Chapter 1
General Introduction
Chapter 1A
Coconut
The story of the coconut and its presence around the globe is one in which
evolution, immigration, trade, cultural practices and the forces of nature, all
play a part (Foale, 2003). The term coconut can refer to the entire coconut
palm, the seed, or the fruit, which botanically is a drupe or a nut. The coconut
palm (Cocos nucifera) is a member of the family Arecaceae (palm family). The
name Cocos probably derives from a Portuguese word meaning monkey
because its nut, bearing three germinating pores, resembles a monkey face.
Its specific name derives from Latin, meaning nut-bearing. In Sanskrit, it is
called kalpa vriksha (a mythological tree supposed to grant desires) because
of its versatile contribution to mankind that can provide all the necessities of
life. This species is known to have several of uses as a source of food, drink,
fiber,
construction
material,
charcoal,
and
oil
(used
in
cooking,
pharmaceuticals, industrial applications and biofuels). Coconut is planted over
12 million hectares of land across 93 tropical countries. India is currently one
of the top producers of coconuts in the world, with annual production of
11,930,000 tonnes in 2013 (Table 1A.1).
1A.1. Plant and fruit description
The coconut tree belongs to the family Arecaceae in the order Palmales. The
genus, Cocos, is monospecific, with a pantropical distribution, predominantly
in coastal areas between latitude 20 N and S of the equator (Figure 1A.1).
The species varies greatly in tree height, fruit shape and size. All coconut
cultivars are classified distinctively in two groups: tall and dwarf types. The tall
types are referred to as var, typica Nar. while dwarf types as var. nana (Griff.)
Nar. The tall varieties are commonly cultivated in all the coconut growing
regions of the world. Their fruits are ‘medium to large’ in size. The dwarf
1
varieties are characterized by their short stature and smaller nuts of varying
colours, e.g. green, yellow and orange. They are presumed to have originated
from the taller palms either through mutation or by inbreeding. The cultivars
are usually diploids and the chromosome number is 2n=32 (Ray, 2002). The
coconut palm can grow upto 30 meters in height and live for 80 to 100 years.
The stem has only one terminal growing point, no axillary vegetative buds and
rarely has suckers from the underground portion of the stem. As a
monocotyledonous plant, the coconut palm has adventitious root system. The
crown of a mature plant usually has about 30 to 40, open, 3 to 6 meter long
leaves (fronds), 10 to 14 of which subtend fruit bunches at different stages of
development. At each leaf, both staminate (male) and pistillate (female)
flowers are borne on an axillary inflorescence. Dwarf forms may begin
flowering in 3 years while the tall variety takes 5 to 7 years to flower (Janick
and Paull, 2008). The fruit is formed from a flower with three carpels, only one
of which develops. The coconut fruit contains only one seed, which is the
largest known. The embryo itself is small and located near the stem end.
Initially, the endosperm is a liquid containing free nuclei. As the endosperm
matures, cell walls form around the nuclei and the endosperm solidifies into
an oil rich layer referred to as “coconut meat”. If a mature coconut is left
undamaged, the embryo can germinate within the coconut since there is no
dormancy period. The base of the embryo swells (referred to as “coconut
apple”) and eventually digests the endosperm. The germinating seedling
eventually extends through one of the eyes (Pooja, 2010).
A coconut tree can produce up to 75 melon-sized fruits per year. Each fruit
can weigh 1- 2 kg (depending on the variety) and is composed of 35% husk,
2
12% shell, 22% kernel and 25% (w/w) water. The coconut is the entire fruit,
and botanically it is a drupe, consisting of pericarp and mesocarp (husk),
endocarp (shell) and testa enveloping the mature endosperm (kernel) which,
importantly, has a central cavity (air space) containing residual liquid
endosperm (water). Figure 1A.2 gives a diagrammatic representation of
mature coconut fruit and its cross section. The large size and heavy weight of
the seed nut prevent dissemination by animals or birds but the fibrous husk
and the air space give it the necessary buoyancy for dispersal by floating. The
fruit takes ∼11 to14 months to develop after the receptive female flower is
successfully pollinated and before the growing point of the embryo penetrates
the germ pore (Harries, 2012).
1A.2. Brief history
Coconuts have been featured in the Hindu epic stories of the Ramayana and
Mahabharata (Menon and Pandalai, 1958). Early Sanskrit writings from the
4th century B.C as well as Tamil literature dating from the 1st-4th century AD
mention the coconut tree. The fruit has a special mention in the Mahavamsa
texts of Sri Lanka too, dating back to the 1st century B.C. The coconut was
mentioned by an Egyptian monk named Cosmos Indicopleusters in 545 A.D.
when he visited India and Ceylon. Cosmos describes the coconut as ‘the
great nut of India’ in his “Topographia Christiana”. The first detailed
description of the palm in western literature was provided by the Italian
explorer Ludovico di Varthe in his “Itinerio” of 1510 (Grimwood et al., 1975).
