System, College Station,
Texas, United States of America, under the leadership of Dr. Khee Choon Rhee.
*** Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University,
The Kingdom of Thailand.
V .97-22942
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CONTENTS
Page
CHAPTER 1. THE DEVELOPMENT OF A COCONUT CHEESE PRODUCTION
TECHNOLOGY
vii
EXECUTIVE SUMMARY
viii
FOREWORD
xi
ABSTRACT
xii
I.
INTRODUCTION
1
II.
OBJECTIVES
1
III.
SCOPE OF WORK
2
IV.
LITERATURE REVIEW
2
IV. 1 Utilization of Coconut Milk in the Manufacture of “Soft Cheese”
IV.1.1 Fresh Soft Cheese (Cadtri Cheese)
IV.1.2 Coconut Milk and Filled Cheese Milk
IV.1.2.1 Characteristics of Cadtri Cheese
IV.1.2.2 Low-Fat “Queso de Ajo” and Fresh Soft Cheese with Starter
IV.1.2.3 Use of Coconut in Blue-Type Cheese Production
IV.1.2.4 Formulations of Coconut and Skim Milks in White
Soft Cheese Production
IV.1.2.5 Low-Fat Yogurt and Fermented Beverage from Coconut Milk
3
3
3
3
4
5
5
6
IV.2 References
6
V.
DEVELOPMENT OF CHEESELIKE PRODUCTS
7
V.l
Materials and Methods
7
V.l.l
V.1.2
V.1.3
V.1.4
V.1.5
V.1.6
V.1.7
V.1.8
7
7
8
8
8
8
9
V.1.9
V.1.10
V.1.11
V.1.12
V.1.13
Raw Materials
Profiles of Different Solubility Fractions of Coconut Proteins
Proximate Compositions
Preparation of Defatted Coconut Milk (Extraction of Coconut Protein)
Production of Coconut Protein Concentrate
Production of “Tofu-type” Product by Salt-coagulation
Production of “Tofu-type” Product by Heatcoagulation
Effects of Fat Content of Coconut Milk on Texture and Melting
Property of Tofu-type Products
Effects of pH, NaCl and CaSO4 on Formation and Hardness of
Tofu-type Products
Preparation of Cheese-like Products from Coconut Protein Concentrate
Electrophoresis
Textural Property Analyses
Melting Property Analyses
i
9
10
10
11
11
11
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(cont.)
Page
V.1.14 pH-Solubility Profiles of Coconut Proteins
V.1.15 Emulsion Stability of Coconut Protein Concentrate
12
12
Results and Discussion
12
V.2.1 Protein Content of Different Solubility Fractions
V.2.2 Electrophoresis
V.2.3 Extraction of Coconut Protein
V.2.4 Removal of Fat from Coconut Milk
V.2.5 Production of Coconut Protein Concentrate
V.2.6 Protein Extractability Profiles of Defatted Coconut Flour
and Coconut Meat
V.2.7 Emulsion Stability of Coconut Protein Concentrate (CPC)
V.2.8 Effects of pH on Emulsion Stability of CPC
V.2.9 Effects of Emulsifying Salts
V.2.10 Effects of Heat Treatment
V.2.11 Tofu-type Products Directly from Coconut Milk
V.2.12 Comparison of Salt-coagulated and Heatcoagulated Tofu-type Products
V.2.13 Effects of Fat Content of Coconut Milk on Texture and Melting Property
of Tofu-type Products
V.2.14 Effects of pH, CaSO4 and NaCl on Hardness of Coconut-tofu
V.2.15 Evaluation of Textural Properties
V.2.16 Evaluation of Melting Properties
V.2.17 Formulations and Textural Properties of Cheese-like Products
V.2.18 Textural Properties of Cheese-analogs
V.2.19 Preparation of Cheese-like Products from Wet Coconut Curd and Guar Gum
12
12
13
14
14
V.3
References
21
VI.
CONSUMER RESPONSE TESTING
22
VI.1
VI.2
VI.3
VI.4
Coconut Milk Extraction
Coconut Protein Concentrate Preparation
Production of Cheese-like Products
Production of Tofu-type Products
22
23
24
25
VII.
PROPOSED PROCESSES AND PRODUCTS
25
V.2
VIII. CONCLUSIONS AND RECOMMENDATIONS
ii
15
15
16
16
16
16
16
17
17
18
18
19
19
20
26
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OF CONTENTS
(cont.)
Page
Tables
Formulation for cheese-like product 1 for sensory testing
24
Table 19 Formulation for cheese-like product 2 for sensory testing
24
Table 20 Result of sensory test of cheese-like product 1
27
Table 21
Result of sensory test of cheese-like product 2
28
Table 22
Result of sensory test of tofu-type product
29
Table 23
Serving suggestions by panelists of test 1 and test 2
30
Table 24
Results of sensory test in four attributes of products in test 3
30
Flow diagram showing the protocol used for fractionation of coconut
proteins by solubility in different solvents
31
Figure 2
Schematic diagram for producing defatted coconut milk
32
Figure 3
Production of coconut protein concentrate utilized for producing
cheese-like products
33
Schematic diagram for producing salt-coagulated tofu-type products
from whole or defatted coconut milk
34
Schematic diagram for producing heat-coagulated tofu-type products
from whole or defatted coconut milk
35
Production of cheese-like products from coconut protein concentrate
and coconut milk
36
Figure 7
SDS-PAGE profile of coconut proteins
37
Figure 8
SDS-PAGE profile of coconut proteins
37
Figure 9
Yields of coconut protein at various NaCl concentrations
38
Table 18
Figures
Figure 1
Figure 4
Figure 5
Figure 6
Figure 10 Effects of extraction temperature on protein yield
39
Figure 11 SDS-PAGE patterns of proteins
40
Figure 12 Percent nitrogen extracted from defatted flour in water and 0.5M NaCl
at various pH’s
41
Figure 13 Percent nitrogen extracted from the coconut meat in water and 0.5M NaCl
at various pH’s
42
Figure 14 Effects of pH on emulsion stability of coconut protein concentrate
43
Figure 15 Effects of emulsifiers on emulsion stability of coconut protein concentrate
44
Figure 16
Effects of heating temperature on emulsion stability of coconut
protein concentrate
iii
45
T ABLE
OF CONTENTS
(cont.)
Page
Figures (cont.)
Figure 17 Precipitability profiles of coconut proteins at various pH’s
46
Figure 18 Effects of salt types and concentrations on the precipitability
of coconut protein
47
Figure 19 Effects of calcium salts on the precipitability of coconut proteins at
various pH’s in the presence of 0.5M NaCl
48
Figure 20 Effects of fat content of coconut milk on the yield of tofu-type product
49
Figure 21 Effects of pH on the hardness of tofu-type curds
50
Figure 22
51
Effects of CaSO4 concentration on the hardness of tofu-type curds
Figure 23 Effects of NaCl concentration on the hardness of tofu-type curds
52
Figure 24 Comparison of hardness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve
53
Figure 25 Comparison of adhesiveness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve
54
Figure 26
Comparison of fracturability among different tofu-type products and
commercial cheeses as determined by the texture profile analysis curve
55
Figure 27 Comparison of cohesiveness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve
56
Figure 28 Comparison of springiness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve
57
Figure 29 Comparison of hardness as determined by the texture profile analysis
between cheese-like products and commercial cheeses
58
Figure 30 Comparison of adhesiveness as determined by the texture profile analysis
between cheese-like products and commercial cheeses
59
Figure 31 Comparison of cohesiveness as determined by the texture profile analysis
between cheese-like products and commercial cheeses
60
Figure 32 Comparison of springiness as determined by the texture profile analysis
between cheese-like products and commercial cheeses
61
Figure 33 Schematic diagram for manufacturing cheese-like products from coconut curd
and guar gum
62
Figure 34
Hardness of coconut cheese-like product from coconut curd at various
guar gum contents
Figure 35 Cohesiveness of coconut cheese-like product from coconut curd at various
guar gum contents
Figure 36
Springiness of coconut cheese-like product from coconut curd at various
guar gum contents
Figure 37 Schematics for coconut protein concentrate preparation and yield
iv
63
64
65
66
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(cont.)
Page
Figures (cont.)
Figure 38 Schematics for tofu-type coconut curd processing and yield
Figure 39
Figure 40
67
Schematic diagram for manufacturing cheese-like products from coconut
protein curd (proposed)
68
Schematic diagram for manufacturing cheese-like products from
coconut milk (proposed)
69
Figure 41 Application of processed cheese-like product formulations to tofu-type
processing (proposed)
70
CHAPTER 2. THE TESTING OF THE DEVELOPED COCONUT
CHEESE PRODUCTION TECHNOLOGY AND
EQUIPMENT SPECIFICATION
71
INTRODUCTION
72
FINDINGS AND RECOMMENDATIONS
72
1.
Coconut protein concentrate production
72
2.
Coconut cheese-like production
76
3.
Coconut tofu-type production
76
CONFIRMATION OF COCONUT CHEESE
PRODUCTION TECHNOLOGY
77
DESIGN OF SPECIFICATIONS
77
List of equipment
84
Specification of equipment for coconut protein concentrate production
87
1.
2.
3.
4.
5.
6.
7.
8.
87
87
88
88
88
89
Spray drum washer
Coconut meat shredder
Horizontal trough ribbon mixer
Screw press
Shell and tube heat exchanger
Three-phase centrifuge
Ultrafiltration unit
Spraydryer
89
Specification of equipment for coconut cheese-like product production
1.
2.
3.
4.
Steam jacket kettle with paddle agitator
Steam jacket kettle with planetary mixer
Framingtray
Coolingtunnel
v
90
90
90
91
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(cont.)
Page
5.
6.
91
91
Cutting machine
Wrapping machine
Specifications of equipment for coconut tofu-type product production
1.
2.
3.
4.
5.
92
92
92
92
93
93
Scraped surface heat exchanger
Cooling unit
Screw decanter
Moulding and pressing machine
Wrapping machine
List of auxiliary supplies/equipment
94
CONCLUSION
95
Contacted equipment supply companies
96
References
98
vi
CHAPTER 1
THE DEVELOPMENT OF A
COCONUT CHEESE PRODUCTION TECHNOLOGY
Prepared by the
Food Protein Research and Development Center,
Texas Engineering Experiment Station
Texas A&M University System, USA
vii
EXECUTIVE SUMMARY
1.
Background
Coconut protein is of relatively good nutritional quality but its use as food has been limited,
due mainly to its extremely small amount in the nut and the difficulty of extracting and recovering it.
This study was therefore undertaken to determine if the extraction and recovery of coconut protein
can be improved and if new food products can be developed utilizing the recovered coconut protein
as one of the main ingredients.
Successful development of new coconut protein extraction and recovery techniques and new
coconut protein-based food products will bring substantial economic benefits to coconut-growing
countries by enabling them to produce not only one but two basic types of valuable products from
coconuts for food uses - the traditional product, coconut oil, and the new product, coconut protein.
Traditionally, the majority of coconut protein has been consumed in the form of coconut milk, both
full fat and defatted (or skimmed). While coconut milk has enjoyed wide acceptance among the people
in coconut-producing countries, it has not been practical to use coconut milk as a commercial food
product or ingredient because of the severe limitations inherent to all dilute liquid-type products,
i.e. extremely large volume to handle, relatively low protein concentration, and poor shelf stability
and palatability. Nevertheless, there have been some indications in published reports that coconut
protein could be used, along with coconut fat, to prepare highly acceptable and relatively inexpensive
new types of dairy-like foods.
2.
Objectives
The overall objective of this study was to develop technologies that can be used to produce
cheese-like products from coconuts. To accomplish this objective, a series of specific tasks were to
be carried out in two phases.
The first phase consisted of a detailed literature review to assess the current status of the
technology, laboratory testing of a selected number of published methods to determine if any of the
methods would merit further evaluation, and to define new production technologies for preparing
various types of dairy-like products. The second phase dealt with pilot plant operations, identification
of process equipment and market acceptance tests.
3.
Literature review
A comprehensive literature search has been conducted on cheese-like products made from
coconut milk utilizing global computer database systems which included Knowledge Index
(Agribusiness, Agricola, Cab Astracts, Food Science and Technology Abstracts and Biotechnology
Abstracts) and BRS (Patent Data, Agricultural, Biological and Environmental Sciences, Engineering
Technology and Applied Sciences).
Most of the published articles and patents dealt with the use of coconut oil as a substitute for
butterfat in the manufacture of various types of cheese-like products, such as “Cadtri”, “Kesong Puti”,
“Queso de Ajo”, blue cheese and a few different types of soft cheeses. Some of these products were
quite acceptable and coconut oil was the major source of fat. However, in all cases, skim milk powder
(mostly in the form of reconstituted skim milk) was the major source of protein, and information
regarding the use of coconut milk and/or dry coconut protein as the major source of protein for
preparation of cheese-like products was not available.
viii
4.
Experimental
In order to utilize coconut protein as the major source of protein in preparing coconut-based
cheese-like products, the investigation has been focused on two areas: extraction and recovery of
coconut protein and product development. Maximum extraction and recovery of protein was
considered the single most important critical task facing the project because of the extremely low
protein content of coconuts as opposed to the very high oil content.
A wide spectrum of known techniques was therefore examined to maximize protein extraction
and recovery. As a first step, various process conditions, such as type of salt, salt concentration, pH,
temperature, extraction time and method, were optimized to increase the extractability of the protein
from grated fresh coconut meats. These extraction studies were then followed by the development of
methods for maximum recovery of the extracted protein. It is well known that a considerable amount
of the extracted protein cannot be recovered as products by conventional protein recovery techniques.
Also, a series of experiments were conducted to optimize conditions for separation of coconut oil so
that both protein and oil can be separated and recovered simultaneously.
The product development part of the investigation concentrated on two distinctly different types
of products - tofu-type and cheese-like products. In both cases, coconut protein was the major source
of protein. As necessary, soy and milk proteins were also used to learn the tofu- and cheese-making
techniques and to compare the quality of the resulting products.
Finally, a selected number of final products were evaluated through a limited consumer
acceptance test to determine the response of the general public towards the new types of coconut
protein food products.
5.
Results
The optimum extraction of coconut protein was achieved by using 0.5-1.0 M NaCl solution at
pH 7-8 and 35-55°C. Acceptable tofu-type products were produced from coconut milk with a
maximum yield of about 50 per cent without adding other proteins. Textural properties of the final
products differed considerably depending on the manner the starting coconut milk was prepared and
the method of protein coagulation. Tofu-type products were produced from various types of coconut
milks, but the products from defatted (skimmed) coconut milk were firmer than those from full-fat
coconut milk. Calcium sulfate produced firmer products than other coagulants tested.
Cheese-like products can be produced from coconut protein concentrate, as reported in Interim
report II, but it is rather expensive to produce. Therefore, in order to reduce the amount of coconut
protein concentrate, fresh coconut milk or UF concentrated coconut milk was used as a partial source
of protein and oil along with coconut protein concentrate. Products were also made by replacing a
portion of coconut protein concentrate with various amounts of Na-caseinate or non-fat dry milk.
Cheese-like products made entirely from coconut-milk had a cream cheese texture. Cheese-like
products prepared from formulas consisting of more than 60 per cent coconut protein concentrate had
a hardness similar to sharp Cheddar. All analog cheeses displayed unique characteristics, i.e., high
adhesiveness, no fracturability and no melting properties.
Toward the end of the project, another alternative method of producing cheese-like products
was tested based on the suggestions made by the consultant. This involved the use of wet coconut
protein curd (tofu-like product) prepared from fresh defatted or concentrated coconut milk along with
hydrocolloid such as guar gum. Cheese-like products containing 6-7 per cent guar gum had a texture
similar to sharp Cheddar. All guar gum containing products displayed certain unique characteristics,
i.e., stickiness, no adhesiveness, no fracturability and high springiness.
ix
A selected number of tofu-type and cheese-like products were produced at the Department of
Food Science and Technology, Kasetsart University, Bangkok, Thailand for a limited consumer
response test. A few minor modifications were made to the formulations and processes as needed to
accommodate the local capability.
The preliminary test received mixed reactions - flavour and texture were acceptable but the
products were too salty. Once the protein extraction procedure was modified to reduce the saltiness
of the products, the response became favourable. Cheese-like products received an overall acceptance
rating of 5.1-5.6 (hedonic scale of l-9). Tofu-type products received an overall acceptance rating of
4.1, with such comments as “too bland” or “tasteless”.
6.
Conclusions and recommendations
Technologically sound processes have been developed and optimized to produce acceptable
cheese-like and tofu-type products with a wide range of protein and fat contents and texture. However,
economic merit of these processes has to be addressed more carefully due mainly to the extremely low
protein content in comparison to the extremely high fat content of coconut meats. Even under the best
conditions, only about one half of the protein present in the coconut meat can be recovered as usable
products and a very large volume of process water has to be dealt with. Because of these reasons,
economics of producing cheese-like and/or tofu-type products does not seem favourable if these
products were to be considered the major products from coconuts. If, however, these products were
to be considered byproducts (coconut fat being the major product), then the economic merit of the
newly developed processes and products becomes brighter.
It is, therefore, recommended to consider adding the coconut cheese-like and tofu-type
production lines as part of an existing coconut processing plant rather than a free-standing facility.
This approach will eliminate considerable sums of initial capital investment on equipment and
otherwise that can be shared with other coconut-processing operations.
FOREWORD
This research contract was officially signed by the United Nations Industrial Development
Organization and Texas Engineering Experiment Station on 16 July 1991; however, the actual research
began in October due to difficulties in securing a local merchant who could supply fresh coconuts on
a regular schedule.
At one time or another, the following individuals were involved in various aspects of the
research and development work.