A native of the old world tropics, coconut’s domestication history and its
population genetic structure relate to human dispersal patterns. Two
geographical origins of coconut cultivation: islands of Southeast Asia and
3
southern margins of the Indian subcontinent have been proposed (Gunn et
al., 2011). More than 2000 years ago, people took the coconut with them
across the Indian Ocean to Madagascar, from where it journeyed on to East
Africa. In more recent times, Portuguese mariners, beginning with Vasco da
Gama in 1498, took the coconut from India and East Africa to the tropical
eastern Atlantic. From the Portuguese stronghold on the Cape Verde Islands
(off the coast of Senegal in West Africa), coconuts were taken in two
directions. Westwards, they were a source of food and drink on slave-trading
ships bound for Cuba and other islands, with those fruits remaining on arrival
being planted in the New World as a foundation food source. Eastwards, they
were dispersed from the Cape Verde Islands to the coast of West Africa, from
Senegal all the way to Angola. It was then dispersed to the islands of the
Caribbean, on the Caribbean coast of Mexico and Central and South America,
and along the coast of West Africa (Foale, 2003). It thereby became, and it
remains, the most widespread and widely used palm in the world.
1A.3. Global and national scenario
Coconut is grown in more than 93 countries around the world in an area of
about 12.17 million hectares, producing more than 60 million tonnes of
coconut annually. It provides food security and livelihood opportunities to
more than 20 million people around globe. India, Indonesia, Brazil,
Philippines, Thailand and Sri Lanka are the major coconut growing countries,
contributing to 78% of world production. India fares better than many other
countries with respect to production and productivity; and therefore, it enjoys a
comparative advantage (Lathika and Kumar, 2009). Table 1A.1 gives a list of
the top 5 coconut producing countries in world with respect to production and
4
percentage of world’s total coconut production. The coconut palm provides a
substantial export income for many tropical countries, as well as food and
drink for local consumption besides fuel and shelter.
The Asian and Pacific Coconut Community (APCC) is an intergovernmental
organization established in 1969 under the aegis of the United Nations
Economic and Social Commission for Asia and the Pacific (UN-ESCAP). The
APCC has 18 coconut producing member countries accounting for over 90%
of world coconut production and exports of coconut products. The APCC
member countries include: Federated States of Micronesia, Fiji, India,
Indonesia, Kiribati, Malaysia, Marshall Islands, Papua New Guinea,
Philippines, Samoa, Solomon Islands, Sri Lanka, Thailand, Tonga, Vanuatu,
and Vietnam. Jamaica and Kenya are associate member countries of the
APCC.
India is bestowed with most congenial agro-climatic conditions, diverse soil
types and abundant water resources required for coconut cultivation. The
statistics released by the Horticulture Division of Ministry of Agriculture, India
was in Metric tonnes (MT) and the production figure was 14 million MT which
in terms of whole nuts is equivalent to 21892 million nuts for the year 2011-12.
In India, there is a distinct difference in pattern of distribution of coconut. The
four southern states; Kerala, Karnataka, Tamil Nadu and Andhra Pradesh are
the main coconut growing areas in the country which together account for
90% of area under coconut cultivation and 93% in coconut production. Major
portion of coconut comes from the West Coast comprising of Kerala, Goa,
Karnataka and Maharashtra followed by the East Coast of Andhra Pradesh,
Orissa, Tamil Nadu and Pondicherry. The Islands of Andaman & Nicobar,
5
Lakshadweep and the coastal regions of Gujarat are the other traditional
coconut areas. In non-traditional states like Assam, Tripura, Nagaland,
Manipur, Mizoram, Meghalaya and Arunachal Pradesh also coconut
cultivation has gained momentum.
Table 1A.2 gives state wise distribution of coconut in the year 2011-12. Kerala
ranks first in coconut production but the growth in real estate, speedier
urbanization and faster substitution of coconut area for more remunerative
crops like rubber has resulted in decelerating growth in area under coconut.
Karnataka and Tamil Nadu, together, account for more than half of the
country’s production. About 95 per cent of the edible copra produced in the
country is Karnataka’s share. In Tamil Nadu, coconut cultivation and allied
industries have now become the main source of livelihood and employment
security for a large portion of the population in the state. Coconut is
extensively grown in three union territories of India, namely, Andaman &
Nicobar Islands, Lakshadweep and Pondicherry. Coconut in Lakshadweep is
cultivated using organic farming methods and this small island occupies the
number one position in the country in terms of productivity of coconut. There
has been perceptible increase in area under coconut cultivation in India since
the last six decades. The formation of Coconut Development Board (CDB)
with subsequent formation of coconut mission and its field level network in the
length and breadth of the country was instrumental for the expansion of the
crop nationwide giving a national image to the crop. Besides Coconut
Development Board, State department of Agriculture, Horticulture, State
Agricultural Universities, Research Institutes and other related organizations
6
in government and private sector contribute to the overall growth of Indian
coconut sector (Gopalakrishnan, 2013).
Though India has become the global leader in coconut production, it has not
yet achieved much in the diversification of the produce. Coconut processing is
confined only to copra production, oil extraction, production of desiccated
coconut and manufacture of coir and coir products. About 60% of coconut is
used for edible and religious purposes, 35% as milling copra for oil extraction,
approximately 3.5% for tender coconut water and the remaining processed as
desiccated coconut (NIIR Board of Consultants and Engineers, 2006). Other
countries like the Philippines, Indonesia and Vietnam have been adding value
to
this
agricultural
product
tremendously
using
the
state-of-the-art
technologies in the food processing industry. Failure of the Indian coconut
industry to diversify from its traditional sector is the main reason attributed to
the slow pace of development of coconut industry in India. Traditionally,
coconut was grown on a large scale for the production of edible oil. It served
as an ingredient for various industrial applications too. The changed food
habits and availability of other cheaper edible oils both in the edible and
industrial sectors have resulted in a drastic decline in the use of coconut oil in
these areas. During the last few years, on account of heavy imports of
cheaper vegetable oil, especially of the Palmolein, the price of coconut oil has
been put low despite the large-scale price support operations undertaken. The
diversification of coconut derived products and value addition could only help
the coconut growers in getting remunerative returns for the produce. Drastic
change in this situation is the need of the hour and can be achieved through
processing and export of diverse coconut products.