Dr. K.C. Rhee, Principal Investigator
Dr. S.H. Kim, Research Associate
Dr. C.H. Kim, Research Associate
Ms. S. Hall, Technician II
Mr. D.H. Bae, Graduate Research Assistant
Mr. K.S. Kwon, Graduate Research Assistant
Mr. L.R. Watkins, Research Engineer
Mr. C. Vavra, Research Engineer
Student Workers
In addition, Mr. J. L. Middleton, Vice President, Olympia Cheese Company, has served as a
resource person (or consultant) at no cost to the project.
Also, Dr. S. Sringam, Associate Professor of Food Science and Technology, Kasetsart
University, Bangkok, Thailand, has served as a subcontractor for the Consumer Response Testing
portion of the project, with the assistance of her colleagues and graduate students.
xi
ABSTRACT
This project was undertaken with the aim of developing new technologies needed for producing
food products, specifically cheese-like products, utilizing coconut protein as well as oil. Efficient
extraction and recovery of coconut protein was considered the single most important factor which will
determine the outcome of this new endeavour due to the fact that the mature coconuts contain only
about 45 per cent protein. Therefore, new procedures have been developed and optimized to maximize
the extraction and recovery of the protein. This was followed by the development of procedures to
prepare new food products using the recovered coconut protein as the major ingredient for protein.
As a result, a series of acceptable tofu-type and cheese-like products were formulated as judged by
the texture analysis and the limited consumer response tests. However, even under the best conditions,
only about one half of the protein present in the coconut meat can be recovered as usable products and
a very large volume of process water has to be dealt with. Because of these reasons, economics of
producing cheese-like and/or tofu-type products does not seem favourable if the protein were to be
considered the major product from coconuts. However, if the protein were to be considered a
byproduct (coconut fat being the major product), then the economic merit of the newly developed
processes and products becomes brighter.
It is therefore recommended to consider adding the tofu-type and cheese-like product lines as
a part of the existing coconut oil extraction plant rather than a free-standing facility. This approach
will eliminate large sums of initial capital investment on equipment that can be shared with the oil
extraction process.
xii
I. INTRODUCTION
Coconut production and processing have been the predominant economic activities in rural
communities in many tropical regions of South-east Asia and the South Pacific. Traditionally,
production of coconut oil from copra (dehydrated coconut meat) has been the largest economic sector
of the coconut industry. Although copra contains proteins of reasonably good nutritional quality, its
use as food has been limited for various reasons - lipid oxidation and microbial contamination due to
the high temperature and unsanitary conditions during drying and storage. High crude fibre content
and poor protein recovery as a result of the low protein content of the nut and poor protein
extractability are the other limiting factors. Although many coconut-producing countries are in dire
need of additional food proteins, most of the potentially valuable coconut proteins have thus far been
wasted because of these problems.
This study was undertaken to determine if the recovery of coconut protein can be improved and
if new food products can be developed using the recovered protein for the purpose of expanding their
uses, minimizing waste of the potentially valuable indigenous protein source and reducing importation
of other protein ingredients into the coconut-producing countries. In most coconut-producing countries,
the current capacity for local production of cow’s milk is very small and the majority of milk and
other dairy products are manufactured from imported milk. Over the years, the importation of
extremely large quantities of milk to satisfy the consumer demands for milk and other dairy products
has been the source of genuine concern for the governments, processors and consumers alike because
the imported milk is expensive and it drains large sums of foreign exchange reserves. It is therefore
regarded as urgent and timely to develop dairy-type products from less expensive alternative sources
of indigenous raw materials, such as coconuts, to extend the locally produced milk and to develop new
dairy foods with minimum use of the imported dairy ingredients.
Among other products, the modem coconut industry is capable of producing two basic types
of valuable products from coconuts for food uses: the traditional coconut oil and the newer coconut
protein. Traditionally, the majority of coconut protein is recovered and used in the form of coconut
milk, both full fat and defatted (or skimmed). While coconut milk has enjoyed wide acceptance among
the people in coconut-producing countries, it has not been practical to use coconut milk as a
commercial food product or an ingredient because of the severe limitations inherent to all dilute liquidtype products, i.e., extremely large volume to handle, extremely low protein concentration, poor shelf
stability, and palatability. However, there have been some indications in published reports that coconut
protein could be used, along with coconut fat, to prepare highly acceptable and relatively inexpensive
new types of dairy-like foods such as custard-like products, various types of cheeses (soft, Cheddar
and blue cheeses), yogurt and drinks.
II. OBJECTIVES
The ultimate goal of this contract research was to study the feasibility of developing new
technologies that can be used to produce food products (cheese-like) from coconuts. To accomplish
this goal, the following activities were outlined in the contract:
Phase One: Literature review, raw materials studies and laboratory tests and experiments
(a)
The conduction of a comprehensive literature review worldwide using interconnected
computer systems;
(b) The evaluation of the literature review combined with laboratory tests and process
verifications;
1
(c) The outline of the work to be carried out with the aim of developing and defining a
suitable coconut “cheese” production technology;
(d) The conduction of the required laboratory experimentation and testing work;
(e) The biochemical and microbiological definition of the final products, their quality criteria
and the methods to be used for quality control activities;
(f)
The definition of the production technology for practical application in the pilot plant
production and testing phase to follow;
Phase Two: Pilot plant operations, equipment specifications and market acceptance tests
(g) Based on research report No. 1 the required experimental technical pilot equipment is to
be arranged;
(h) The experimental technical pilot operations are to be carried out and the coconut “cheese”
production technology as outlined in research report No. 2 will either be confirmed or
suitably amended and improved. As a result of this work, the following activities will be
performed;
(i)
Definition of the final coconut “cheese” production technology;
(j)
Develop process specifications for possible industrial scale operations;
(k) Production of adequate quantities of coconut “cheese” for market and consumer
acceptance tests;
(1) Conduction of market and consumer acceptance tests in selected countries/areas.
III. SCOPE OF WORK
The scope of this contract work was limited to the activities outlined in the “Objectives” above.
Also, this contract work was not intended to obtain detailed information necessary for designing a
production plant. Although much of the information generated from this project can be used for such
purposes, additional information will be needed to ensure proper design and operation of an
economically viable full-scale production plant.
IV. LITERATURE REVIEW
A comprehensive literature search has been conducted on cheese/like products made from
coconut milk utilizing global computer database systems which included Knowledge Index
(Agribusiness, Agricola, Cab Abstracts, Food Science and Technology Abstracts and Biotechnology
Abstracts) and BRS (Patent Data, Agricultural, Biological and Environmental Sciences, Engineering
Technology and Applied Sciences).
There are a number of published articles and patents on the use of coconut oil as a substitute
for butterfat in the manufacture of various types of cheese-like products; however, information
regarding the use of coconut protein as one of the major raw materials for preparation of dairy-like
products is very scarce.
2
IV.1
Utilization of Coconut Milk in the Manufacture of “Soft Cheese”
The demand for dairy products, particularly cheese varieties, is increasing rapidly in coconutproducing countries; however, not enough fresh milk is available for processing into these products.
Skimmilk powder and coconut milk, on the other hand, are more readily available than fresh milk.
The potential of water-extracted coconut milk as a less expensive substitute for butterfat in the
manufacture of fresh soft cheese manufacture was investigated (Davide et al., 1987). Also, Davide
et al. (1986, 1988) developed a fresh soft cheese spiced with garlic (Queso de Ajo), with starter and
blue-type cheese, from a blend of skimmilk powder and coconut milk. The coconut cheeses were then
compared with control cheeses similarly prepared from fresh cow’s milk.
IV.1.1 Fresh Soft Cheese (Cadtri Cheese)
A low-fat soft cheese named “Cadtri” (from the acronym for College of Agricultural Dairy
Training and Research Institute, University of Philippines at Los Banos) and a skimmilk cheese
(control) were prepared (Davide et al., 1987).
lV.1.2 Coconut Milk and Filled Cheese Milk
Coconut milk is low in protein but very rich in fat and emulsifiers (Table 1) and it is a natural
oil-in-water emulsion just like a cow’s milk; hence, both can mix readily. As a carrier of vegetable
fat to substitute butterfat, water-extracted coconut milk would be less expensive and much easier to
blend with skimmilk than coconut oil.
Table 1
Gross composition of coconut milk extract (CCM) and Cadtri cheese milk
Composition
Total solids, %
Fat, %
Total protein, %
Total ash, %
Titratable acidity, %
pH
a
b
a
Coconut milk
Cheesemilk
16.4
12.5
1.5
9.6
9.1
6.0
10.4
1.5
3.8
0.8
0.2
6.4
b
Extracted with 388 ml water per nut.
RCM/CCM blend. Blended from 13 per cent CCM and 8.7 per cent skimmilk powder.
The coconut milk was prepared by initially extracting the grated meat with 230 ml water per
nut. The resulting coconut meal was then re-extracted with 158 ml water. The two extracts were
combined and strained through a nylon cloth before mixing with reconstituted skimmilk. The
cheesemilk was formulated by blending 13 parts of the coconut milk and 87 parts of a 10 per cent
reconstituted skimmilk (Davide et al., 1987).
IV.1.2.1 Characteristics of Cadtri Cheese
Gross composition. Cadtri cheese is relatively low in fat content (7.3 per cent), but rich in
protein (13.2 per cent) and sat (1.7 per cent), and the pH (6.20) did not differ greatly from those soft
cheeses that simulate the traditional “Kesong Puti” of the Filipinos (Table 2).
Table 2
Gross composition, yield and sensory scored of Cadtri and fresh soft
a,b
cheese from skimmilk and cow’s milk
Attribute
Moisture, %
Fat, %
Total protein, %
Salts, %
pH
Yield, %
Flavour and aroma
Body and texture
Colour
a
b
Cadtri
Skim milk
Cow’s milk
72.8b
7.3b
13.2b
1.7a
6.2b
21.9b
7.2a
7.5a
7.9a
77.2b
0.0
15.8a
1.6a
6.2b
25.4a
5.9b
6.2b
7.lb
63.8b
19.1a
12.5
1.8a
6.4a
21.9b
7.5a
7.1a
6.8b
Values on the same row with different letter are significantly different at 5 per cent level.
Score of 5 means neither like nor dislike, 6 like slightly and 7 like moderately.
Sensory evaluation and consumer acceptance. Sensory evaluation and consumer acceptance data
indicated a higher preference for Cadtri cheese (Tables l-2). About 79 per cent of the consumers like
Cadtri cheese slightly to extremely, although a small percentage of consumers neither liked nor
disliked it, and still others disliked it slightly. Evidently, the addition of coconut milk gave it the
desired firm body, smooth texture, and mild coconut flavour in contrast to the skimmilk cheese which
had a tougher but brittle body, coarse texture, and astringent “skimmilk powder flavour”.
Shelf life. When refrigerated, Cadtri cheese had a shelf-life of 6-7 days. With slow drainage
of the whey storage, the cheese became slightly firmer in body, yet, no objectionable changes in
sensory qualities were observed.
IV.1.2.2 Low-Fat “Queso de Ajo” and Fresh Soft Cheese with Starter
A fresh soft cheese spiced with garlic to overcome the coconut flavour problem (Queso de Ajo)
and another cheese with lactic starter, S54 (Streptococcus cremoris and S. lactis), were developed from
a less expensive blend of skimmilk powder and coconut milk (Davide et al., 1988). Using a 2 per cent
fat standardized-cheese milk formulated from a coconut milk and a 10 per cent reconstituted skimmilk,
soft cheeses were prepared and analysed in comparison with control cheeses prepared from fresh
cow’s milk.
The 2 per cent fat experimental cheesemilk formulated from a coconut milk and a reconstituted
skimmilk was noted to be nutritionally comparable to a similarly standardized cow’s milk. The values
for total solid (11.0 per cent), fat (2.1 per cent), total protein (3.4 per cent), ash (0.7 per cent),
titratable acidity (0.9 per cent) and pH (6.2 per cent) of the 2 per cent-fat experimental cheesemilk
were not significantly different from those of the standardized cow’s milk, and yet its cost was about
21 per cent lower.
Gross composition. Both cheese varieties were found to be very nutritious and acceptable. They
were lower in fat contents (9.2-10.0 per cent) than the traditional white soft cheese or Kesong Puti
(16 to 33%), and contained 69.6-71.1 per cent moisture, 11.7-13.0 per cent total protein, and 1.61 per cent salt, which are comparable with those of the control cheese. The blend was regarded as
having a high potential as a cheesemilk for the local soft cheese industry.
4
IV.1.2.3 Use of Coconut in Blue-Type Cheese Production
Davide et al. (1986) developed a blue cheese production technology from coconut milkskimmilk powder blends.
The coconut milk was blended with 12 per cent or 15 per cent reconstituted skimmilk to obtain
a filled cheese milk containing about 3 per cent fat. Cheese milks were heated to 55°C, homogenized
at 2,000 psi and then pasteurized. The cheesemilk was mixed with 0.5 per cent lactic or 0.003 per
cent or 0.005 per cent blue mold cheese starter (Lactic starter S54 and Penicillium roqueforti spores),
and 0.02 per cent CaCl2, before it was set for 1½ hours.
The filled Blue cheese had somewhat lower fat content (24.2 per cent) than the control cow’s
milk Blue cheese (27.7 per cent). The filled Blue cheese retained more moisture than did the cow’s
milk cheese. The filled Blue cheese made from a 15 per cent reconstituted skimmilk-coconut milk
blend contained a significantly higher moisture (49.9 per cent), total protein (23.5 per cent) and yield
(13.5 per cent) but lower fat (19.8 per cent) contents than those of cow’s milk.
Apparently, the addition of more skimmilk powder to the blend caused the cheese to retain
more moisture and significantly increased its protein content. The higher pH observed in the six-weekold control and 15 per cent reconstituted skimmilk-coconut milk experimental cheese, as compared
to that of the cheese obtained from the 12 per cent reconstituted skimmilk-coconut milk blend and
control cheese of the same age, could be due to more proteolysis and lipolysis resulting from the
higher level of fungal spores (0.005 per cent) added to the cheese milk.
Based on the scores, the cow’s milk Blue cheese was liked moderately (7.15) for flavour and
aroma, while the filled Blue cheese was slightly to moderately liked (6.52). The difference could have
been due to the stronger rancid-like flavour and smell of the filled Blue cheese.
The Blue cheese from 15 per cent reconstitute skimmilk-coconut milk blend had flavour and
aroma as well as colour that were liked slightly to moderately. Its body and texture did not differ
significantly from those of the control, and was liked moderately (7.11). Increasing the skimmilk
powder from 12 per cent to 15 per cent in the cheesemilk and adding 0.005 per cent instead of
0.003 per cent fungal spores improved the sensory qualities of the filled Blue cheese.
Results showed that coconut milk is highly suitable for blending with skimmilk powder in
making a modified Blue cheese which is a potential substitute for the extremely expensive Roquefort
and other blue-type cheeses.
IV.1.2.4 Formulations of Coconut and Skim Milks in White Soft Cheese Production
Davide and Foley (1981) reported that filled cheese like Cheddar made from milk fat/coconut
oil blends did not give any desirable flavour of its own nor develop the flavour and physical attributes
of Cheddar cheese. The cheese was brittle, crumbly and appeared very coarse. Its loose moisture
increased proportionately with the concentration of coconut oil substituted. On the other hand, coconut
milk-blended soft cheese is comparable to the product made of 100 per cent fresh cow’s milk in body,
texture and general acceptability.
Sanchez and Rasco (1983a,b) conducted a study to utilize coconut milk as a cow’s milk
extender in processing white soft cheese using formulations of various combinations of coconut milk
and skim milk.
Also, the effects of the amounts of rennet on the coagulation time of cheesemilks consisting of
coconut milk plus reconstituted skim milk at different concentrations were studied.
5
Coagulation studies. Using rennet and a starter consisting of Streptococcus lactis and
S. diacetilactis, the coagulation studies of cheesemilks consisting of various combinations of coconut
milk and skim milk with added salt (3 per cent), rennet (3 per cent), starter (10 per cent) and 0.1 per
cent aqueous solution of 25 per cent calcium chloride showed that as the amount of coconut milk
increased with corresponding decrease in skim milk, the time required for curd formation increased.
The maximum amount of coconut milk in combination with skim milk that formed a curd which could
be cut was 60 per cent.
Based on the analysis, formulations having higher amounts of skim milk (10 per cent coconut
milk + 90 per cent reconstitute skimmilk to 40 per cent coconut milk + 60 per cent reconstituted
skimmilk) produced hard curds, while those with lower amounts of skim milk (70 per cent coconut
milk + 30 per cent reconstituted skimmilk to 90 per cent coconut milk + 10 per cent reconstituted
skimmilk) produced curds that were too soft to cut.
The acceptable texture of white soft cheese was obtained from treatments with 50 per cent
coconut milk + 50 per cent reconstituted skimmilk and 60 per cent coconut milk + 40 per cent
reconstituted skimmilk. Further tests indicated that soft cheeses made from these two formulations
were comparable to the soft cheeses made from 100 per cent cow’s milk in flavour, aroma, texture
and general acceptability.
IV.1.2.5 Low-Fat Yogurt and Fermented Beverage from Coconut Milk
Davide (1988) reported that a low-fat yogurt can also be prepared from coconut milk and
skimmilk blends by first homogenizing and pasteurizing it, followed by adding sugar and cultures of
S. thermophilus and L. bulgaricus.
Apart from being 98 per cent fat-free with the pleasant blending of sweetness and acidity, the
low-fat yogurt (Niyogurt) had a smooth texture with bits of pineapple, thick consistency, and desirable
flavour and aroma which the commercial brand and control yogurt made from cow’s milk exhibited.