7
Table 1A.1: Top five coconut producing countries in 2013.
Rank Country
Coconut production
(tonnes)
Percentage of world’s
total coconut
production* (%)
1
Indonesia
18,300,000
29.5
2
Philippines
15,353,200
24.8
3
India
11,930,000
19.3
4
Brazil
2,820,468
4.5
5
Sri Lanka
2,200,000
3.6
* World production of coconut in 2013 was 61,965,165 tonnes
Compiled from http://faostat.fao.org
8
Table 1A.2: All India estimates of area under cultivation, production and
productivity of coconut during 2011-12
Sl no.
State /Union
Territory
Area
Production
Productivity
('000 Hectares)
(000 metric
ton)*
(Kilogram/ha)
1
Andaman and
Nicobar Islands
21.80
72.30
5184
2
Andhra
Pradesh
142.00
1270.00
13976
3
Assam
18.80
101.00
8397
4
Chhattisgarh
0.80
6.30
12309
5
Goa
25.70
88.70
5394
6
Gujarat
20.90
217.90
16296
7
Karnataka
506.80
3770.00
11627
8
Kerala
766.00
3973.00
8109
9
Lakshadweep
2.70
40.00
23156
10
Maharashtra
21.00
120.00
8931
11
Nagaland
0.90
0.30
521
12
Orissa
53.90
258.00
7482
13
Puducherry
2.10
20.00
14886
14
Tamil Nadu
420.70
3692.00
13717
15
Tripura
5.90
8.60
2278
16
West Bengal
29.10
367.50
19739
2039.10
14006.50
10736
All India
Source: Advisor, Horticulture Division, Ministry of Agriculture, Govt. of India.
(http://coconutboard.nic.in/stat)
* 1563 nuts - 1 metric ton
9
Figure 1A.1: The range of the natural habitat of the coconut palm tree delineated by the red line.
Source: http://en.wikipedia.org/wiki/Coconut
10
Figure 1A.2: Diagrammatic representation of mature coconut fruit and its
cross section.
11
Chapter 1B
Coconut Products
and Processing
1B.1. Coconut products
There is a saying, “He who plants a coconut tree, plants food and drink,
vessels and clothing, a habitation for himself and a heritage for his children”
(Pooja, 2010). A plethora of information is available about coconut products
and processing (Dendy and Grimwood, 1972; Grimwood et al., 1975;
Hazelman, 1997; NIIR Board of Consultants and Engineers, 2006; Philippine
Coconut Authority, 1997; United Nations Industrial Development Organization
and Ranasinghe, 1980; Woodroof, 1979). The coconut tree is of 100% utility.
The roots can be used for extracting dye stuff besides medicinal purposes.
The trunk yields handy and durable wood which can be used to make lumber,
various pieces of furniture, paper pulp and art or show pieces. The leaves
produce good quality of paper pulp and used for making brooms, hats, mats,
fruit trays, hand fans, midrib decors, lamp shades, bags and often used also
as roof materials, creating fences and kindling fires. Coconut inflorescence,
when cut, yields a liquid called Neera. Palm sugar or jaggery is produced by
carefully evaporating this liquid in open pots. Neera ferments, usually
spontaneously, to give palm wine or toddy which can be distilled to yield liquor
known as arrack (Grimwood et al., 1975).
The coconut (fruit) itself has numerous uses. The liquid endosperm in the
young and fresh coconut makes a refreshing natural beverage. There has
been increasing scientific evidence that supports the role of coconut water in
health and medicinal applications. Coconut water is used as a growth
supplement in plant tissue culture/micropropagation. The wide applications of
coconut water can be justified by its unique chemical composition of minerals,
vitamins, amino acids, phytohormones and sugars (Yong et al., 2009). It was
12
shown that this sterile liquid can even be used as a short-term intravenous
hydration fluid (Campbell-Falck et al., 2000). The thin coconut solid
endosperm (soft, jelly-like) of young coconut can be consumed as such or
used in culinary especially desserts. The energy-rich kernel of mature coconut
is an indispensable ingredient in most of the tropical cuisine. It is a good
source of oil, fibre and protein, and acts as a natural laxative. Coconut meat
can be processed to yield coconut milk, copra, oil and many other commercial
products which are discussed extensively in section 1B.2.
The hard shell, or endocarp, is used as fuel, food packaging material (icecream cups) and ornaments. A fine grade of charcoal can be produced which
can be used as fuel or for purposes such as ironing and smokeless fires in
restaurants. Shells can be also for preparation of fine grade activated carbon.
The fibrous husk contains an important fibre, commercially known as coir.
Coir is widely used in making mats, ropes, nets and other artefacts. Coir dust,
the fluffy particles obtained during separation of coir fibres from husk, can be
used as filler in soil to increase its moisture retention and as an insulating
material owing to its low thermal conductivity (Grimwood et al., 1975).