The high fat content of coconut milk made it unsuitable for fermented beverage processing;
instead, coconut skimmilk was used (Sanchez et al., 1984). Various combinations of coconut skimmilk
and non-fat dry milk were used in preparing fermented beverages. Based on sensory evaluation, a
coconut skimmilk to non-fat dry milk ratio of 1:1 was found to be the most acceptable formulation
in terms of the sensory attributes tested and chemical compositions when compared to the control.
IV.2 References
Anon. 1985. Coconuts in white soft cheese production. Cocomunity Newsletter 15(22):8.
Bautista, R.B. 1982. Utilization of coconut milk in the manufacture of soft cheese. B.S. Thesis in
Food Technology, College of Agriculture, University of Philippines at Los Banos.
Davide, C.L. 1985. Development of new dairy foods from skim milk powder and water extracted
coconut milk. Phil. Agr. 68(4):533-549.
Davide, C.L. 1986. Cadtri cheese and niyogurt made of skimmilk and coconut milk. Research at
Los Banos 5(2):28-29.
Davide, C.L. 1988. Utilization of water-extracted coconut milk in modified dairy products processing.
Phil. Agr. Special Issue, pp. 119.
6
Davide, C.L. and J. Foley. 1981. Cheddar-type cheese with coconut oil and lipase treatment.
Phil. Agr. 64(1):67.
Davide, C.L., C.N. Peralta, I.G. Sarmago and P.A. Fuentes. 1988. New low-fat Queso de Ajo and
fresh soft cheese with starter from a skim milk-coconut milk blend. Phil. J. Coconut
Stud. 13(1):38.
Davide, C.L., C.N. Peralta, I.G. Sarmago and G.J. Pagsuberon. 1986. A new technology for blue
cheese production from coconut milk-skim milk powder blends. Phil. J. Coconut
Stud. 11(2):51-58.
Davide, C.L., C.N. Peralta, I.G. Sarmago, M.T. Yap and L.E. Sarmago. 1987. Fresh soft cheese
from skim milk powder-coconut milk blend. Phil. J. Coconut Stud. 12(1):23.
Masda, R.R. 1988. Simulated milk from coconut. An alternative to dairy milk. Food Marketing
Technol. Sept. 54-55.
Sanchez, P.C. and P.M. Rasco. 1983a. Utilization of coconut in white soft cheese production.
Research at Los Banos 2(2):13-16.
Sanchez, P.C. and P.M. Rasco. 1983b. The use of coconut in white soft cheese production. Phil. J.
Crop Sci. 8(2):93-99.
Sanchez, P.C., E.I. Dizon and A.S. Pedrezuela. 1984. Fermented beverage from coconut skim milk.
V. DEVELOPMENT OF CHEESE-LIKE PRODUCTS
V.1 Materials and Methods
V.1.1 Raw Materials
All fresh coconuts used in this development work were purchased locally as needed, and stored
in a refrigerator for a short period of time until used. A commercial partially defatted shredded
coconut was used to prepare coconut protein concentrate. A commercial desiccated coconut meal was
purchased to prepare defatted coconut flour. Coconut meal was extracted with solvent and then
desolventized at low temperature by either the conventional semi-pilot-scale hexane extraction method
or the chloroform-methanol method. The defatted meal was then dried in a fume hood and ground in
a coffee grinder to pass a 40-mesh screen. The shredded coconut, coconut meal and defatted flour
were stored at -20°C in air-tight plastic containers until used.
V.1.2 Profiles of Different Solubility Fractions of Coconut Proteins
Five different solvents, deionized distilled water, 0.5M NaCl, 70 per cent 2-propanol, 60 per
cent glacial acetic acid, and 0.1M NaOH (hereafter referred to as H2O, NaCl, IPA, HAc and NaOH,
respectively) were used in sequence to extract virtually all protein components in the coconut flour.
The protocol for this sequential extraction is outlined in Figure 1. The flour was extracted for
14-16 hours at 4°C and centrifuged at 20,000 x g for 30 minutes. Extraction with each solvent was
repeated three times.
7
All supernatants with the same solvents were combined to obtain a pool representing each
solubility fraction and assayed for protein according to the method of Bradford (1976) using bovine
serum albumin (BSA) as the protein standard. All fractions were then dialyzed against their own
solvents followed by deionized water, respectively. Dialysates were freeze-dried and the resulting
protein powders were stored in a freezer at about -20°C.
V.1.3 Proximate Compositions
Protein contents (total nitrogen x 6.25) were determined by the semi-micro Kjeldahl method
while moisture was determined by the AOAC Official Methods (AOAC, 1984). Fat contents were
determined according to the method of Folch et al. (1957).
V.1.4 Preparation of Defatted Coconut Milk (Extraction of Coconut Protein)
Coconut milk is the term used for the liquid obtained by mechanical expression of grated
coconut meat with added water, and is the first product in coconut processing. This process consists
of the steps of cracking, grating, blending, squeezing and defatting (Figure 2).
Extractabilities of coconut proteins were compared for two coconut meat-to-water ratios, 1:1
and 1:2 (w/v). Effects of sodium chloride on the extraction of coconut protein were studied at
concentrations of 0, 0.2, 0.4, 0.6, 0.8 and 1M in water.
Effects of temperature on extraction of coconut protein were studied by blending grated coconut
meats with 0.5 M sodium chloride (1:2, w/v) at temperatures of 25, 35, 45, 55 and 65°C. The percent
protein extracted was calculated as follows:
% Protein extracted =
% Protein in Meat x Weight of Meat Used
---------------------------------------% Protein in Milk x Weight of Milk
To reduce the fat content of coconut milk, the efficiency of three defatting methods was
compared: chilling, centrifugation and solvent extraction. In the chilling method, the coconut milk was
cooled at 5°C overnight. The white solidified fat layer was then separated and the protein content
determined. In the centrifugation method, coconut milk was centrifuged at 7,000 rpm, 60°C using a
Westfalia separator (Model SA7-06). The protein content of the fat layer was determined. In the
solvent extraction method, the desiccated coconut meat was defatted by soaking in hexane at 59°C for
30 minutes. This procedure was repeated two additional times at 29°C for 20 minutes to remove most
of the fat. After solvent extraction, the defatted coconut meat was desolventized and dried by blowing
cold air through it.
V.1.5 Production of Coconut Protein Concentrate
The defatted coconut milk was concentrated by an ultrafiltration process using a 10,000 or
5,000 molecular weight cut-off (MWCO) membranes (Romicon Types PM 10 and 5). After
ultrafiltration, the amount of salt and sugar in the coconut milk was then reduced to approximately
30 per cent by a diafiltration process. The concentrated coconut milk was spray-dried to produce a
coconut protein concentrate containing approximately less than 5 per cent moisture. The schematic
diagram for the process is shown in Figure 3.
V.1.6 Production of “Tofu-type” Product by Salt-coagulation
The traditional method of cheese making uses rennet to coagulate casein in cow’s milk.
However, preliminary experiments conducted in this laboratory concluded that enzymatic coagulation
8
of coconut proteins using rennet is not feasible due to the totally different characteristics of coconut
protein from cow’s milk protein in structure and physiological properties. Therefore, new procedures
were developed to precipitate or coagulate coconut proteins into semi-solid cheese-like texture.
First of all, a series of basic studies were carried out to better understand coconut proteins in
terms of their precipitation characteristics. For this study, a dry powdered coconut protein was
prepared by partially removing coconut oil from coconut milk using chilling and centrifugation
methods followed by freeze drying the defatted CM to minimize the effect of oil and thermal
denaturation of proteins on protein coagulation/precipitation. Protein precipitation studies were carried
out using 1 per cent coconut protein solution. The volume of the protein solution was brought to 40 ml
after the final pH adjustment and salt addition. The suspension was centrifuged at 4,300 x g (Sorvall
RC2-B Refrigerated Centrifuge) for 20 minutes and filtered through Whatman Filter paper No. 1 to
remove flocculent materials. The supernatant was taken for protein analysis using the Bio-Rad method
(Bradford, 1976).
Two different calcium salts (calcium chloride and calcium sulfate) were tested for their effects
on coconut protein precipitation at various concentrations ranging from 0.1 to 1.0 M. Based on the
results of these precipitation tests, a kind of tofu-type product was produced in the laboratory from
coconut milk (whole or partially defatted using the chilling method) by adjusting the pH to 3.5 and
adding 1.0 M calcium chloride in the presence of 0.5 M sodium chloride. The experimental scheme
for the process is shown in Figure 4.
V.1.7 Production of “Tofu-type” Product by Heat-coagulation
Considering the possibly high cost of calcium chloride and operational difficulties of adjusting
pH, tofu-type products were also produced by heating according to the procedure outlined in Figure 5.
Coconut milk (whole, partially defatted or completely defatted) was stirred continuously and heated
to 98°C. After boiling for 10 minutes without stirring, the heated coconut milk was removed from
the heat and allowed to cool to room temperature. After the curd was formed, the custard-like mass
was drained by squeezing through cheese cloth. The curd was pressed with slight pressure and stored
at 4°C.
V.1.8 Effects of Fat Content of Coconut Milk on Texture and Melting Property of “Tofu-type”
Products
“Tofu-type” product is produced by heating coconut milk that is an emulsion between coconut
protein and coconut fat. When denatured protein molecules aggregate to form an ordered protein
network, the process is referred to as coagulation. Although the protein plays the major role in the
coagulation, fat has important effects on texture and yields of tofu-type product, because fat is trapped
within the protein network formed by protein denaturation that can also alter the emulsion capacity
(Food Chemistry, 1985). Moreover, coconut milk contains so much fat that it is necessary to control
the fat content properly before heat treatment to enhance the textural integrity and handling of the
resulting products.
Nine types of reconstituted coconut milks were prepared by mixing the separated cream and
the defatted coconut milk at cream:defatted coconut milk ratios of 1.8:8.2 (i.e., full-fat coconut milk),
1.35:8.65, 0.9:9.1, 0.45:9.55, 0.144:9.856, 0.108:9.892, 0.072:9.928, 0.036:9.964 and 0:10
(i.e., defatted coconut milk), and they were named as coconut milk types 1 through 9, respectively.
The proximate compositions of these reconstituted coconut milk types are shown in Table 3. From
these nine types of reconstituted coconut milks, nine different tofu-type products were produced as
discussed previously and coconut milk were named as coconut curd type 1 through 9 respectively.
9
V.1.9 Effects of pH, NaCl and CaSO4 on Formation and Hardness of “Tofu-type“ Products
Aliquots (500 ml) of defatted coconut milk in citric acid buffer (ph 5) were heated until boiling.
After boiling for 3 minutes, aliquots were removed and cooled down. After draining the whey through
cheese cloth, aliquots (2 ml) of the coagulated soft curd were transferred to syringes (inside diameter,
8 mm) which were sealed at one end with cheese cloth, and then centrifuged at the speed of 1,000 rpm
for 5 minutes to remove the extra whey. The curds in the syringes were kept at 4°C for 20 hr under
500 g/cm pressure to ensure complete coagulation. Where specified, 0.01-0.05 M of CaSO4 or 0.05 M
of NaCl were added to defatted coconut milk prior to heat treatment. Also, pHs of defatted coconut
milk were adjusted to 3-10 by adding HCl or NaOH to determine the optimum pH for coagulation.
Table 3
Composition of several reconstituted coconut milk type
Milk Type
Moisture (%)
Protein (%)
Fat (%)
1
2
3
4
5
6
7
8
9
87.63
90.41
92.29
94.16
95.43
95.58
95.83
95.88
96.03
1.04
1.06
0.96
0.85
0.79
0.78
0.77
0.76
0.75
9.47
4.52
3.21
1.88
0.99
0.89
0.78
0.68
0.57
V.1.10 Preparation of Cheese-like Products from Coconut Protein Concentrate
Experimental cheese-like products (cheese analogs) were prepared using the basic formula in
Table 4 according to the modified procedure of Chen et al. (1979) who made cheese analogs from
peanut protein and oil. In order to develop suitable formulations for cheese analogs, various
combinations of ingredients were investigated based on the textural and melting properties of the
resulting products. Two experiments were conducted to test the protein sources and to adjust the levels
of protein ingredients.
In formulating and producing coconut protein-based cheese-like products, both the formulation
and processing steps used to manufacture commercial cheese analogs have been modified based on the
results obtained from the preliminary experiments. The procedure used to make the cheese analogs
is shown in Figure 6. Disodium phosphate (0.8 per cent), sodium citrate (0.8 per cent), citric acid
(0.6 per cent), and potassium sorbate (0.1 per cent) were dissolved in coconut milk, and the milk was
preheated to 60°C in a water bath. A Kitchen-Aid mixer (Model KS-A) with a water bath was used
for mixing. The coconut protein concentrate was mixed at medium slow speed within one half of the
salt solution. Mixing time was equipment dependent, but hydration was complete after an elastic and
tacky character of a homogeneous blend was noted. The rest of the salt solution was then added while
mixing. Mixing was continued until the oil and water were thoroughly emulsified in the mixture and
a smooth, homogeneous, molten processed cheese-like product was formed. The resulting cheese-like
products were poured into a cheese mold, allowed to cool, and then refrigerated 24 hours prior to
evaluation.
10
Table 4
Cheese analog preparation formula
Ingredients
Content (%)
Coconut protein concentrate
Concentrated coconut milk
Sodium citrate
Disodium phosphate
Citric acid
Potassium sorbate
47.7
50.0
0.8
0.8
0.6
0.1
V.1.11 Electrophoresis
Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was conducted using
the method of Laemmli (1970). Running gels containing 12 per cent acrylamide were prepared.
TM
Electrophoresis was performed in a 7x8x0.75 cm mini PROTEAN II dual slab cell (Bio-Rad,
Richmond, CA) at a constant voltage of 200 V. Each gel was fixed and stained with Coomassie
Blue R-250 for 3 hours in 25 per cent methanol and 10 per cent acetic acid solution and then destained
in the same 25 per cent methanol and 10 per cent acetic acid solution overnight. A high molecular
weight standard mixture (Bio-Rad) containing myosin (200,000 daltons), ß-galactosidase (116,250),
phosphorylase b (97,400 daltons), bovine serum albumin (66,200 daltons), and albumin
(45,000 daltons) was used as a molecular weight marker. For electrophoretic profiles of coconut
protein fractions, protein powders were solubilized to a final concentration of 10 mg/mL in a sample
buffer containing 2 per cent SDS, 10 per cent glycerol, and 0.05 per cent bromophenol blue in
Tris-HCl, pH 6.8, and then heated at 95°C for 3 minutes prior to loading to gel. Also, 2mercaptoethanol was added to the sample buffer to a final concentration of 5 per cent when analyzing
reduced proteins. Ten micrograms of protein were loaded to each sample well. Protein bands were
then compared in relation to the mobilities of the following marker proteins to estimate the molecular
weights: phosphorylase b (97.4 kD), BSA (66.2 kD), ovalbumin (45.0 kD), carbonic anhydrase
(31.0 kD), trypsin inhibitor (21.5 kD), and lysozyme (14.4 kD).
V.1.12 Textural Property Analyses
Textural properties of experimental tofu-type products, commercial dairy cheeses and cheeselike products were objectively determined using a Universal Instron Testing Machine Model 1011
(Bourne, 1978). All samples were cut into cubes (about 1.3 cm), and subjected to a doublecompression test with a 50 kg reversible load cell after equilibrating in an air-tight container at room
temperature for 1 hour. The samples were compressed to 75 per cent of their original height. The fullscale load of 5 or 10 kg was used. The cross head speed was 20 mm/min with a chart speed of
50 mm/min. From the force-time curve (TPA curve) of Instron data, five textural parameters were
obtained: hardness, cohesiveness, adhesive force, springiness and fracturability.
V.1.13 Melting Property Analyses
Melting properties of tofu-type products, commercial cheeses and cheese-like products were
determined by the method of Chang et al. (1976). Cheese plugs (0.6 cm thick and 1.9 cm in diameter)
were heated at 232°C for 3 minutes and subsequently assessed for melt as percent increase in
diameter.
11
V.1.14 pH-Solubility Profiles of Coconut Proteins
pH-solubility profiles of coconut proteins were determined by a modified method of Sathe and
Salunkhe (1981) on coconut meal and coconut protein concentrate. Levels of soluble nitrogen at
pH values ranging from 1.0-12.0 were determined on 2.0 per cent protein solutions of coconut meal
and coconut protein concentrate dispersed in distilled water. Solutions after pH adjustment were stirred
for 1 hour at 23°C, centrifuged at 15,000 x G for 30 minutes, and the protein contents of the
supernatants were determined by the method of Bradford (1976) with bovine serum albumin as
standard. The solubility was expressed as percentage of total protein concentration.
V.1.15 Emulsion Stability of Coconut Protein Concentrate
Emulsion stability was measured according to the method of Acton and Saffle (1970). A 0.2 per
cent protein solution was put into a vessel with solvent extracted coconut oil at a ratio of 35:65 (v/v),
to a total volume of 100 ml in order to provide a constant stirring. The samples were emulsified by
homogenization using a propeller-type mixer (Mixer Model V-7, Mixing Equipment Co.) at
16,000 rpm for 1 minute. Ten grams of the emulsion were immediately placed into a 15 x 150 mm
test tube. After standing for 30 minutes at rom temperature, 5 g of the emulsion were removed from
the bottom and the moisture content determined. The emulsion stability was calculated as follows:
100 - Mtest
Emulsion stability = ------------------------- x 100
1 0 0 - Moriginal
where Mtest = % moisture after 30 minutes and Moriginal = % moisture of the original emulsion.
V.2 Results and Discussion
V.2.1 Protein Contents of Various Solubility Fractions
Results indicate that after defatting, the protein content of coconut meal prepared from coconut
meat (endosperm) used in this study was 17.16 per cent (w/w). The sum total of protein in five
different solubility fractions amounted to 84.6 per cent of coconut meal. This suggests that sequential
extraction with five solvents did not completely release all of the protein in the coconut meal. The
contribution of individual solubility fractions to the total protein is given in Table 5. Water- and NaClsoluble fractions accounted for almost 70 per cent of the total protein.
Table 5
The contribution of different solubility fractions to the total protein
% of total protein
Fraction
22.70
46.10
2.06
12.53
1.20
13.41
Water
NaCl
Isopropyl alcohol
Glacial acetic acid
NaOH
Residue
V.2.2 Electrophoresis
Electrophoretic analysis, using SDS-PGE without ß-ME, is shown in Figure 7. Four major
polypeptides with estimated molecular weights (MW) ranging between 2l-55 kD (Figure 7, lane 1)
12
dominated the total protein composition. When ß-ME was added, the reduced proteins were resolved
into six major bands and four or more minor bands ranging between 18.0 kD and 55.0 kD (Figure 8,
lane 1). It appears from this data that the major protein in coconut is made up of at least three types
of polypeptides (MW range 21.5-55.0 kD) linked via disulfide bond(s).
Water-, NaCl- and IPA-soluble fractions contained two major coconut protein components.
HAc-soluble fraction was separated into at least two major bands with molecular weights greater than
100 kD and 55 kD; on reduction, it dissociated into more than seven peptides with molecular weights
of 20.0-55.0 kD.
V.2.3 Extraction of Coconut Protein
As shown in Table 6, the protein content of coconut meat is only about 4.4 per cent (as
compared to about 33 per cent oil). Recovering this minor component into coconut milk is therefore
the key yield-determining factor. Therefore, effects of coconut meat to water ratio, concentrations of
salts and extraction temperature on the extractability of coconut proteins were studied.
Table 6
Yield and composition of coconut meat, coconut water and coconut fibre
Yield (g)
Protein (%)
Fat (%)
Moisture (%)
Coconut meat
Coconut water
Coconut fibre
45.5
4.4
32.9
48.3
16.6
0.2
0.2
95.1
11.0
0.1
19.5
33.4
As shown in Table 7, protein extraction was enhanced by 10 per cent by increasing the coconut
meat-to-water ratio to 1:2 (2.2 per cent protein) from 1:1 (2.0 per cent protein).
Table 7
Effects of coconut meat:water ratio and salt on extractability
Composition
Coconut meat: water
(1:1, w/v)
Coconut water: water
(1:2, w/v)
Coconut fibre:0.5 M
salt soln. (1:2, w/v)
Protein (%)
Fat (%)
Moisture (%)
2.0
12.0
83.1
1.1
8.5
88.6
1.2
9.3
87.6
Protein recovery was further improved by adding sodium chloride to solubilize the salt-soluble
proteins in coconut meat. As the sodium chloride concentration increased up to 1 M, the amount of
protein in coconut milk also increased (Figure 9). However, the sodium chloride concentration of
0.5 M was chosen for use in subsequent experiments because higher concentrations of salt significantly
increased the saltiness of the milk with only a small increase in protein extraction. Combining the
effects of using higher meat to water ratio and 0.5 M salt, the extraction of coconut protein increased
by more than 20 per cent.
The amount of extracted coconut proteins increased sharply by increasing the extraction
temperature from 25 to 35°C, but the value remained relatively unchanged at extraction temperatures
higher than 35°C (Figure 10). Therefore, 35°C was chosen as the extraction temperature to produce
coconut milks for all subsequent studies. Also, this temperature can easily be maintained and
denaturation of coconut proteins will be minimum at this temperature.
13
V.2.4 Removal of Fat from Coconut Milk
Protein contents of coconut oils recovered by various defatting methods are summarized in
Table 8. As expected, the solvent extraction method was the most efficient defatting method with less
than 0.1 per cent protein in the oil as compared to 2.4 per cent protein in the chill-separated oil and
0.7 per cent protein in the centrifuge-separated oil.
Table 8
Removal of fat from coconut meat and milk by various defatting methods
Defatting methods
Amount of fat removed (%)
Protein content of fat (%)
90.0
71.7
91.0
2.4
0.7
< oil
Chilling
Centrifugation
Solvent extraction
According to the electrophoretic pattern shown in Figure 11, the molecular weights of the
extracted coconut proteins range from 13,000 to 57,000 daltons as previously reported (Chakraotry,
1985). Also, the pattern demonstrated the effectiveness of the centrifugal defatting method as exhibited
by the extremely dark coconut protein bands in the defatted milk (lane 3 in Figure 11).
V.2.5 Production of Coconut Protein Concentrate
It has already been demonstrated that certain milk-derived proteins such as nonfat dry milk and
caseinate can be used in cheese-making. However, no information is available as to whether
concentrated or isolated coconut proteins would perform similar functions in cheese-making as milk
proteins do. Therefore, production of a coconut protein concentrate (CPC) was attempted.
The data in Table 9 show that approximately 22 per cent of the protein in coconut milk was
lost to UF permeate when a 10,000 MWCO membrane was used. Also, in earlier trials, approximately
40 per cent of the protein in coconut milk was lost to permeate and fat when the 10,000 MWCO
membrane and chilling methods were used. However, these losses were reduced substantially by using
a tighter membrane (such as 5,000 MWCO) and a cream separator.
Table 9
Composition of defatted coconut milk, UF retentate, UF permeate and
coconut protein concentrate prepared by ultrafiltration method
Composition
Protein (%)
Fat (%)
Moisture (%)
Defatted
coconut milk
UF permeate
UF retentate
Coconut protein
concentrate
0.8
0.6
96.0
0.2
0.5
96.7
5.2
1.3
91.2
64.2
14.0
2.0
The full-fat milk was separated by a cream separator (Westfalia centrifuges, Westfalia
Separators Ltd.) into coconut fat and defatted milk. The fat content of this defatted. milk was 0.4 per
cent, compared to 6.0 per cent for the chill-separated milk. The defatted coconut milk was then
concentrated by an ultrafiltration process using a 5,000 MWCO membrane (Romicon Type PM 5)
instead of 10,000 MWCO. The concentrated coconut milk was spray-dried to produce a coconut
protein concentrate. Although the protein content of CPC decreased by approximately 10 per cent, the
protein yield increased from 20 per cent to 41 per cent, more than twice as much (Table 10).
14
Table 10
Compositions and yield of coconut protein concentrate prepared by different
defatting and ultrafiltration methods
Composition and yield
Protein (%)
Fat (%)
Moisture (%)
Protein yield (%)
a
b
Chilling and UFa
(10,000 MWCOb)
Cream separator and UF
(5,000 MWCO)
57.8
14.0
2.0
20.0
52.1
13.7
5.0
41.0
Ultrafiltration.
Molecular weight cut-off.
V.2.6 Protein Extractability Profiles of Defatted Coconut Flour and Coconut Meat
The nitrogen solubility profiles of defatted coconut flour and coconut meat in water and
0.1M NaCl solution at pHs from 1 to 12 are shown in Figures 12 and 13. As indicated in Figure 12,
nitrogen solubility of coconut meal in water is slightly different from that in 0.5M NaCl solution.
Although nitrogen solubility increased with increasing acidity or alkalinity, the solubility on the acid
side was rather low (with a minimum solubility at pH 1.0). The solubility increased rapidly to over
70 per cent at pH 7.0 or higher. The highest nitrogen solubility in water was attained at pH 11.0 and
the lowest at pH 4.0-6.0.
Coconut meat showed lower protein solubilities than defatted coconut flour in both water and
sodium chloride solution, but the solubility curves showed similar trends (Figure 13).
The yield of coconut protein from coconut meat as starting material is presented in Table 11.
The yield of UF concentrate was 10.5 per cent of the total solids with 8.6 per cent protein content,
accounting for 39.7 per cent of the nitrogen in the starting meat. The large loss of solids was due
mainly to the high fibre content of coconut meat. Total nitrogen loss was 56.6 per cent - 36.6 per cent
in the residue, 9.5 per cent in the fat and 4.5 per cent in the permeate. The meat residual consisted
mainly of fibre. It contained 2.5 per cent protein accounting for 36.6 per cent of the nitrogen in the
starting meat
Table 11
Distribution and yields of coconut meat solids and protein in pilot plant extractions
Yield (as % of starting meal)
Composition (%)
Starting meat
Meat residue
Fat (cream)
UF permeate
UF con.
Loss
Protein
Solid
Protein
Solid
3.8
2.5
0.9
0.1
8.6
--
59.1
39.1
48.6
3.0
10.5
--
100.0
36.6
9.5
4.5
39.7
9.7
100.0
36.8
36.3
8.6
3.1
15.5
V.2.7 Emulsion Stability of Coconut Protein Concentrate (CPC)
Stability of protein emulsion is one of the important properties for process cheese-making. The
emulsion stability is dependent on pH, heating temperature and the presence of emulsifiers. During
15
process cheese-making, often emulsification of CPC and coconut oil did not work, or the emulsion
formed broke easily. Therefore, a series of studies on the emulsion stability of CPC were conducted.
V.2.8 Effects of pH on Emulsion Stability of CPC
Emulsions were prepared from solutions of coconut protein concentrate at various pH values.
Figure 14 shows the effect of pH on the stability of the coconut protein concentrate emulsions. The
emulsion stability was the lowest as its isoelectric point region and increased at pHs above and below
this region. The emulsion stability of Na-caseinate at pH 6 was markedly higher than that of CPC.
V.2.9 Effects of Emulsifying Salts
Effects of two emulsifying salts, sodium phosphate and disodium phosphate (anhydrous) which
are used widely in the cheese industry, and control (no emulsifier) were compared (Figure 15). Tests
were conducted in triplicates at pH 5.0 at 30°C. Addition of disodium phosphate showed the highest
stability.
V.2.10 Effects of Heat Treatment
The emulsion properties of soy protein generally tend to decrease if the protein solution was
heated previously (Aoki and Nagano, 1975). Figure 16 shows the effect of heat treatment on the
stability of the CPC emulsions. The protein solution was heated for 5 minutes at selected temperatures
between 30 and 95°C. The emulsion stability decreased as the treatment temperature increased, with
the lowest value at 85°C. The highest stability was observed at 50°C (mild heat).
V.2.11 Tofu-type Products Directly from Coconut Milk
Effects of pH and added salt on coconut protein precipitation are shown in Figures 17 and 18.
As evident in Figure 17, the isoelectric point of coconut proteins is around pH 4, which agrees well
with the reported value of pH 3.9 (Peters, 1960).
As shown in Figure 18, a maximum of only about 20 per cent of coconut proteins were
precipitated by either one of these salts. However, in the presence of 0.5 M sodium chloride, addition
of 1 M calcium chloride markedly increased the protein participation, more than 80 per cent at pH 4
or below (Figure 19).
Based on these results, two kinds of tofu-type products were produced in the laboratory from
coconut milk (whole or partially defatted using the chilling method), one product by adding
1.0 M calcium chloride in the presence of 0.5 M sodium chloride at the pH of 3.5 and the other by
heating the coconut milk.
V.2.12 Comparison of Salt-coagulated and Heat-coagulated Tofu-type Products
The yields and proximate contents of two kinds of Tofu-type products (salt-coagulated and heatcoagulated) were compared in Table 12.
16
Table 12
The yields and proximate composition of two kinds of Tofu-type products
Yield, a %
Protein, %
Fat, %
Moisture, %
a
Salt-coagulated
product (defatted)
Heat-coagulated
product (defatted)
Heat-coagulated
product (full-fat)
0.6
8.0
2.1
46.4
4.3
16.4
5.0
72.0
49.7
5.0
49.5
39.9
Yield = (weight of product/weight of coconut meat used) x 100.
All attempts to produce salt-coagulated tofu-type product from whole coconut milk were not
successful because the protein did not coagulate. On the other hand, the salt coagulated product from
defatted coconut milk had very low yield, strong salt taste and very weak texture. Therefore the heatcoagulation method was chosen to produce tofu-type products. Heat-coagulated tofu-type products
prepared from whole coconut milk had higher yield and retained more flavour (sweetness and coconutlike aroma) but were much more oily than the product from the defatted coconut milks.
V.2.13 Effect of Fat Content of Coconut Milk on Texture and Melting Property of Tofu-type
Products
The proximate composition of each tofu-type product, made from the reconstituted coconut milk
types 1 through 9 as discussed previously (see Table 3), is summarized in Table 13. There was no
significant difference in fat contents between curd types 1 and 5 although the fat contents of the
corresponding reconstituted coconut milks were decreased from 9.47 per cent (milk type 1) to 0.99 per
cent (milk type 5). However, there was a significant difference in fat contents between curd types 5
and 9, although the difference in fat contents between coconut milk types 5 and 9 was not significant.
These unusual phenomena were caused by the fact that the full-fat coconut milk has too much fat to
produce a tofu-type product.
Table 13
Composition of tofu-type products made from several reconstituted coconut milks
Curd type
Moisture (%)
Protein (%)
Fat (%)
1
2
3
4
5
6
7
8
9
39.86
29.75
31.68
35.73
44.81
56.99
56.93
61.24
72.02
3.61
5.00
5.76
5.09
5.30
7.70
10.45
10.70
16.38
49.50
55.43
53.91
48.00
43.47
30.87
30.17
21.81
5.00
The effect of fat content of the reconstituted coconut milk on the yield of each tofu-type product
is shown in Figure 20. The yields were calculated as follows:
Weight of Curd (g)
Yield (=) = --------------------------------- x 100
Weight of Coconut Meat Used (g)
17
The yield of tofu-type product increased proportionally to the increase in fat content of coconut
milk. The yield of type 1 was 49.7 per cent, which means 2 kg coconut meat were needed to produce
1 kg type 1 product, while for 1 kg type 9 product, 24 kg coconut meat were needed (yield =
4.26 per cent).
V.2.14 Effects of pH, CaSO4 and NaCl on Hardness of Coconut-tofu
Coconut protein was coagulated at pH 4,5 and 6. The curd was hardest and the whey clearest
at pH 5 (Figure 21). At pHs near the pI (pH 4), protein molecules show minimal interactions with
water and net charges are sufficiently small to allow polypeptide chains to approach each other.
There was no significant change in tofu hardness until the CaSO4 concentration reached 0.03M.
The hardness increased rapidly at the concentration of 0.04M CaSO 4 and decreased until the hardness
became the same as control at 0.06M CaSO4, (Figure 22). Overall, as CaSO4 concentration increased,
the curd became harder and coarser and had the appearance of precipitates rather than coagulates. This
effect could be due to the increased syneresis and loss of whey from the curd as more bonding
occurred thus making the protein matrix denser and more compact.
In the presence of 0.05M NaCl, a soft and nonelastic curd was formed, but the curd was hardly
formed at concentrations above 0.1M (Figure 23). Therefore, the effects of NaCl on coagulation and
hardness of tofu at low concentration are attributed to charge neutralization effects; the contribution
of electrostatic interactions to the formation of coconut-tofu is apparently high. This effect relates to
the “salting out”: the ions, especially Cl, react with the charges of proteins and decrease the
electrostatic attraction between opposite charges of neighbouring molecules.
V.2.15 Evaluation of Textural Properties
Five tofu-type products (curd types 1, 2, 3, 4 and 9), from coconut milk types 1
(cream:defatted milk = 1.8:8.2), 2 (1.35:8.65), 3 (0.9:9.1), 4 (0.45:9.55) and 9 (0:10), were used
for texture evaluation. As shown in Figures 24 to 28, the product type 9 (product made from defatted
coconut milk) had the highest values of almost all textural attributes, except for adhesiveness, among
all tofu-type products. The other tofu-type products have similar properties to each other, because they
have similar compositions. It was difficult to evaluate the textural properties of curd types 1 and 4,
because they melted during compression on an Instron texture measuring machine. These products
looked just like butter rather than tofu due to very high fat contents in relation to protein contents.
Curd type 9 was as hard as sharp Cheddar cheese in texture, but it was closer to hard tofu rather than
cheese, due to its lack of adhesiveness. As fat content of coconut milk decreased, the cohesiveness
increased.
Based on the results of these studies, it was concluded that the tofu-type product made from
defatted coconut milk was the most acceptable among all tofu-type products.
V.2.16 Evaluation of Melting Properties
While most types of commercial cheese, except for cream cheese, melted in round shapes, most
tofu-type products, except for curd types 8 and 9, had transparent coconut oil separated out, but did
not shrink or melt during the tests. In fact, oil was separated from curd types 1 to 7 products even
at body temperature, but curd types 8 and 9, like cream cheese and tofu, retained the same size
without melting. These results indicated that the coconut protein network, denatured by heat treatment,
may not be able to hold oil more than twice its weight. Adding an emulsifier (disodium phosphate)
did not improve the emulsion capacity of the heat-denatured coconut protein either.
18
Overall, curd types 8 and 9 had the highest acceptability and handling properties, although the
product yields were relatively low. Curd type 8 product in particular was highly recommendable for
a commercial tofu-type product because of its higher yield and four times more fat content than curd
type 9. Moreover, curd type 8 had better texture and did not separate oil when held in hands. To
produce curd type 8, it is necessary to control the protein:fat ratio of the coconut milk to
approximately 53:47 (52.78:47.22) by defatting and reconstituting with enough added water.
V.2.17 Formulations and Textural Properties for Cheese-like Products
In order to develop suitable formulations for cheese-like products, various combinations of
ingredients were investigated based on textural and melting properties.