1B.2. Coconut processing
Coconut products have experienced astonishing growth globally over the past
several years. A wide range of coconut products are internationally traded.
There are more than 50 unprocessed, semiprocessed or processed coconut
products entering the international markets in small and big quantities. The
major products exported from coconut producing countries are copra and
coconut oil. Other exports which have a significant volume are desiccated
coconut, copra meal, cocochemicals (fatty acids, fatty alcohols, methyl
13
ethers), shell charcoal and activated carbon, fibre products, coconut cream,
milk, powder and nata de coco. Return on growth of the coconut products’
industry depends on how coconuts are processed and handled from the farm
to packaged goods. This section deals extensively with processing of
commercially available edible coconut products.
1B.2.1. Copra
Copra is the dried endosperm (nutritive tissue) of the coconut. More than 50
percent of the world’s coconut produce is processed into copra. It can be
broadly classified as edible or milling types. Edible grade of copra is
consumed as a dry fruit while milling copra is used to expel oil. The quality
parameters of copra for grading for different uses are specified in IndianStandard, IS: 6220-1971, which prescribes the methods of grading and the
requirements of copra for extraction of oil and for table use, together with
methods of sampling and tests. The 3 types of copra are defined as: type 1
(grades 1, 2 and 3), i.e. ball copra for table purpose; type 2 (grades 1 and 2),
i.e. cup copra for table purpose and type 3 (grades 1, 2 and 3), i.e. milling
copra for oil extraction.
Edible copra constitutes a very small percentage of the total production but
there could be better prospects for export market owing to the increasing
demand for edible copra by people living in the colder climatic regions. Edible
copra is of two different kinds namely, cup copra and ball copra. Cup copra is
usually processed in the copra kiln using fully-matured coconuts as raw
material in which coconuts are split-opened into two halves and loaded onto
the copra bed after a pre-drying (solar) in a cemented open yard for six to
seven hours. Although pre-drying of the coconut halves in an open yard
14
contributes to the fuel saving, it increases the chances of microbial
contamination in the end product. There are concerns with regard to the
deposition of smoke and lack of uniformity in the dehydration in the kiln drying
process which eventually affect the quality of the edible copra in terms of
discoloration, under drying, scorching or case-hardening. Ball copra, in
essence, is a substance formed within a fully matured whole nut due to
natural dehydration of coconut water. The fully mature (10-12 months),
unhusked nuts are stored for many months during which the coconut water
slowly gets absorbed and the kernel dries out. The dried kernel slowly
detaches from the coconut shell leading the formation of ball copra. This
stage can be well-recognized with a sound inside the cavity upon shaking. At
this stage, nut is dehusked and the shell is carefully removed to separate the
whole dry kernel. The ball copra has a soft texture and oily and sweet taste.
With increasing use of technology, ball copra formation could be expedited
through a method of kiln drying, where the time duration for ball copra
formation could be reduced from seven months to about two months
(Marikkar et al., 2009).
Coconut is one of the most widely used oil seed containing about 35% fat and
50% moisture (wet basis). Moisture content of coconut is required to be
reduced to less than 7% by drying to reduce the weight, prevent
microbiological deterioration and increase oil content before expelling of oil.
Traditional methods include solar drying, smoke drying and drying using kiln.
Copra manufacture solely by solar drying is effective only in regions with long
periods of sunny clear skies, high mid-day temperatures (30–35°C in the
shade) and low humidity air (60–70% RH). Solar drying involves spreading of
15
split coconuts on mats, cement floors, roof tops or even on soil along the
roadsides so as to expose to solar intensity until the completion of drying.
Exposure to direct sun light leads to heating of coconut pieces without
regulation which destroys colour, vitamins and flavour giving rise to low quality
produce. Solar drying also suffers from high product losses due to inadequate
drying, fungal growth, encroachment of insects, birds and rodents. Smoke
drying or curing involves drying of coconuts over open fire where the resultant
combustion gases come in contact with coconut meat. It is a very fast and
efficient dehydrating method but as smoke comes in direct contact with the
coconut, there is formation of polycyclic aromatic hydrocarbons and increase
in acid content, yielding poor quality of copra. Kiln drying involves drying using
commercially produced dryers or Kilns. The main components of the kiln are
drying chamber, roofing, grill, heat spreader, fire container and fuel tunnel.
The kilns used to dry coconut kernels vary from country to country. The
quality of the copra produced varies widely depending on the type and
operational conditions of the kilns. Usually a combination of preliminary solar
drying followed by kiln drying is used. Recently, a biomass fired drier that
yields high quality copra was designed, fabricated and tested for drying
coconut (Swain, 2013).
Although copra is not considered as a very high value product and application
of sophisticated dryers may not be appropriate, efforts have been made to
design and develop solar tunnel dryer (Kulanthaisami et al., 2009) and forced
convection solar dryer (Mohanraj and Chandrasekar, 2008).
16
1B.2.2. Coconut oil
Coconut oil is an edible oil that has been consumed in tropical countries for
thousands of years and currently finds various applications in food, medicine,
and industry. It has a long shelf life and a melting point of about 76 °F (~24°C)
(Gopala Krishna et al., 2010). A negative campaign against saturated fats in
general, and the tropical oils in particular, led to abandoning coconut oil
manufacture and consumption to a large extent in the past few decades. With
recent peer-reviewed research (Table 1B.1) as well as publishing coconut oil
testimonials’ (showing how coconut oil has changed peoples’ lives), coconut
oil has gained popularity and reputation as one of the healthiest oils with
versatile health benefits. The nutritional value of coconut oil is presented in
Table 1B.2. Industrial applications of coconut oil involve utilization as
feedstock for biodiesel to be used as a diesel engine fuel (Kumar et al., 2010),
engine lubricant (Jayadas and Nair, 2006) and as transformer oil
(Abeysundara et al., 2001).
Different types of coconut oil (edible) are available, namely, virgin coconut oil
from wet coconuts (unrefined grade); coconut oil from copra (refined/unrefined
grades); and coconut oil by solvent extraction method (refined, from coconut
expeller cake). Coconut oil is obtained through either "dry" or "wet"
processing. In dry processing, oil is expelled from copra by pressing (using
expellers) or by solvent extraction from spent cakes. Commercially, oil from
copra is expelled using rotary ghanis, hydraulic presses or expellers. This
"crude" coconut oil may not be suitable for direct consumption as it may
contain contaminants and must be refined with further heating and filtering.
Refined, bleached, and deodorized (RBD) coconut oil is widely available and
17
used for cooking, commercial food processing, and cosmetic, industrial, and
pharmaceutical purposes. But it lacks the typical coconut oil aroma and has a
bland taste due to the refining processes. RBD coconut oil can be processed
further into partially or fully hydrogenated oil to increase its melting point (upto
40C). Wet processing involves extraction of coconut oil from fresh mature
coconut rather than dried copra. When oil is extracted without employing heat,
shear, chemicals or refining it is known as virgin coconut oil. Different
methods, quality of oil, advantages and limitations are described in Table
1B.3. Virgin coconut oil is claimed to have more health benefits compared to
coconut oil expelled from copra (Nevin and Rajamohan, 2006).
1B.2.3. Desiccated coconut
Desiccated coconut, also known as coconut powder, is the dry form of grated
fresh coconut. It has become a mass consumption item due to its availability
round the year, long shelf life, reduction in wastage, convenient to transport
and freedom to the consumers to buy the required quantity. Desiccated
coconut has a great export value and its main consumers are confectionary
and biscuit industry. The manufacturing process is simple and wellestablished. Fully grown and matured coconuts of around one year are stored
with husk for a few days to facilitate absorption of mature coconut water into
the kernel. After de-husking, their shells are removed and the testa is
scrapped off (known as paring), followed by washing and disintegration. The
grating is then tray dried at about 70-80C until moisture content reduces to
~3%. The dry powder is then passed through vibratory screen with different
mesh sizes and packaged. Desiccated coconut is available in different grades
– fine, medium and coarse, as well as fancy cuts including threads, strips,
18
chips, slices and shreds (Grimwood et al., 1975). On an average, processing
of 100 coconuts gives around 12-13 kgs of desiccated coconut. The nutritional
value of desiccated coconut is presented in Table 1B.2.
1B.2.4. Coconut milk and related products
Coconut milk is a generic term for the aqueous emulsion expelled from wet
solid coconut endosperm and it plays an important role in the cuisines of
South East Asia as well as other parts of the world. It is a rich source of fat,
carbohydrates and minerals (Table 1B.2). In home preparations, coconut milk
is squeezed by hand from the freshly grated coconut (wrapped within a
cheese cloth). This process is usually repeated twice or thrice by adding water
at room temperature, each time obtaining a more dilute milk. The liquid
emulsions expelled from the wet coconut endosperm are classified
commercially into (1) concentrated coconut cream; (2) coconut cream
concentrate (undiluted coconut milk); (3) coconut cream; (4) coconut milk and
(5) light coconut milk based on minimum coconut fat and non-fat solids, and
maximum water content (Seow and Gwee, 1997). The production of coconut
milk begins with deshelling and paring of fully mature coconuts. It is
recommended to wash the meat in water containing 100 ppm H2O2, followed
by blanching at 80C for 10 min to reduce the initial microbial load and to
inactivate
lipase
before
disintegration/grating
using
a
hammer
mill
(Arumughan et al., 1993). After disintegration, the coconut meat is pressed
using a continuous screw press with or without addition of water to give
coconut milk. This may be then filtered or centrifuged at low speed and
homogenised prior to packaging in cans and sterilized in retort (Chiewchan et
al., 2006). Most coconut milk processed in this manner and sold commercially
19
in cans will naturally separate into aqueous and cream phases during storage
and transportation. The two phases can easily be mixed back together by
stirring or shaking the can. This phase separation can be retarded by using
emulsifiers and stabilizers such a polyoxyethylene sorbitan monostearate,
guar gum, xanthan gum, gellan gum and sodium carboxymethyl cellulose.
Sodium benzoate is usually used as a preservative. Coconut milk can be
cooled to sludge, canned and frozen to retain its flavour and freshness for
over a year when stored at -23C (Grimwood et al., 1975).