As reported earlier in Interim Report II, cheese-like products can be produced by using coconut
protein concentrate as the major ingredient, but it is rather expensive to produce CPC. Therefore,
production of cheese-like products was attempted by utilizing fresh coconut milk or UF concentrated
coconut milk and CPC as protein and fat sources without adding any additional fat and water. In spite
of the limited flexibility in preparing formulas, this production method was to minimize the use of
CPC. In experiment 1, cheese analogs were formulated to have about 28 per cent protein, 20 per cent
fat, and 36 per cent moisture in finished products. Five formulations were prepared by mixing
appropriate amounts of concentrated coconut milk and coconut protein concentrate, or partially
replacing the total protein in CPC with 0, 10, 20, or 30 per cent Na-caseinate or 15 per cent non-fat
dry milk (NFDM).
In experiment 2, five formulations were prepared adjusting the levels of CPC and CCM. The
amounts of ingredients used for each formulation and their compositions are shown in Table 14.
V.2.18 Textural Properties of Cheese-analogs
In experiment 1, five processed cheese analogs were produced from concentrated coconut milk
and CPC or 0, 10, 20 and 30 per cent of Na-caseinate or 15 per cent of non-fat dry milk (formulations
1, 2, 3, 4 and 5, respectively). These cheese analogs were subjected to Texture Profile Analysis to
compare their textural properties with those of commercial dairy cheeses. The commercial cheeses
were Cream, Processed (American cheese) and sharp Cheddar, which represented the creamy-, softand hard-type cheeses, respectively. Surprisingly, no pronounced difference was observed in the
hardness and adhesiveness between processed and sharp Cheddar cheeses (P < 0.05).
Table 14
Amount of protein ingredients used in the preparation of five formulations of
coconut-based cheese analogs and their composition
Cheese Analog Formulas
Ingredients (%)
Protein Concentrate
Coconut Milk
Product (%)
Protein
Fat
Moisture
6
7
8
9
10
37.6
60.0
47.6
50.0
57.6
40.0
62.0
35.6
67.0
30.6
21.4(1.0)*
26.2(1.0)
36.0( 1.5)
26.3(1.1)
23.6(0.8)
31.4(0.7)
30.9(0.7)
21.9(0.5)
25.9(1.3)
33.1(1.3)
21.5(0.9)
23.5( 1.5)
35.9(1.0)
20.7(0.5)
21.6(0.3)
* Numbers in parentheses are standard deviations.
19
Figure 29 shows that protein ingredients have significant effects on cheese analog
characteristics. The cheese analogs had higher hardness and adhesiveness and lower cohesiveness with
increasing Na-caseinate levels. The observed increases in adhesiveness were not anticipated because
an earlier report showed that increasing the amount of Na-caseinate markedly decreased adhesiveness
when working with peanut proteins (Chen et al., 1979). The strongest rubbery texture (higher
compress force) was noted at the 70:30 (coconut protein: Na-caseinate) replacement level. With
decreasing Na-caseinate, cheese-like products become softer and less rubbery. No pronounced
difference was observed in springiness except the product made with 15 per cent NFDM. As shown
in Figures 29-31, coconut cheese analogs with 0,10 and 20 per cent levels of Na-caseinate replacement
showed TPA curves similar to that of cream cheese in hardness and the 30 per cent replacement
product showed characteristics similar to those of processed and sharp Cheddar cheeses. Since 0 per
cent replacement product (containing 100 per cent coconut protein) exhibited desirable cream cheese
characteristics, i.e., the smooth and spreadable properties, the effects of adjusted levels of coconut
protein on textural properties were further investigated to determine if medium or hard-type cheese
analogs, i.e., processed or sharp Cheddar cheese, can be produced.
Five formulations (6, 7, 8, 9 and 10) were prepared with increasing levels of CPC (decreasing
levels of CCM). As shown in Table 14, these adjustments in CPC and CCM levels resulted in the
increased protein content and reduced fat and moisture contents of the resulting cheese analogs. As
shown in Figures 29-31, different levels of CPC and CCM also altered textural properties of cheese
analogs containing 100 per cent coconut protein. The obvious differences were observed in hardness
and adhesiveness. Increasing the CPC content (higher protein, lower moisture and oil) increased
hardness and adhesiveness but decreased cohesiveness of cheese analogs. Springiness was not
significantly affected by these changes in CPC levels (Figure 32). Formulations 9 and 10 brought
about increased hardness (25-35 newtons), which fell within the hardness range observed for sharp
Cheddar (hard-type cheese) but they also brought about strong adhesiveness. However, one of the
desirable characteristics of dairy cheeses is their low adhesiveness.
All analogs displayed unique characteristics, higher adhesiveness, no fracturability and no
melting properties. All commercial cheeses melted in round shapes but none of the coconut cheese
analogs melt well. These differences in textural properties are due largely to the differences in
molecular structure, size and composition between coconut and milk proteins, because such protein
molecular properties would influence the characteristics of the resulting gels or curds.
V.2.19 Preparation of Cheese-like Products from Wet Coconut Curd and Guar Gum
The cheese-like products discussed thus far were produced by using coconut protein concentrate
as the major protein source, but the cost of preparing coconut protein concentrate is rather expensive.
Therefore, an alternative method of producing cheese-like products was examined by utilizing wet
coconut protein curd prepared from fresh or concentrated coconut milk and hydrocolloid (guar gum).
Based on the results obtained from preliminary experiments, both the formula and process used
to prepare commercial cheese analogs were modified in formulating and producing coconut curd and
guar gum-based cheese-like products. The procedure used to make cheese-like products is shown in
Figure 33.
Defatted coconut milk was obtained according to the process discussed earlier except that a
coconut meat to extraction solvent ratio of 1: 1 (w/v) was used. The separated coconut fat was stored
under refrigeration until used. The partially defatted coconut milk was heated at 95°C for 15 minutes
while stirring slowly, and then allowed to cool to room temperature. The wet curd formed was
recovered by filtering the milk through cheese cloth. The wet curd and guar gum mixed vigorously
at 60-70°C for 3 minutes in a Kitchen Aid Mixer with a water bath. Coconut fat, emulsifier and other
additives were added and mixed thoroughly until oil and water were completely emulsified and a
20
smooth, homogeneous, molten cheese-like product was formed. The cheese analog was then poured
into a cheese mold and refrigerated before evaluation.
All experimental products were produced according to the basic formula shown in Table 15.
Five different levels of guar gum were investigated based on the textural properties of the resulting
products.
Five processed cheese-like products were produced from wet coconut curd and five levels of
guar gum, 3.0, 4.0, 5.0, 6.0 and 7.0 per cent (formulations 1, 2, 3, 4 and 5, respectively). The
addition of 6 per cent gum resulted in a product with hardness of 25-30 newtons, which is comparable
to that of commercial sharp Cheddar (Figure 34). With increasing levels of guar gum, cohesiveness
of products decreased, and formulations 4 and 5 (6 and 7 per cent gums, respectively) exhibited
cohesiveness almost identical to commercial processed type and sharp Cheddar cheeses (Figure 35).
Springiness of products decreased with increasing levels of gum (Figure 36).
Table 15
Cheese-like product preparation formula from wet coconut curd and guar gum
Ingredient
Content (%)
Coconut curd
Guar gum
Coconut fat
Phosphate
Sodium citrate
Potassium sorbate
87.0
3.0-7.0
8.0
0.7
0.8
0.1
All coconut curd and guar gum-based products displayed certain unique characteristics, such
as stickiness, no adhesiveness, no fracturability and high springiness. Based on the textural property
data, the formulation with 6 or 7 per cent guar gum can be used to produce products with better
texture, less stickiness and more rubbery.
V.3 References
Acton, J.C. and Saffle, R.L. 1970. Stability of oil-in-water emulsions. 1. Effects of surface tension,
level of oil, viscosity and type of meat protein. J. Food Sci. 35:852.
Ahmed, E.S. and Ali, T. 1986. Textural quality of peanut butter as influenced by peanut seed and oil
contents. Peanut Sci. 13:18.
AOAC. 1984. “Official Methods of Analysis”. 14th ed. Association of Official Analytical Chemists,
Washington, DC.
Aokim H, and Nagano, H. 1975. Studies on emulsifying properties of soybean proteins. J. Jap. Soc.
Food Sci. Technol. 22:230.
Bourne, M.C. 1978. Texture profile analysis. Food Technol. 32(7):62.
Bradford, M. 1976. A rapid and sensitive method for the quantitation of microgram quantities of
protein utilizing the principle of protein-dye binding. Anal. Biochem. 72:248.
Chakraborty, P. 1985. Functional properties of coconut protein isolate obtained by ultrafiltration.
J. Food. Sci. 22:248.
21
Chang, P.K. 1976. Partially delactosed whey used as NFDM replacement in processed cheese food
offers economic advantages. Food Prod. Dev. 10(6):51.
Chen, S.L., P.J. Wan, E.W. Lusas and K.C. Rhee, 1979. Utilization of peanut protein and oil in
cheese analogs. Food Technol. 33(7):88.
Dulay, T.A. 1980. Laboratory Manual in Dairy Science 135. Univ. Phils. Los Banos, College,
Laguna.
Fennema, O.R. 1985. “Food Chemistry”. 2nd ed. p. 282-294. Marcel Dekker, Inc. New York.
Folch, J., Lees, M., and Stanley, G.H.S. 1957. A simple method for the isolation and purification
of total lipids animal tissues. J. Biol. Chem. 226:497.
Kuhn, P.R. and Foegeding, E.A. 1991. Mineral salt effects on whey protein gelation. Am. Chem.
Soc. 39:1013.
Laemmli, U.K. 1970. Cleavage of structural protein during the assembly of the head of bacteriophage T4. Nature 227:680.
Peters, F.E. 1960. Preparation of amino acid composition of selected seed protein fractions, pp. 20.
Ph.D. Dissertation, Purdue University, Lafayette, IN.
Sun, N. and Breene, W.M. 1991. Calcium sulfate concentration influence on yield and quality of tofu
from five soybean varieties. J. Food Sci. 56:1604.
Torikata, Y., Ishihara, J. and Yano, T. 1987. Protein coagulation through reversible and irreversible
bindings of calcium. Agric. Biol. Chem. 51:707.
Utsumi, S. and Kinsella, J. E. 1986. Forces involved in soy protein gelation: Effects of various
reagents on the formation, hardness and solubility of heat-induced gels made from 7S, 11S and
soy isolate. J. Food Sci. 50:1278.
VI. CONSUMER RESPONSE TESTING
The consumer response testing was subcontracted to the Department of Food Science and
Technology, Kasetsart University, Bangkok, Thailand, between 1 June and 30 September 1993. The
project leader of the test was Dr. S. Sringam, Associate Professor, and she was assisted by her
colleagues and graduate students in the department. The test was carried out on both tofu-type and
cheese-like products. The test site was visited by Dr. K.C. Rhee, the principal investigator, in early
June for a period of one week to train Dr. Sringam and her crew on how to prepare coconut protein
ingredients using the ultrafiltration membrane system and the text products. The following is the report
from Dr. Sringam on the preparation of coconut milk, coconut protein concentrate and tofu-type and
cheese-like products as well as the consumer acceptance test results.
VI.1 Coconut Milk Extraction
The coconut milk extraction procedure, which was developed for the project, was slightly
modified according to the facilities available at the test site (Table 16). Preliminary testings showed
that the original extraction method yielded too low solid content in the UF retentate to spray drying
and the resulting coconut protein concentrate was judged too salty by the local panelists.
22
A two-step extraction was used with reduced salt concentration from 2 per cent to 1 per cent.
For 25 kg shredded coconut meat, 50 kg of water and 500 g of salt were used. Percent extractable
protein increased from 77 per cent to 80 per cent, and the oil from 71 per cent to 76 per cent. The
yields were still low, and they were believed to be caused by the absence of the grinding step of
coconut meats with salt solution, resulting in too large coconut meat particles for efficient extraction.
Table 16
Comparison of two procedures of coconut milk extraction
Original (a)
Coconut meat
Amount/Residue (kg)
Moisture (%)
Protein (%)
Oil (%)
Extractable protein (%)
Extractable oil (%)
(a) Original procedure:
(b) Modified procedure:
25.00
54.24
3.16
27.23
---
Modified(b)
7.74
47.80
2.37
25.44
76.78
71.08
7.00
45.06
2.29
23.32
79.75
76.02
Shredded coconut meat (25 kg) was mixed for 10 minutes with 2 per
cent NaCl solution (50 kg) 45°C before pressing.
Shredded coconut meat (25 kg) was pressed with water (2.5 kg), the
residue was mixed for 10 minutes with 1 per cent NaCl solution
(35 kg), 45°C before pressing.
VI.2 Coconut Protein Concentrate Preparation
The coconut protein concentrate (CPC) from 1 per cent salt solution extraction was still too
salty (8.5 per cent salt). Therefore, CPC was prepared without salt. Coconut protein was then
precipitated with acid at pH 4.5. The coconut milk was prepared by, pressing 25 kg of shredded
coconut meat with 2.5 kg of water, and made up to 30 liters before defatting (Figure 37). The defatted
milk was adjusted to pH 4.5 with HCl and kept overnight at 5°C. Supernatant was removed, water
added, pH adjusted to 6.0 with NaOH and the final volume adjusted to 6.5 litres. The yield of the acid
precipitated CPC was about 80 per cent of the UF processed CPC. This new CPC contained about
3 per cent salt (Table 17).
Table 17
Chemical composition of raw materials
Moisture (%)
Protein (%)
Oil (%)
Sodium chloride (%)
CPC I:
CPC II:
CCM I:
CCM II:
CMP:
CPC I
CPC II
CCM I
CCM II
CMP
4.22
48.22
25.62
8.45
4.36
45.29
30.35
2.69
57.53
3.40
34.27
--
76.61
1.69
17.21
--
4.16
3.41
34.35
--
Coconut protein concentrate prepared by ultrafiltration method.
Coconut protein concentrate prepared by acid precipitation method.
Concentrated coconut cream prepared by pressing shredded coconut milk without
water added.
Concentrated coconut cream as UHT homogenized coconut milk.
Coconut milk powder (contains about 51 per cent dextrin).
23
VI.3 Production of Cheese-like Products
The two CPCs were mixed 1:1 for the first sensory test (Tables 18 and 19). The concentrated
coconut milk was replaced with coconut milk pressed without added water because the amount needed
was too small to use the ultrafiltration method. The preparation procedure was followed except that
manual mixing was done over a hot water bath. The hedonic scale of l-9 was used. The scores for
the three products were low (3.96, 3.71 and 4.1, respectively) due mainly to the saltiness of the
products.
Table 18
Formulation for cheese-like product 1 for sensory testing
Coconut protein concentrate I
Coconut protein concentrate II
Concentrated coconut milk I
Concentrated coconut milk II
Coconut milk powder
Citric acid
Disodium phosphate
Sodium citrate
Sugar
Flavour
Test 1
Test 2
Test 3*
24.33
24.33
49.00
--0.60
0.85
0.80
-(0.30)
-53.05
-45.42
---
-47.93
-36.68
11.96
-0.78
0.74
1.83
(0.30)
0.78
0.74
-(0.30)
Note: When not all liquid portions in the original formula were used, each percentage was
recalculated.
* Composition (by calculation): Moisture 30.69%, protein 22.73%, oil 24.97%.
Table 19
Formulation for cheese-like product 2 for sensory testing
Coconut protein concentrate I
Coconut protein concentrate II
Concentrated coconut milk I
Concentrated coconut milk II
Coconut milk powder
Citric acid
Disodium phosphate
Sodium citrate
Sugar
Flavour
Test 1
Test 2
Test 3*
30.83
30.83
36.00
---
-65.83
-32.67
--0.78
0.74
-(0.30)
-58.32
-23.65
14.56
-0.57
0.53
23.6
(0.30)
0.60
0.85
0.80
-(0.30)
Note: When not all liquid portions in the original formula were used, each percentage was
recalculated.
* Composition (by calculation): Moisture 21.27%, protein 27.25%, oil 26.77%.
24
For the second test, the acid precipitated CPC was then used. The liquid portion of the formula
was reduced to 85 per cent to improve the consistency and texture. Also, UHT homogenized coconut
milk was used in place of the concentrated coconut milk to improve the oily appearance and strong
coconut smell. The scores were improved to 4.21 and 4.45 (for products 1 and 3, respectively)
(Table 20).
For the third sensory test, sugar was added to the formula based on the suggestions from a
large number of panelists. Coconut milk powder was added to adjust the solid content of the
concentrated coconut milk. The texture of the cheese-like product 3 became too soft to cut at room
temperature. However, the scores improved to 5.06 and 5.61 (Table 21).
VI.4 Production of Tofu-type Products
Tofu-type product was prepared by heat precipitation of defatted coconut milk at pH 5.0
(Figure 38). Sodium chloride was added just before removing from the heat. The adjustment of salt
from 1.7 to 1.9 per cent (based on the defatted milk) in the first and second tests did not significantly
change the score. The first one was too milky and the second one was too salty. Salt content of
1.8 per cent was then used in the third test. The score improved a little to 4.10, showing that the salty
taste was not the major factor (Table 22).
Based on the panelists’ suggestions (Table 23), an additional test was conducted. Tofu-type
product was cut into dices and served with syrup and ice. The dices were soft, but the score improved
to 4.6. The test results on four typical sensory attributes of cheese-like and tofu-type products are
summarized in Table 24.
VII. PROPOSED PROCESSES AND PRODUCTS
Based on the experimental results thus far obtained, it is proposed that the following options
are to be considered to commercially produce both tofu-type and cheese-like products using several
different types of coconut milk and other additives:
1.