Spray dried coconut milk powder is now available in convenient and ready to
use packs with same freshness of a fresh coconut milk. This can be used on
reconstitution with water in place of fresh coconut milk for food
preparations/beverages in households and food industries. Its manufacturing
process involves homogenizing coconut milk and addition of maltodextrin,
sodium caseinate and other additives. This mixture is then spray dried into a
fine powder using a spray drier. The product can be packaged in various sizes
as per customer requirement. By decreasing water content and water activity,
spray dried coconut milk powder ensures microbiological stability, avoids the
risk of chemical and biological degradations, reduces the storage and
transport costs and finally obtain a product with specific properties like
instantaneous solubility. Council of Scientific and Industrial Research - Central
Food Technological Research Institute (CSIR-CFTRI), Mysore with the
financial assistance of the Coconut Development Board has developed the
technology for spray dried coconut milk powder which was made available to
entrepreneurs. Spray dried coconut milk powder is produced on a commercial
scale in the Philippines, Indonesia, Malaysia, Thailand and India. The major
20
markets for coconut milk and coconut milk powder are European countries;
like United Kingdom, Netherlands, Germany, France; USA, Mexico, Canada,
UAE, Australia, Japan, Korea, Malaysia and South Africa (Muralidharan and
Jayashree, 2011)
1B.2.5. Tender coconut water
The tender coconut water, technically the liquid endosperm present in young
green coconut (7-8 months old), is the most nutritious wholesome beverage
that the nature has provided to mankind. Tender coconut water is often sold
by street vendors who cut the tender coconut open in front of customers in
tropical countries. Coconut water can be now packaged in cans, tetra packs
or plastic bottles (sometimes with coconut pulp or coconut jelly included) with
or without carbonation. After the tender coconuts are harvested, they are
thoroughly water washed, then sanitized by transferring to a 1% bleach
solution for at least 15 minutes. The nuts are cut and the coconut water is
immediately filtered through a coarse filter to remove solids and particulates.
The water is then transferred to a sterile refrigerated tank and cooled to 4-6C
to avoid fermentation and enzymatic deterioration during further processing. A
clarifying resin such as polyvinylpolypyrrolidone (PVPP) is added to reduce
the level of polyphenols and tannins and to improve the stability of the final
product. The resin is then removed by a coarse filtration, following which the
coconut water is transferred to a pressurized holding tank. Nitrogen gas is
then used to push the coconut water through sterile microfilters into a sterile
holding tank. The sterile coconut water is then aseptically bottled (Rolle,
2007). The Coconut Development Board in collaboration with the Defence
Food Research Laboratory (DFRL), Mysore has developed a technology for
21
preservation and packing of tender coconut water in pouches and aluminium
cans with retention of its flavour for a period of three months under ambient
conditions and six months under refrigerated conditions. In Thailand, young
coconuts are trimmed, treated and packaged with opener, straw and spoon.
These are commercially produced and marketed (even exported to countries
like Australia, Europe, Japan, USA, Taiwan, Hong Kong etc.). The shelf life of
the processed young coconut is 45 days at 3-6C or 3 weeks at 7–10C
(Muralidharan and Jayashree, 2011).
Tender coconut water serves as a mineral drink with therapeutic properties
that help in regaining the vitality of the human body. Coconut water has
recently been popular among athletes, health freaks and urbanites in many
developed countries due to its high potassium and mineral content (Table
1B.2). Soft drink giants like Coca Cola and PepsiCo have acquired top two
brands of tender coconut water, Zico and O.N.E, respectively. United
Kingdom, Netherlands, Canada, Mexico, UAE, Japan, Korea and Australia
are the major importers of tender coconut water.
Tender coconut water contains only 3-6% solids and the remaining is water.
Removal of the water, while preserving the nutrients, aids in transporting the
goodness of tender coconut water across the world. This is achieved by either
spray drying or freeze dying tender coconut water with or without additives.
This coconut water powder is reconstitutable in water to make a hydrating
drink or can be added in other recipes like smoothies and desserts.
1B.2.6. Mature coconut water
As the coconut matures, the solid endosperm thickens while the amount of
liquid endosperm reduces. At the age of 10-12 months, when the coconut is
22
cracked open, this sweet liquid can be collected and consumed directly as it is
sterile and contains sugars and vitamins. Mature coconut water is a major byproduct of the copra and desiccated coconut industry, which often causes
disposal problems. It is generally fed to pigs and cattle when fresh but usually
goes to waste. It can be collected and used for different applications such as
growth media for micro-organisms and plant tissue culture (Prades et al.,
2012). Mature coconut water is also used for the manufacture of Nata-decoco and vinegar.
1B.2.7. Other products
A tremendous scope exists for use of coconut in a variety of food products.
The development of cottage industries to produce such products is
recommended to increase incomes of coconut growers.
One such product is Nata de coco, which is a chewy, translucent, jelly-like
foodstuff produced by the fermentation of coconut water. Originating in the
Philippines, Nata de coco is most commonly sweetened as a candy or
dessert. Nata-de-coco is produced from filtered coconut water to which glacial
acetic acid and sugar are added in specific quantities. The mixture is boiled
for ten minutes and cooled. A culture solution is added and allowed to ferment
for about three weeks. The Acetobacter xylinum bacteria produce cellulosic
jelly substance on the surface of this coconut water. This jelly, or Nata-decoco, is harvested and washed to eliminate traces of acid and diced into
cubes. These cubes are boiled in flavoured sugar solution and packaged in
glass jars or retortable pouches, sterilized and sealed (Lusas et al., 1989).
Nata de coco is regarded for its high dietary fibre, and its low fat and zero
cholesterol content.
23
Coconut vinegar is produced with matured coconut water by addition of sugar
to increase its sugar concentration to 15%. The solution undergoes
fermentation for about five days in the presence of Saccharomyces cerevisiae
(yeast). The clear liquid from the alcoholic fermentation is inoculated with 10%
vinegar containing Acetobacter bacteria. The acetic acid fermentation takes
about 1 month. The vinegar is then filtered, sterilised and bottled (Steinkraus,
1995).
Value added products like mature coconut-water concentrate (i.e. coconut
honey), tender coconut beverage (i.e. coconut lassi), coconut whey protein
from aqueous extract after the recovery of coconut milk, coconut spread
based on mature coconut-water concentrate and dietary fiber, coconut soufflé
and coconut chutney have been developed at CSIR-Central Food
Technological Research Institute, Mysore with the financial support of
Coconut Development Board, India (Raghavarao et al., 2011). Numerous
other traditional and new processed foods containing coconut are being
prepared and tested for their acceptability, quality and potential for
commercial manufacture. These include cakes containing 10-40% coconut
flour, coconut candy, “tokua”, soya curd containing 50% coconut milk and
50% soya milk, soya tofu containing coconut cream, “coco spread”, containing
coconut milk, brown sugar, citric acid and legume flour, “tahu”, a snack based
on coconut and soya milk, etc. (Salunkhe and Kadam, 1995).
Thus it is rightly said "The coconut palm is alone sufficient to build, rig and
freight a ship with bread, wine, water, oil, vinegar, sugar and other
commodities".
24
Table 1B.1: Health benefits of coconut oil
Sl. No.
1.
Aspect
Details
Comments
Principal oil
components
Fatty acid composition:
~50% lauric acid, 70%
medium-chain fatty acids
(MCFAs).
Highest proportion of
medium-chain
components of any oil.
High melting point; solid
below 24°C.
Most stable of all the
92% saturated fatty acids cooking oils. Saturated
(Gopala Krishna et al., fats have no double
2010).
bonds at risk of oxidation
therefore
giving
outstanding stability in
storage and use.
2.
Uptake path
in human
body
MCFAs
are
directly
absorbed
from
the
intestine and sent straight
to the liver to be rapidly
metabolized for energy
production and do not
participate
in
the
biosynthesis and transport
of cholesterol (DebMandal
and Mandal, 2011).
All
long-chain
fats
(saturated or not) are
carried directly to lipid
deposits,
accumulating
as body fat.
3.
Reduces
cholesterol
and
triglyceride
levels
Virgin coconut oil has
antioxidant activities and
does not adversely alter
serum lipid levels. Sperm
count, motility and serum
testosterone levels are
also reported to increase.
These antioxidants offer
protective
effects
on
alcohol-induced oxidative
stress in rats (Dosumu et
al., 2012).
Consumption of virgin
coconut oil reduces total
cholesterol, triglycerides,
phospholipids, LDL, and
VLDL cholesterol levels
and
increased
HDL
cholesterol in serum and
tissues
(Nevin
and
Rajamohan,
2004).
Erroneous
perception
that coconut oil raises
cholesterol
due
to
selective
tests
with
flawed diets.
4.
Slows the
progression
of
Alzheimer’s
disease
Medium chain triglycerides
from coconut oil given to
Alzheimer’s patients led to
significant
increase
in
levels of the ketone body
beta-hydroxybutyrate
(beta-OHB). Higher ketone
Major advantage: the
saturated fat of coconut
oil provides is its ability to
provide the brain with an
alternate
source
of
energy in ketones.
25
values were associated
with greater improvement
in paragraph recall with
MCT treatment relative to
placebo across all subjects
(Nafar and Mearow, 2014;
Reger et al., 2004).
5.
Reduces
obesity
Dietary
supplementation
with coconut oil leads to
increase in High Density
Lipid (HDL) and lowers
Low Density Lipid (LDL):
HDL ratio (Assunção et al.,
2009).
Coconut oil does not
cause dyslipidemia and
seems to promote a
reduction in abdominal
obesity.
6.
Antibiotic
effect of
mediumchain fatty
acids on
pathogens
Derivatives of lauric and
capric
oils
suppress
bacterial, fungal and viral
pathogens of humans,
including HIV (German and
Dillard, 2004).
Coconut oil is widely
used in treating skin
wounds. HIV suppression
is promising, and study
continues (Dayrit, 2000)
26
Table 1B.2: Nutritional value (per 100 g) of coconut oil, desiccated coconut,
coconut milk and coconut water.
Sl.
no
Nutrient
Coconut
oil
Desiccated
coconut
Coconut
milk
Coconut
water
1.
Water (g)
0.00
3.00
67.62
94.99
2.
Energy (kcal)
862
660
230
19
3.
Protein (g)
0.00
6.88
2.29
0.72
4.
Total lipid (fat) (g)
100.00
64.53
23.84
0.20
5.
Carbohydrate, by difference (g)
0.00
23.65
5.54
3.71
6.
Fiber, total dietary (g)
0.0
16.3
2.2
1.1
7.
Sugars, total (g)
0.00
7.35
3.34
2.61
8.
Calcium, Ca (mg)
0
26
16
24
9.