Cheese-like products from defatted coconut milk or concentrated coconut milk prepared by
ultrafiltration (Figure 39). The wet curds prepared by heat or salt precipitation become tofu-like
products when the liquid is drained and put in a mold.
2.
Aged cheese-like products from partially defatted coconut milk or concentrated coconut milk
by ultrafiltration using the combined heat and salt coagulation method to increase the product
yield (Figure 40).
3.
Modified cheese-like products from partially defatted coconut milk using a processed cheesemaking procedure (Figure 41).
According to the equipment manufacturers, as well as our consultant, process equipment is
readily available for a wide range of production capacities for both tofu- and cheese-type products
from soybeans (tofu-type) and cow’s milk (cheese-like), respectively; none of them were able or
willing to make a recommendation for processing of coconut milk into either one of the products
because their equipment has not been tested for such purposes. They were however confident to come
up with a production plant if they can make a few trial runs using their equipment to learn biomass
and rheological characteristics of coconut milk and its derivatives.
25
VIII. CONCLUSIONS AND RECOMMENDATIONS
Technologically sound processes have been developed and optimized to produce acceptable
cheese-like and tofu-type products with a wide range of protein and fat contents and textures. These
products are ready for industrial production.
However, the economic merit of these processes has to be carefully addressed, mainly due to
the low protein content in comparison to the high fat content of coconut meats. Even under the best
conditions only about one half of the protein present in the coconut meat can be recovered as usable
products.
For this reason the economics of producing cheese-like and tofu-type products from coconuts
on an industrial scale do not seem very favourable if these products were to be considered the only
major products.
It is therefore recommended that relevant production lines for the production of cheese-like and
tofu-type products be added to or combined with other coconut-processing facilities, such as coconut
cream production plants (most suitable) and even coconut oil extraction plants (with added copra
production lines using fresh coconuts as raw material) or desiccated coconut production factories. In
this context the economic merit of the newly developed processes becomes much brighter. Investors
may wish to consider the production of coconut cheese-like and/or tofu-type products in the small and
medium scale for local market demands.
26
Table 20
Result of sensory test of cheese-like product 1
Test 1
Test 2
Test 3
Number of panelists
49
66
80
Hedonic scale
3.98
4.21
5.06
Sensory attribute
Odour
Strong
Rancid
Strange
None-little
Fair
Pleasant
Number of Judgements for given score (%)*
(14.28)
(12.24)
( 2.04)
( 4.08)
( 4.08)
( 2.04)
2 ( 3.03)
7 (10.61)
--
Flavour
Very salty
Slightly salty
Flavourless
Not sweet
Sour
Too rich
Strange
Poor
Fair
Good
29 (59.18)
4 ( 8.16)
--1 ( 2.04)
5 (10.20)
--1 ( 2.04)
2 ( 4.08)
25 (37.88)
15 (22.73)
-2 ( 3.03)
1 ( 1.51)
1 ( 1.51)
2 ( 3.03)
2 ( 3.03)
1 ( 1.51)
4 ( 6.06)
Texture
Soft, mushy
Hard, dry
Sticky
Poor
Good
3 ( 6.12)
-2 ( 4.08)
-3 ( 6.12)
4 ( 6.06)
---3 ( 3.03)
7
6
1
2
2
1
4 ( 6.06)
-2 ( 3.03)
* Percentage based on total number of panelists.
27
6 ( 7.50)
3 ( 3.75)
-3 ( 3.75)
5 ( 6.25)
20 (25.00)
28
13
1
2
1
2
3
(32.50)
(16.25)
( 1.25)
( 2.50)
( 1.25)
( 2.50)
( 3.75)
-4 ( 5.00)
4 ( 5.00)
8 (10.00)
-9 (11.25)
1 ( 1.25)
6 ( 7.50)
Table 21
Result of sensory test of cheese-like product 2
Test 1
Test 2
Test 3
Number of panelists
49
66
80
Hedonic scale
4.10
4.45
5.61
Number of Judgements for given score (%)*
Sensory attribute
Odour
Strong
Rancid
Strange
None-little
Fair
Pleasant
Flavour
Very salty
Slightly salty
Flavourless
Not sweet
Sour
Too rich
Strange
Poor
Fair
Good
Texture
Soft, mushy
Hard, dry
Sticky
Poor
Good
10 (20.41)
2 ( 4.08)
---2 ( 4.08)
1
1
4
1
1.51)
1.51)
8.06)
1.51)
-2 ( 3.03)
30 (61.22)
5 (10.20)
-2
2
3
1
(
(
(
(
4.08)
4.08)
6.12)
2.04)
--
1 ( 2.04)
2 ( 4.08)
3 ( 6.12)
2 ( 4.08)
4 ( 8.16)
-3 ( 6.12)
(
(
(
(
26 (17.16)
14 (21.21)
-4 ( 6.06)
3 ( 4.54)
6 ( 9.09)
3 ( 4.54)
3 ( 4.54)
6 ( 9.09)
1 ( 1.51)
(16.25)
(18.75)
( 2.50)
( 2.50)
( 1.25)
( 3.75)
( 2.50)
-12 (15.00)
10 (12.50)
---
1 ( 1.25)
-14 (17.50)
3 ( 3.75)
6 ( 7.50)
16 (24.24)
1 ( 1.51)
1 ( 1.51)
* Percentage based on total number of panelists.
28
4 ( 5.00)
2 ( 3.03)
-4 (5.00)
5 ( 6.25)
13 (16.25)
13
15
2
2
1
3
2
Table 22
Result of sensory test of tofu-type product
Test 1
Test 2
Test 3
Test 4
Nmber of panelists
49
66
80
30
Hedonic scale
3.71
3.79
4.10
4.60
Sensory attribute
Odour
Strong
Rancid
Strange
None-little
Fair
Pleasant
Flavour
Very salty
Slightly salty
Flavourless
Not sweet
Sour
Too rich
Strange
Poor
Fair
Good
Texture
Soft, mushy
Hard, dry
Sticky
Poor
Good
Number of Judgements for given score (%)*
2 ( 4.08)
---1 ( 2.04)
2 ( 4.08)
-1 ( 1.51)
-2 ( 3.03)
---
---22 (27.50)
-4 ( 5.00)
---2 ( 6.08)
1 ( 3.33)
3 (10.00)
2 ( 6.67)
8 (26.67)
---
( 2.04)
(16.33)
(36.73)
( 6.12)
( 2.04)
( 2.04)
--5 (10.20)
18
7
15
1
2
8
(27.27)
(10.61)
(22.73)
( 1.51)
( 4.08)
(12.12)
-5 ( 7.57)
3 ( 4.54)
8 (10.00)
6 ( 7.50)
34 (42.50)
2 ( 2.50)
-1 ( 1.25)
-4 ( 5.00)
3 ( 3.75)
1 ( 3.33)
5 (16.67)
2 ( 6.67)
3 (10.00)
1 ( 3.33)
11 (22.45)
-5 (10.20)
-1 ( 2.04)
6 ( 9.09)
1 ( 1.51)
15 (22.73)
7 (10.61)
--
6 (10.00)
3 ( 3.75)
33 (41.25)
2 ( 2.50)
1 ( 1.25)
7 (23.33)
1 ( 3.33)
24 (80.00)
---
1
8
18
3
1
1
* Percentage based on total number of panelists.
29
Table 23
Serving suggestions by panelists of test 1 and test 2
Number of Suggestion (%)*
Serving
Cheese-like 1
Cheese-like 3
Tofu-type
3 ( 2.73)
12 (10.34)
13 (12.74)
With bread
44 (40.00)
37 (31.90)
15 (14.71)
With cracker
45 (40.91)
49 (42.24)
20 (19.61)
2 ( 1.82)
5 ( 4.31)
7 ( 6.86)
As food ingredient
16 (14.54)
13 (11.21)
47 (46.08)
Total
110 (100)
116 (100)
102 (100)
Alone
With fruit
* Percentage based on total suggestions of each product.
Table 24
Results of sensory test on four attributes of products in test 3
Hedonic score
Attribute
Odour
Flavour
Texture
Overall acceptance
Cheese-like 1
Cheese-like 3
Tofu-type
6.21
4.56
5.61
5.06
6.16
5.05
5.80
5.61
4.45
3.85
3.93
4.10
30
DEFATTED COCONUT MEAL
2O:1 (v:w, solvent-to-meal ratio) with deionized water
Centrifuge at 20,000 rpm, 30 min 4°C
WATER-SOLUBLE
FRACTION
PELLET
20:1 (v:W) 0.5M NaCI
NaCI-SOLUBLE
FRACTION
20:1 (v:w) 70% IPA
IPA-SOLUBLE
FRACTION
PELLET
PELLET
20:1 (v:w) water rinse
Discard
PELLET
20:1 (v:w) 60% HAc
HAc-SOLUBLE
FRACTION
PELLET
20:1 (v:w) water rinse
Discard
PELLET
20:1 (v:w) 0.1M NaOH
NaOH-SOLUBLE
FRACTION
PELLET
Figure 1.
Flow diagram showing the protocol used for fractionation of coconut proteins by solubility
in different solvents.
COCONUT
Crack and grate
COCONUT SHELL & WATER
COCONUT MEAT
Grind with 0.5M NaCI solution at the solution temperature
of 35-45°C for 4 min. (twice amount(wt) of coconut meat)
Squeeze through cheese cloth
COCONUT FIBER
COCONUT MILK
Heat up to 50°C
Defat with cream separator
COCONUT FAT
DEFATTED COCONUT MILK
Figure 2. Shematic diagram for producing defatted coconut milk.
COCONUT
Crack & grate
COCONUT MEAT & NaCl SOLUTION
Blend & squeeze
Residue
FULL FAT COCONUT MILK
Separate fat using cream separator
Fat
DEFATTED MILK
Ultrafiltrate
Permeate
RETENTATE
Spray-dry
COCONUT PROTEIN CONCENTRATE
Figure 3. Production of coconut protein concentrate utilized for producing cheese-like products
COCONUT MILK / DEFATTED COCONUT MILK
Add salt
Adjust pH 3.5
COCONUT PROTEIN CURD
Drain whey
Press
TOFU-TYPE PRODUCT (Salt-coagulated)
Figure 4. Schematic diagram for producing salt-coagulated tofu-typeproducts from whole or
defatted coconut milk.
WHOLE or DEFATTED COCONUT MILK
Stir slowly and heating up to 98°C
Remain the temperature for 10 min without stirring
Cool with cold water
COCONUT PROTEIN CURD
Drain whey through cheese cloth
Squeeze the curd through cheese cloth
Press the curd covered with cheese cloth in a mold and refrigerating at
5°C overnight
TOFU-TYPE CURD
Figure 5. Schematic diagram for producing heat-coagulated tofu-type products from whole or
defatted coconut milk.
COCONUT PROTEIN CONCENTRATE (50%)
A salt solution of disodium phosphate,
citric acid, sodium citrate and potassium
sorbate dissolved in coconut milk (50%)
Mix for 2 min
A salt solution (30%) & a coconut
proteinconcentrate (50%)
Mix
A salt solution (20%)
Mix
EMULSION
Mold
CHEESE-LIKE PRODUCT
Figure 6. Production of cheese-like products from coconut protein concentrate and coconut milk.
Figure 7. SDS-PAGE profiles of coconut proteins in
(1) water-soluble, (2) NaCI-soluble, (3) IPAsoluble, (4) HAc-soluble, (5) NaOH-soluble,
(6) residue fractions from the meal in the
absence of 2-mercaptoethanol. “S” is a
molecular weight standard.
Figure 8. SDS-PAGE profiles of coconut proteins in
(1) water-soluble, (2) NaCI-soluble, (3) IPAsoluble, (4) HAc-soluble, (5) NaOH-soluble,
(6) residue fractions from the meal in the
presence of 2-mercaptoethanol. “S” is a
molecular weight standard.
100
90 —
80 —
70
0
l
l
l
l
0.2
0.4
0.6
0.8
NaCl concentration (M)
Figure 9. Yields of coconut protein at various NaCl concentrations.
1
70
60 —
50 —
40 —
30
20
l
30
l
I
50
40
Temperature (°C)
Figure 10. Effects of extraction temperature on protein yield.
I
60
70
97.4 kD
66.2 kD
45.0 kD
31.0 kD
21.5 kD
14.4 kD
1
2
3
4
5
Figure 11. SDS-PAGE patterns of proteins in (1) coconut meat, (2) full-fat
coconut milk, (3) centrifugally defatted coconut milk, (4) tofutype product, and (5) molecular weight standards.
100
80 —
60 —
40 —
20 —
0
0
l
l
l
2
4
6
l
l
l
8
10
12
pH
Figure 12. Percent nitrogen extracted from defatted flour in water and 0.5M NaCl at
various pH’s.
14
100
80
—
60
—
40
—
20
—
0
0
l
l
l
l
l
l
2
4
6
8
10
12
14
pH
Figure 13. Percent nitrogen extracted from the coconut meat in water and 0.5M NaCl at
various pH’s.
50
40 —
30 —
20 —
10 —
0
1
l
l
l
l
3
5
7
9
pH
Figure 14. Effects of pH on emulsion stability of coconut protein concentrate,
11
12
8
4
0
Na-pyrophosphate
Disodium phosphate
Control
Emulsifier
Figure 15. Effects of emulsifiers on emulsion stability of coconut protein concentate.
40
30 —
20 —
10 —
0
20
l
l
40
60
80
100
Heating temperature (°C)
Figure 16. Effects of heating temperature on emulsion stability of coconut protein concentrate,
100
80 —
60 —
40 —
20 —
0
0
l
l
l
l
l
l
2
4
6
8
10
12
pH
Figure 17. Precipitability profiles of coconut proteins at various pH’s.
20
15 —
10 —
5 —
0
0
l
0.2
l
0.4
l
0.6
l
0.8
l
1
Concentration (M)
Figure 18. Effects of salt types and concentrations on the precipitability of coconut protein,
100
80 —
60 —
40 —
20 —
0
0
2
4
6
8
10
pH
Figure 19. Effects of calcium salts on the precipitability of coconut proteins at various pH’s
in the presence of 0.5M-NaCI.
60
50 —
40 —
30 —
20 —
10 —
0
0
l
l
l
l
2
4
6
8
Fat content of coconut milk (%)
Figure 20. Effects of fat content of coconut milk on the yield of tofu-type product.
10
2.5
2 —
1.5 —
1 —
0.5 —
0 •
3
4
5
7
6
pH
Figure 21. Effects of pH on the hardness of tofu-type curds.
8
9
10
10
8 —
6 —
4 —
2
•
0
0
0.01
0.02
0.03
0.04
Concentration of CaSO4
0.05
Figure 22. Effects of CaSO4 concentration on the hardness of tofu-type curds.
0.06
2.5
2
1.5 —
1 —
0.5 —
0
l
0
0.1
l
0.2
l
0.3
Concentration (M)
l
0.4
Figure 23. Effects of NaCl concentration on the hardness of tofu-type curds.
0.5
6
5
4
3
2
1
0
Figure 24. Comparison of hardness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve.
1.6
1.2
0.8
0.4
0
Figure 25. Comparison of adhesiveness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve.
1.2
0.8
0.4
0
Figure 26. Comparison of fracturability among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve.
50
40
30
20
10
0
Figure 27. Comparison of cohesiveness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve.
8
6
4
2
0
Figure 28. Comparison of springiness among different tofu-type products and commercial
cheeses as determined by the texture profile analysis curve.
40
30
20
10
0
1
2
3
4
5
Commercial cheeses
6
7
8
Figure 29. Comparison of hardness as determined by the Texture Profile Analysis between cheese-like
products and commercial cheeses: 1 to 5 -- cheese-like products containing 0%(1),10%(2),
20%(3), 30%(4) Na-caseinate, and 15%(5) non-fat dry milk. Commercial cheeses from left
to right -- Cream, Processed, and Sharp Cheddar. 6 to 10 -- cheese-like product containing
different levels of coconut protein ingredients. Data with a common letter do not differ
significantly (P> 0.05)
12
9
6
3
0
1
2
3
4
5
Commercial cheeses
6
7
8
9
10
Figure 30. Comparison of adhesiveness as determined by the Texture Profile Analysis between
cheese-like products and commercial cheeses: 1 to 5 -- cheese-like products containing
0%(1), 10%(2), 20%(3), 30%(4) Na-caseinate, and 15%(5) non-fat dry milk. Commercial
cheeses from left to right -- Cream, Processed, and Sharp Cheddar. 6 to 10 -- cheese-like
products containing different levels of coconut protein ingredients. Data with a common
letter do not differ significantly (P> 0.05)
50
40
30
20
10
0
1
2
3
4
5
Commercial cheeses
6
7
8
9
10
Figure 31. Comparison of cohesiveness as determined by the Texture Profile Analysis between
cheese-like products and commercial cheeses: 1 to 5 -- cheese-like products containing
0%(1), 10%(2), 20%(3), 30%(4) Na-caseinate, and 15%(5) non-fat dry milk. Commercial
cheeses from left to right -- Cream, Processed, and Sharp Cheddar. 6 to 10 -- cheese-like
products containing different levels of coconut protein ingredients. Data with a common
letter do not differ significantly (P> 0.05)
8
6
4
2
0
1
2
3
4
5
Commercial cheeses
6
7
8
9
10
Figure 32. Comparison of springiness as determined by the Texture Profile Analysis between
cheese-like products and commercial cheeses: 1 to 5 -- cheese-like products containing
0%(1) 10%(2), 20%(3), 30%(4) Na-caseinate, and 15%(5) non-fat dry milk. Commercial
cheeses from left to right -- Cream, Processed, and Sharp Cheddar. 6 to 10 -- cheese-like
products containing different levels of coconut protein ingredients. Data with a common
letter do not differ significantly (P> 0.05)
COCONUT MEAT
Blending with 0.5 M NaCl solution (meat :
solvent=l:1)
Squeezing
COCONUT MILK
Defatting
DEFATTED COCONUT MILK
Heat to 95°C at water bath
for 15 min
COAGULUM
Pass through cheese cloth for
30 min
WET CURD
Add emulsifier, guar gum,
coconut fat, sodium citrate,
etc.
Mix vigorously at 60-70°C
SMOOTH EMULSION
Mix
CHEESE-LIKE PRODUCTS
Pack into container
Store under refrigeration
AGED CHEESE-LIKE PRODUCTS
Figure 33.
Schematic diagram for manufacturing cheese-like products
from coconut curd and guar gum.
62
45
40 —
35 —
30 —
25 —
20 —
15 —
10 —
5
2
I
3
I
4
I
5
I
6
I
7
8
Content of gum(%)
Figure 34.
Hardness of coconut cheese-like product from coconut curd at
various guar gum contents.
63
60
50 —
40 —
30 —
20 —
10
—
2
3
4
5
6
7
8
Content of gum (%)
Figure 35.
Cohesiveness of coconut cheese-like product from coconut
curd at various guar gum contents.
64
7
6 —
5 —
4 —
3 —
2 —
1
2
l
l
l
l
l
3
4
5
6
7
8
Content of gum (%)
Figure 36.
Springiness of coconut cheese-like product from coconut curd
at various guar gum contents.
65
SHREDDED COCONUT MEAT (25 kg)
COCONUT MILK I (17.5 kg)
RESIDUE I (10 kg)
Mix with 1% NaCl
solution (35 kg),
45°C, 10 min
RESIDUE II
Add 1.2% NaCl solution (72.5 kg, 70°C)
(7 kg)
Defat with
separator
COCONUT MILK II (38 kg)
CREAM I (9 kg)
Remove cream
by floatation CREAM II
DEFATTED MILK I (21 kg)
(36 kg)
DEFATTED MILK II (36 kg)
U.F. (25 - 35 psi, 280 ml/min)
PERMEATE
RETENTATE (7.5 - 8.0 kg)
Spray dry (Inlet temp 180 - 200°C,
Outlet temp 80 - 90°C, Flow rate 8 l/hr)
COCONUT PROTEIN CONCENTRATE (0.25 - 0.35 kg)
Figure 37 Schematics for coconut protein concentrate preparation and yield (Thailand).
SHREDDED COCONUT MEAT (6 kg)
Press with water
RESIDUE (2.4 kg)
COCONUT MILK (4.2 kg)
Defat with cream separator
CREAM (2.2 kg)
DEFATTED MILK (5 kg)
Heat while stirring slowly to 90°C
Adjust pH to 5.0 and heat to 95°C
Add NaCl (85 - 95 gm)
Remove from heat
Scoop curd info cheese-cloth layered mold
Wrap curd with cheese-cloth
Press with 10 kg weight overnight at 5°C
Remove from mold
TOFU-TYPE PRODUCT (0.28 kg)
Moisture 71.26%
Protein
16.49%
Fat
6.13%
Figure 38. Schematics for tofu-type coconut curd processing and yield (Thailand).
DEFATTED COCONUT MILK or CONCENTRATED COCONUT MILK
by ULTRAFILTRATION
Add salt
Adjust pH to 3.5
Heating up to 98°C
PRECIPITATE
PRECIPITATE
Filter and Press
HEAT-INDUCED CURD
SALT-INDUCED CURD
Adding emulsifier, gums
and/or coconut flour
sieved through #20 sieve
Mixing
Mixing
EMULSION FORMATION and MOLDING
CHEESE-LIKE PRODUCTS
Figure 39. Schematic diagram for manufacturing cheese-like products from coconut protein curd
(proposed).
PARTIALLY DEFATTED COCONUT MILK or CONCENTRATED
COCONUT MILK by ULTRAFILTRATION
Heat to 98 °C or
Adjust pH to 3.5
Allow stand for 2 hr
COAGULUM
Pass through cheese cloth
Press
WET CURD
Dry at 60-70 °C
COCONUT PROTEIN
ISOLATE
Add emulsifier, gums and/or
coconut flour sieved through
a 60 mesh screen
Mix
SMOOTH EMULSION
Mix
CHEESE-LIKE PRODUCTS
Pack info container
Store under refrigeration
AGED CHEESE-LIKE PRODUCTS
Figure 40. Schematic diagram for manufacturing cheese-like products from coconut milk (proposed).
PARTLY DEFATTED COCONUT MILK
Stir slowly and heat up to 98°C
Maintain the temp for 10 min without stirring
Cool down with cold wafer
Curd Formation
Drain whey through cheese cloth
Gum, disodium phosphate, Citric acid,
Sodium citrate, Potasium sorbate,
Additional coconut fat (if necessary)
Mix
Press the curd covered with cheese cloth
in a mold and refrigerate at 5°C overnight
MODIFIED CHEESE-LIKE PRODUCT
Figure 41. Application of processed cheese-like product formulations to tofu-type processing
(proposed).
CHAPTER 2
THE TESTING OF THE DEVELOPED
COCONUT CHEESE PRODUCTION TECHNOLOGY
AND EQUIPMENT SPECIFICATIONS
Prepared by
Dr. Sukoncheun Sringam,
Department of Food Science and Technology,
Faculty of Agro-Industry,
Kasertsart University,
The Kingdom of Thailand
71
INTRODUCTION
The coconut cheese production technology was studied by Texas Engineering Experiment
Station (TEES), Texas A&M University. Towards the end of the project (June-September 1993), the
small pilot-scale productions of cheese-like product and tofu-type product were conducted at Kasetsart
University (KU). The already available equipment was used with an ultrafiltration unit provided by
TEES.
In order to confirm the final coconut cheese production technology, the following TEES reports
were reviewed:
1.
Literature Review and Outline of Work Planned
2.
Research Report I
3.
Interim Report II
4.
Interim Report III
5.
Final Report
The production technology was confirmed with minor alterations. The list and specifications
of equipment required for three production capacities were thereafter provided.
FINDINGS AND RECOMMENDATIONS
The information of processing steps and conditions of coconut protein concentrate, coconut
cheese-like and coconut tofu-type productions were collected from the reports and concluded in
Figures 1, 2 and 3.
1.
Coconut protein concentrate production
Extraction step
The report indicated that extraction of coconut milk with 0.5 M salt solution at 1:2 w/v could
increase the protein yield by 20 per cent (Research Report I, p. 18). The estimation based on the
protein content of coconut milk was 2.0 per cent when coconut meat:water was 1:1 and 1.2 per cent
when coconut meat:0.5 M salt solution was 1:2, respectively. This was too rough an estimation
because the yielded coconut milk volumes were not the same as the extractant volumes. From my
experience, if 1 kg of coconut milk was used, the former coconut milk yield should be 1.6 kg and
the latter should be 2.6 kg. The protein in the former coconut milk could be calculated to be
0.02x1.6 = 0.032 kg, and in the latter one to be 0.012x2.6 = 0.031 kg (not significantly different).
The coconut meat to water ratio of 1:2 also did not increase the extractable protein by the same
reason. The high content of water increases the time required in the ultrafiltration step, therefore a
coconut meat to water ratio of 1:1 is recommended. By using two-stage countercurrent extraction
procedure, the yield of oil and protein contents in coconut milk increased by 14.5 per cent
(Nethivaranont, 1986) is thus recommended.
72
Coconut meat
Grater
Mixer
meat:0.5 M NaCl soln.=1:2
35-45°C 4 min
Pulp press
Cream separator
Westfalia SA7-06
7000 rpm 50,60°C
Defatted milk
Cream
Prefiltration
120 mesh
Ultrafiltration
hollow fiber, MWCO5000
pressure 25-35 psi
concentration factor 8
diafiltration to 30% salt
and sugar
Spray dryer
APV, inlet temp 180, 190°C
outlet temp 60-70, 80°C
Sieving
40 mesh
Coconut Protein
Concentrate
Figure 1
Coconut Protein Concentrate production (from TEES reports, written
research paper and provided work instruction)
73
Concentrated coconut milk
Salt solution preparation
add citric acid
0.6%
disod. phosphate
0.85%
sod. citrate
0.80%
pot. sorbate
0.10%
heat to 60°C
Salt solution
Coconut protein concentrate (50 %)
Mixing
1. mix with 50% salt soln. at low speed
to complete hydration
2. add 50% CPC and 30% salt soln while
mixing
3. add 20% salt soln while mixing until
smooth, homogeneous.
Temperature during mixing 60°C
Molding
pour into cheese mold
and allow to cool
Coconut cheese like product
Figure 2
Coconut cheese-like product production (from TEES reports)
74
Defatted coconut meat (2.5 kg)
Heat Coagulation
stirring slowly and
heating up to 98°C hold at
98°C 10 min without stirring
Cooling
cooling with cold water for 10 min.
Whey draining
draining whey through cheese
cloth, squeezing curd with
cheese cloth
Pressing
pressing the curd wrapped with
cheese cloth in mold overnight
Coconut Tofu-type
product (0.1 kg)
Figure 3
Coconut Tofu-type product production (from TEES reports)
75
Pasteurization step
Coconut milk is highly perishable. When the coconut protein concentrate was produced at
Kasetsart University, the coconut protein solution was spoiled if the process was delayed. In
commercial-scale production that involves a large volume of coconut milk and delay time sometimes
occurs, the pasteurization step after the extraction step is therefore recommended. Holding coconut
milk at 60°C for four minutes reduced microbial load to 10 per cent (Hogenmaier, 1977) Protein
denatures at 70°C and forms curd on heating surface; thus, it should not be heated to 70°C or higher.
Cream separation step
The purpose of the cream separation step was to separate the coconut milk into two fractions,
cream and defatted milk. The two-phase centrifuge was used at TEES and KU. From the observations
at KU, there was a third fraction of insoluble solid adhered inside the centrifuge bowl. The insoluble
protein was believed to surround oil globules in the native forms and was sheared off by centrifugal
force. To recover the insoluble protein fraction, three-phase centrifuge should be used. The recovered
insoluble protein will be discharged from the centrifuge bowl at high solid concentration and should
be mixed with concentrate from ultrafiltration before spray drying.
Ultrafiltration step
The ultrafiltration step follows right after the cream separation step where the coconut milk is
centrifuged at 60°C. The friction from the high pressure pump during circulation will increase the feed
temperature. If the temperature is too high
70°C), the protein denaturation will occur and
ultrafiltration will stop due to clogging of protein particles. The feed temperature should be kept at
around 50-55°C before and during filtration, thus a cooling system is necessary during ultrafiltration.
The type of membrane and configuration of the membrane are very important. The reports did
not reveal the testing of the membrane, other than Romicon PM10 and Romicon PM5 membrane with
the molecular weight cut-off (MWCO) 10,000 and 5,000. The PM5 membrane gave an initial flux of
2
2
20 l/m .hr, but the flux decreased to about 4 l/m .hr within 60 minutes (Kwon et al., 1996). The rapid
change of flux rate showed that the PM5 membrane might not be a suitable membrane for coconut
protein solution. From discussion with a UF supplier (Niro Hudson, Inc.), it was learned that the
coconut protein solution also contains coconut oil, which has hydrophobic properties; the membrane
should he hydrophillic type to prevent fouling of coconut oil on the membrane. However, the supplier
must test run with the actual coconut protein solution before providing the most suitable membrane.
As for the configuration of the membrane, a spiral wound element has higher filter area than
the hollow fibre for the same space and is commonly used in milk whey concentration, and is
therefore recommended.
2.
Coconut cheese-like production
In coconut cheese-like production UF concentrated coconut milk is one of the ingredients.
Concentrated coconut milk can be prepared by pressing coconut milk without adding water. To avoid
long handling time of coconut milk concentration by ultrafiltration, pressing coconut meat without
adding water to produce concentrated coconut milk is recommended.
3.
Coconut tofu-type production
There are no findings and recommendations for coconut tofu-type production.
76
CONFIRMATION OF COCONUT CHEESE PRODUCTION TECHNOLOGY
The coconut cheese production technology of TEES was reviewed and confirmed with minor
alterations recommended, as detailed below.
Coconut protein concentrate production
1.
Change the coconut meat to 0.5 M NaCl solution ratio of 1:2 to coconut meat to water ratio
of 1:1 in the coconut milk extraction step.
2.
Add a pasteurization step after the coconut milk extraction step.
3.
Three-phase centrifuge is used instead of two-phase centrifuge in the cream separation step.
4.
Change the UF membrane configuration from hollow fibre to spiral wound.
5.
Change the UF membrane type from Romicon PM5 to other heat resistant hydrophillic
membrane.
6.
Add cooling system in ultrafiltration unit to maintain the retentate temperature during filtering.
The recommended process line for CPC production is shown in Figure 4.
Coconut cheese-like product production
1.
Prepare concentrated coconut milk by pressing coconut meat without adding water instead of
passing coconut milk through the ultrafiltration unit.
Coconut tofu-type product production
No alteration is recommended.
DESIGN OF SPECIFICATIONS
In designing the specifications for coconut cheese production, major equipment suppliers
(coconut meat shredder, centrifuge, ultrafiltration and spray drier) were consulted for available
performance features and throughout capacities. It is fortunate that most equipment, even if available
in certain models and capacities, is usually fabricated to meet specific conditions or requirements of
the user. The specification, therefore, features only the specific performance requirement and capacity,
not the engineering specification such as power consumption, size of motor, etc.
The production capacities were set at 1,000 kg coconut meat for pilot small-scale production,
5,000 kg coconut meat for small- to medium-scale, and 50,000 kg coconut meat for medium- to largescale production.
Coconut milk is highly perishable and the coconut protein concentrate (CPC) production process
involves many steps, To reduce the risk of spoilage, besides adding a pasteurization step, the material
should flow continuously with minimum delay time. The following step must start as soon as there
is enough material to run continuously. The time for each step is kept at constant. The material
balance on each step was estimated from partially available data of materials and material compositions
77
from the TEES reports (Figure 5) and our group data (Sringam, 1993, Arkanit, 1996). The accuracy
of the estimation is believed to be
15 per cent. The estimated material balance of recommended
production is shown in Figure 6.
78
Coconut meat (1 part)
Shredder
Mixer 1
Screw press 1
Water (1 part)
Coconut milk
Mixer 2
Sieving
Pasteurizing
Screw press 2
dilute milk
Residue
Three phase centrifuge
Defatted milk
Insoluble
Cream
Protein
Prefiltration
Ultrafiltration
Spray dryer
Sieving
Coconut Protein
concentrate
Figure 4
Recommended process line for Coconut Protein Concentrate production
79
Coconut meat (199 kg)
protein 4.4, 3.8 %
oil
32.9, 35.2%
Moisture 48.3, 40.9%
Cream ( -kg)
Defatted ( -kg)
71.7% of oil in meat
protein 0.8 %
oil
0.6%
moisture 96%
Retentate ( -kg)
protein 8.6%
Coconut Protein
Concentrate (1.14-1.90 kg)
protein 52.1%
oil
13.7%
moisture 5%
other solid (by difference) 29.2%
(protein/other solid = 1.78)
Figure 5.
Partially available material balance and composition of coconut protein concentrate
production (from TEES reports)
80
Coconut meat (199 kg)
protein 3.16 %
oil
27.23 %
Coconut milk (160 kg)
protein 1.5% %
oil
16.0%
Cream (48 kg)
Defatted milk
and insoluble
protein (112 kg)
protein 0.4%
protein 1.97 %
oil
oil
52.0%
0.57%
moisture 96 %
Retentate (CF=8) (14 kg)
protein 14.18%
oil
4.10%
other solid 7.97%*
(assume 10% loss in permeate)
Coconut Protein
Concentrate (1.14-1.90 kg)
protein 52.0%
oil
15.0%
moisture 4.0%
other solid 29.0%
* assume from protein/other solid ratio of 1.78 in CPC.
Figure 6.
Estimated material balance of recommended Coconut Protein Concentrate
production (assume no loss in handling)
81
Since each step was set at constant (4 hours for 1,000 kg coconut meat production and 8 hours
for the other two productions), the flow throughout rate of each step could be calculated. The number
of units required for each step was estimated close to the available sizes or capacities. The material
balance and throughout rate of each step are shown in Tables 1 and 2.
Table 1
Material balance of three coconut protein concentrate (CPC) production capacities
Weight, kg. for production capacity
Material
1
2
3
Coconut meat
Coconut milk
Coconut cream
Defatted milk and insoluble protein
Permeate
Retentate
Coconut Protein Concentrate
l,000
1,600
480
1,120
980
140
38
5,000
8,000
2,400
5,600
4,900
700
190
50,000
80,000
24,000
56,000
49,000
7,000
1.900
Table 2
Throughout rate of each step in CPC production
Throughout rate kg/hr for capacity
Processing step
(Time for each step, hr)
Washing
Shredding
Mixing 1 and Pressing 1
Mixing 2 and Pressing 2
Sieving and pasteurization
Centrifuge
Prefiltration and ultrafiltration
Spray drying
Coconut protein concentrate
1
2
3
4
8
8
250
250
550
400
400
400
280
35
9.5
625
625
1,375
1,000
1,000
1,000
700
87.5
23.75
6,250
6,250
13,750
10,000
10,000
10,000
7,000
875
237.5
82
The production of coconut cheese-like product uses CPC produced the previous day and be of
batch type. The formulation of coconut cheese-like products are shown in Table 3. The production
of coconut tofu-type product starts from defatted coconut milk which comes from coconut meat at the
same capacity as for CPC production. Its production involves a large volume of defatted milk so the
continuous process is preferred to the batch process.
Table 3
Formulation of three coconut cheese-like products (from work instruction
provided to Kasetsart University from TEES)
Product type
Ingredients, %*
Spread
Medium
Hard
Coconut protein concentrate
Concentrated coconut milk
Citric acid
Disodium phosphate
Sodium citrate
Potassium sorbate
Flavour
Colour
Total
48.65
49.00
0.60
0.85
0.80
0.10
tr
tr
100.00
57.50
40.00
0.60
0.85
0.80
0.10
tr
tr
100.00
61.65
36.00
0.60
0.85
0.80
0.10
tr
tr
100.00
* Formulas can be varied depending on chemical compositions of raw materials.
83
List of Equipment
Coconut Protein Concentrate Production
Coconut Meat
Spray Drum Washer
Coconut Meat Shredder
Horizontal Trough Ribbon Mixer
Screw Press
Shell and Tube Heat Exchanger
Three Phase Centrifuge
Ultrafiltration Unit
Spray dyer
Coconut Protein Concentrate
(CPC)
84
Coconut Cheese - like Product
Concentrated
Coconut Protein
Coconut Milk
Concentrate
Steam Jacket Kettle
with Paddle Agitator
Steam Jacket Kettle
with Planetary Mixer
Framing tray
Cooling Tunnel (Cold room)
Cutting Machine
Wrapping Machine
Coconut Cheese - like
Product
85
Coconut Tofu - type Production
Defatted Coconut Milk
Scraped Surface Heat Exchanger
Cooling Unit
Screw Decanter
Molding and Pressing Machine
Wrapping Machine
Coconut Tofu - type
Product
86
Specifications of equipment
Coconut Protein Concentrate Production
1.
Spray drum washer
A drum of 3 cm stainless steel slats, spaced 1½ cm apart so as to retain the coconut meat
pieces while allowing debris to be washed through. The drum inner surface is lined with 4 baffles at
a 30° angle along the length of the drum for turning and moving the coconut meat pieces toward the
outlet end. The drum, which rotates slowly, is inclined to the horizontal. The spray rod fitted with
water jets is located at the centre of the drum.
The speed of rotation and angle of inclination are adjusted to control the duration of the
washing cycle.
2.
Capacity, kg coconut meat
Flow rate, kg/hr
1,000
5,000
50,000
250
625
6,250
No. of unit required
0 (Water tank)
1 (90 cm.d x 150 cm.1)
4 (120 cm.d x 250 cm.1)
Coconut meat shredder
The shredder consists of a stainless steel closed drum with sharp points standing 1 mm from
the outer surface. The points align 4 mm apart and at a 45° angle along the length of the drum. The
parallel lines of points are 4 mm apart. The drum rotates at high speed and shreds coconut meat pieces
(
of a nut) which is fed to the side of the drum through a slot. The side slat, beneath the slot
along the length of the drum, holds the coconut against the drum. All food contact parts are made of
stainless steel and sanitary designed.
The most common size of the drum is 12 cm diameter and 20 cm long, and the speed is 300500 rpm.
The speed and the size of the drum are adjusted to obtain the desired capacity rate.
Capacity, kg coconut meat
Flow rate, kg/hr
1,000
5,000
50,000
250
625
6,250
87
No. of unit required
2 (12 cm.d x 20 cm.1)
4 (12 cm.d x 25 cm.1)
16 (20 cm.d x 38 cm.1)
3.
Horizontal trough ribbon mixer
Two counteracting ribbons are mounted on the same shaft horizontally along a trough. One
moves the shredded coconut-water mixture in a forward direction, while the other moves it quickly
in the backward direction, resulting in mixing and moving the mixture forward continuously. All food
contact parts are made of stainless steel.
The size of the trough determined the capacity rate.
Flow rate, kg/hr
Capacity, kg coconut meat
1,000
5,000
50,000
4.
mixer 1
mixer 2
550
1,375
13,750
400
1,000
10,000
No. of unit required
mixer 1
mixer 2
1
1
4
1
1
4
Screw Dress
The screw press consists of a screw shaft of variable diameter rotating inside a perforated
barrel. The screen has 0.25 mm opening. Parts that make contact with the coconut meat mixture are
made of stainless steel. The speed of the screw shaft and the die plate opening are adjusted to give a
compression ratio of not less than 10, and with moisture content of the press cake not more than
45 per cent.
The size of the barrel and screw shaft determine the capacity rate.
Flow rate, kg/hr
Capacity, kg coconut meat
1,000
5,000
50,000
5.
screw press 1
No. of unit required
screw press 2 screw press 1
550
1,375
13,750
400
1,000
10,000
screw press 2
1
1
4
1
1
4
Shell and tube heat exchanger
The heat exchanger consists of a number of 2-inch diameter stainless steel tubes enclosed in a
horizontal shell. The coconut milk is fed through the tubes, while 95 2°C hot water is counter-fed
through the shell.
The length of the tubes, the rates of coconut meat and hot water are adjusted to yield outlet
temperature of coconut milk 62 2°C at desirable capacity rate.
Capacity, kg coconut meat
Flow rate, kg/hr
No. of unit required
1,000
5,000
50,000
400
1,000
10,000
1
1
1
88
6.
Three-chase centrifuge
The centrifuge is of disc bowl type that can separate coconut milk into three fractions: light
liquid phase (cream), heavy liquid phase (defatted milk) and solid (insoluble protein). The solid can
be ejected from the bowl within a few seconds while the centrifuge is running at full speed. The bowl
speed should be around 7,000 rpm or higher. All food contact parts must be made of stainless steel
and can withstand the temperature up to 70°C. The feed rate and cream or defatted milk outlet can
be adjusted to give the desirable capacity and cream concentration.
7.
Capacity, kg coconut meat
Flow rate, kg/hr
No. of unit required
1,000
5,000
50,000
400
1,000
10,000
1
1
1
Ultrafiltration unit
Spiral wound with 4 mil spacer, built of membrane which is heat-resistant up to 70°C and
compatible with coconut protein solution. The membrane has molecular weight cut-off (MWCO) of
2
5,000. The working flux rate is at least 20-25 l/m hr. The membrane elements are arranged in a
parallel fashion to obtain the necessary filter area. The feed tank must be temperature controlled at
50-55°C. The unit must be set up in the way that feed can be periodically fed in and concentrate or
retentate can be periodically drawn out.
8.
Capacity, kg coconut meat
Flow rate, kg/hr
1,000
5,000
50,000
280
700
7,000
No. of unit required
1 (2 - 3 elements)
1 (4 - 6 elements)
10 (4 - 6 elements)
Spray dryer
The solution is fed to an atomizer and dispersed into the drying chamber as a fine mist. The
atomizer is of a centrifugal type. The fine mist of feed material and hot air flows are concurrent. The
inlet and outlet hot air temperature can be controlled to cover the required inlet temperature of
180-190°C and outlet temperature of 60-70°C. The drying chamber is equipped with wall sweeping
device to prevent powder deposits on the wall. The dryer outlet for the powder is also equipped with
a cooling facility to cool down the powder to 30 2°C and shaking screen of 40 mesh opening.
Capacity, kg coconut meat
1,000
5,000
50,000
Flow rate, kg/hr
35
87.5
875
89
No. of unit required
1
1
2
Coconut cheese-like product production
1.
Steam jacket kettle with paddle agitator
The stainless steel kettle with a jacket covers not less than 75 per cent of the holding volume
capacity. The jacket is equipped with steam inlet, condensate outlet, steam pressure control valve and
safety valve. The kettle has an outlet pipe with a control valve at the bottom. The paddle is a wide
blade, fixed to a rotating shaft. The shaft is mounted centrally in the kettle and rotates at about
20-30 rpm.
2.
Capacity, kg product
No. of batch/day
No. of unit required
60
300
3,000
1 (60 kg)
3 (100 kg)
12 (250 kg)
1 (100 1)
1 (150 1)
3 (350 1)
Steam jacket kettle with planetary mixer
The stainless steel kettle with a jacket covers not less than 75 per cent of the holding volume
capacity. The jacket is equipped with a steam inlet, condensate outlet, steam pressure control valve
and safety valve. The two mixing elements of gate type move in a planetary path, visiting all parts
of the kettle with a small clearance between each other and the kettle wall. The mixing elements can
be moved up after use.
3.
Capacity, kg product
No. of batch/day
No. of unit required
60
300
3,000
1 (60 kg)
3 (100 kg)
12 (250 kg)
1 (100 1)
1 (150 1)
3 (350 1)
Framing tray
The stainless steel rectangular frame with separate stainless steel bottom sheet.
Capacity, kg product
No. of unit required*
60
300
3,000
10 (50x65x2.0 cm )
3
32 (50x65x2.0 cm )
3
80 (50x65x2.0 cm )
3
* Change according to the required size of the product.
90
4.
Cooling tunnel
A tunnel 70 cm wide and about 3 to 4 m long having dry cold air (0°C) blowing from the
ceiling, with belt conveyor transports framing trays from one end to another. The speed of the belt
is adjustable in the range of 100-200 m/min to reduce the temperature of the product from around 60
to 5-10°C.
No. of unit required
Capacity, kg product
60
300
3,000
5.
- (cold storage
room)
1
3
Cutting machine
Two sets of 9 parallel cutting wire blades, one set parallel in one direction 6.5 cm apart,
another set in perpendicular direction 5.0 cm apart. The distance between wires determines the length
and width of the cut piece. The wire blades move downward through framed product and cut it into
100 pieces by two actions.
No. of unit required
Capacity, kg product
60
300
3,000
6.
1
1
3
Wrapping machine
This wraps a rectangular piece by envelope folding. The dimensions can be adjusted with
maximum permissible tolerance
10 per cent. The speed is adjustable from 50-200 pieces/min. The
packing material can be aluminium foil or laminated plastic.
Capacity, kg product
No. of pieces*
No. of unit required
60
300
3,000
960
4,800
48,000
1
1
1
* 62.5 gm piece.
91
Coconut tofu-type product production
1.
Scraped surface heat exchanger
The continuous heat exchanger consists of a cylinder containing a heating medium (super
saturated steam) surrounding an internal cylinder containing the material to be heated. The feed stock
is fed from one side and flows out from the opposite side. The heated cylinder wall is scraped
continuously by a revolving blade attached to a centre shaft.
Capacity, kg defatted milk
1,120
5,600
56,000
2.
Flow rate, kg/hr
No. of unit required
280
700
7,000
1
1
1
Cooling unit
Shell and tube cooling unit connected to scraped surface heat exchanger. The length of the tube,
temperature of the cooling medium and rate of defatted coconut milk are adjusted to reduce the
temperature from 95°C to 60°C at the desirable capacity rate.
Capacity, kg defatted milk
1,120
5,600
56,000
3.
Flow rate, kg/hr
No. of unit required
280
700
7,000
1
1
1
Screw decanter
The continuous horizontal solid bowl centrifuge. The feed is continuously separated to liquid
and solid phase. The clarified liquid is discharged through a dam plate of the bowl at the opposite side
of the feed pipe. The solid is discharged by screw conveyor. Bowl speed is about 6,000 rpm.
Capacity, kg defatted milk
Flow rate, kg/hr
No. of unit required
1,120
5,600
56,000
280
700
7,000
1
1
1
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4.
Molding and pressing machine
3
Set of 20 attached stainless steel rectangular frames of 5.0 x 6.5 x 6 cm , with separate
perforated stainless steel bottom sheet. The frames move underneath a set of match pressure plates.
Each plate presses down inside each frame at enough pressure to reduce the moisture content of the
product in the frame to about 70 per cent. After pressing, the bottom sheet is removed and the pressed
products are pushed down from the frames.
Capacity, kg defatted milk
Flow rate, pieces*/hr
No. of unit required
160
800
8.000
1
1
4
1,120
5,600
56,000
3
* 125 gm piece of 5.0 x 6.5 x 4 cm size.
5.
Wrapping machine
This wraps a rectangular piece by envelope folding. The dimensions can be adjusted with
maximum permissible tolerance
10 per cent. The speed is adjustable from 50-200 pieces/min. The
packing material can be aluminium foil or laminated plastic.
Capacity, kg product
No. of unit required
1,210
5,600
56,000
1
1
1
Note: Wrapping machine will be used intermittently.
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List of auxiliary supplies/equipment
1.
Container and transport mean between steps
1.1 Washing - Shredding
- Bucket/man (small to medium scale)
Bucket conveyor (large scale)
1.2 Shredding - Mixing
- same as 1.1
1.3 Screw press 1 - Pasteurization
- Tank with 120 mesh sieve at inlet and centrifugal
pump at outlet pipe for coconut milk
same as 1.1 for residue
1.4 Screw press 2 - Screw press 1
- Tank with centrifugal pump at outlet pipe for
diluted coconut milk
same as 1.1 for residue
1.5 Cream separation - Ultrafiltration - Tank with 120-mesh sieve at inlet pipe and
centrifugal pump at outlet pipe for defatted
coconut milk
Bucket for insoluble protein
Tank for cream
1.6 Ultrafiltration - Spray drying
1.7 After spray drying
2.
- Tank with outlet centrifugal pump for retentate
High density polyethylene (HDPE) bag for short
storage and aluminium foil laminated with HDPE
for long storage
Boiler
For generating supersaturated steam which is used for heating water used in extraction step and
pasteurization step and also as a heating medium in scraped surface heat exchanger.
3.
Pipe and accessory
For connecting one unit and another where necessary.
4.
Cold storage room
For storage of coconut cheese-like product and coconut tofu-type product before delivery. It
can also be used for cooling down coconut cheese-like product before cutting in case of smallscale production. The temperature of the room should be controlled at 3
1°C.
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Conclusion
The specification is composed of performance requirement and capacity. The performance
requirements were derived from TEES report on laboratory scale coconut cheese production and from
long experience in the coconut processing field. The capacities were derived from estimated material
balances when the coconut meat to water ratio was 1: 1. There is always variation among different lots
or sources of coconuts, therefore, the estimation is believed to be
15 per cent accurate.
The product yields are very low, and the production required many expensive pieces of
equipment, thus not promising as main products. Nevertheless, there is the cream from cream
separation step as a co-product. The cream can be used as a starting material for virgin coconut oil
production. Virgin coconut oil is of high quality that may be sold at a high price, and compensates
for low yield of coconut cheese product. However, economic feasibility should be studied before
introducing the coconut cheese production.
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Contacted equipment suppliers
Coconut shredder. screw press
Seng Sangar Ltd. Part.
33-35 Nakorn Kasem
Yoawaraj Road, BANGKOK
Tel: 222 2771, 224 8696
Centrifuge
Saito Separator Ltd.
8-7, Haneda 1-Chome, Ohta-ku
TOKYO 144
Tel: (813) 3743.1116
Through Mr. Vanida Kosolthanasangor
Boonradom Trading Co. Ltd.
29/6 Charoen Nakorn Villa
Soi Charoen Nakorn 12
BANGKOK 10600
Tel: 439 4448/9, 439 5757
Mr. Chawalit Petnamsin
Sepatech Engineering Service Co. Ltd.
93/20 Ladphroa Soi 97
Bangkapi
BANGKOK 10310
Tel: 932 3140/4, 932 3138
Mr. Chairat Jiwanarungsan
Alfa Laval (Thailand) Ltd.
1042 Soi Poonsin, Sukhumvit 66/l
Bangjak
BANGKOK 10260
Tel: 361 2801-5
Ultrafiltration
Mr. Robert Keefe
Niro Hudson, Inc.
1600 O’Keefe Road
Hudson, WI 54016
Tel: (715) 386 0176
Mr. Prapan Ariyamethee
Liquid Purification Engineering Co. Ltd.
63/49-50 Bangyai City Center
Talingchan-Bangbuathong
Nonthaburi 11140
Tel: 595 0552/3, 595 0295
96
Spray dryer
Ms. Monthicha Meethong
GEA (Thailand) Co. Ltd.
7th floor, Golden Pavilion Building
153/3 Soi Mahadlekluang 1
Rajdamri Road
BANGKOK
Tel: 652 1550
Diregrit Lekskul
APV (Thailand) Ltd.
Won Waiwait Building, 3rd Floor
889 Moo.5, Srinakarin Road
Samutprakarn 10270
Tel: 398 0024 (5 lines)
Heat exchanger. boiler, kettle. mixer
Mr. Sirot Nukooltham
New Way Manufacturing Co. Ltd.
80/6 Moo 2, Nadee Muang
Samutsakorn 74000
Tel: (034) 412670
97
References
Arkanit, K. (1996): The Production of Canned Reconstituted Coconut Milk. Master Thesis, Graduate
School, Kasetsart University, Bangkok, Thailand. 84 pp. (in Thai)
Brennan, J.G., Butters, J.R., Cowell, N.D. and Lilley, A.E.V. (1990): Food Engineering Operation.
Third edition. Elsevier Applied Science, London and New York. 700 pp.
Hagenmaier, R. (1977): Coconut Aqueous Processing. University of Carlos, Cebu City, Philippines.
313 pp.
Koseoglu, S. (1996). Head, Membrane Separation Section Food, Protein R&D Center, Texas A&M
University (personal communication)
Kwon, K.S., Bae, D., Park, K.H. and Rhee, K.C. (1996): Aqueous Extraction and Membrane
Techniques Improve Coconut Protein Concentrate Functionality. J. Food Sci. 61: 753-756.
Nethivaranont, S. (1986): Stability of Coconut Milk. Special Problem. Graduate School, Kasetsart
University (in Thai)
Sringam, S. (1993): Development and Testing of Coconut Cheese Production Technology (in
Thailand). Project US/RAS/90/132, UNIDO.
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