Iron, Fe (mg)
0.04
3.32
1.64
0.29
10. Magnesium, Mg (mg)
0
90
37
25
11. Phosphorus, P (mg)
0
206
100
20
12. Potassium, K (mg)
0
543
263
250
13. Sodium, Na (mg)
0
37
15
105
14. Zinc, Zn (mg)
0.00
2.01
0.67
0.10
15. Vitamin C, total ascorbic acid (mg)
0.0
1.5
2.8
2.4
16. Thiamin (mg)
0.000
0.060
0.026
0.030
17. Riboflavin (mg)
0.000
0.100
0.000
0.057
18. Niacin (mg)
0.000
0.603
0.760
0.080
19. Vitamin B-6 (mg)
0.000
0.300
0.033
0.032
20. Folate, DFE (µg)
0
9
16
3
21. Vitamin B-12 (µg)
0.00
0.00
0.00
0.00
22. Vitamin A, RAE (µg)
0
0
0
0
23. Vitamin A, IU (IU)
0
0
0
0
24. Vitamin E (alpha-tocopherol) (mg)
0.09
0.44
0.15
0.00
25. Vitamin D (D2 + D3) (µg)
0.0
0.0
0.0
0.0
0
0
0
0
27. Vitamin K (phylloquinone) (µg)
0.5
0.3
0.1
0.0
28. Fatty acids, total saturated (g)
86.500
57.218
21.140
0.176
29. Fatty acids, total monounsaturated (g)
5.800
2.745
1.014
0.008
30. Fatty acids, total polyunsaturated (g)
1.800
0.706
0.261
0.002
31. Cholesterol (mg)
0
0
0
0
32. Caffeine (mg)
0
0
0
0
26. Vitamin D (IU)
Source: Compiled from Agricultural Research Service, United States Department of
Agriculture, National Nutrient Database for Standard Reference, Release 26
(http://ndb.nal.usda.gov/ndb/foods)
27
Table 1B.3: Comparative analysis of different processes for producing VCO
Sl. No.
Type of
Process
Quality of Oil and Advantages
Recovery
Limitations
Fresh-dry processes
1.
High pressure
expeller method
FFA (Free Fatty
Acid): 0.05–0.08%
MC: 0.07–0.1%
Wet milling route Colour: water-clear
Oil recovery: 60 kg
Moisture
per 100 kg of dried
Content (MC) of milled kernel; 31 kg
dried kernel for
per 100 kg of fresh
extraction
milled
coconut
should be at 3kernel with testa
4%
(based on 50% initial
MC of fresh kernel)
Highest extraction
efficiency
2.
High pressure
expeller method
Desiccated
coconut route
MC of dried
kernel for
extraction
should be at 34%
3.
High pressure
expeller method
Grated nut route
MC of dried
kernel for
extraction
should be at 3–
4%
FFA: 0.05–0.08%
MC: 0.0–0.1%
Colour: water-clear
Oil recovery: 58 kg
per 100 kg of
desiccated coconut ;
30 kg/100 kg of fresh
pared, ground kernel
(based on 50% initial
MC of fresh kernel)
FFA: 0.05–0.08%
MC: 0.07–0.1%
Colour: water-white
Oil recovery: 30 kg
per 100 kg of fresh
grated kernel (based
on 50% initial MC of
kernel)
and
Produces
full-protein,
medium- fat coconut flakes
with testa as a co-product
which
can
be
further
processed into coconut flour
or sold as an aflatoxin-free
animal feed ingredient.
Long shelf-life of oil – 1 year
and above.
Uses mechanical type of
equipment to produce the
oil.
Applicable in a village scale
plant operation (5,000+
nuts/day).
Produces
full-protein,
medium-fat coconut flour
without testa as a coproduct.
Long shelf-life of oil – 1 year
and above.
Uses mechanical type of
equipment to produce the
oil.
More appropriate to be used
in tandem with an existing
desiccated
coconut
processing plant.
Produces
full-protein,
medium-fat coconut flour
without
testa
as
a
coproduct.
Long shelf-life of oil – 1 year
and above.
Uses mechanical type of
equipment to produce the
oil.
Applicable in a village scale
28
4.
Low pressure
expelling
method
MC of dried
kernel for
extraction
should be within
the range of 10–
12%.
5.
Centrifuge
method
MC of dried
kernel prior to
micropulverisation at
5%
FFA: 0.05–0.08%
MC: 0.1% and below
Colour – water-clear
Oil recovery - 60 kg
per 100 kg of dried
ground
kernel
without testa; 31 kg
per 100 kg of fresh
pared kernel (based
on 50% MC of fresh
kernel)
Second highest oil
extraction
efficiency.
plant operation (5,000+
nuts/day).
Uses manually operated
equipment to produce the
oil.
Produces
a
semi-dry
coconut residue that has to
be
further
dried
or
processed to have market
value.
Shelf-life of oil can be very
short if milled or grated
coconut kernel is not
properly prepared prior to oil
extraction. Oil drying is
recommended to ensure
long shelf-life.
Produces low-fat, high-fibre
coconut milk as a coproduct.
Long shelf-life of oil – 1 year
and above. Can also be
used
in
tandem
with
desiccated
coconut
processing.
High investment cost since it
uses
highly
specialised
equipment and is energy
intensive.
Very intense, fresh coconut
aroma.
FFA: 0.1%
MC:
0.14%
and
below if heating is
done long enough to
remove water in the
coconut milk
Colour - water-clear
to
pale
yellow
depending on the
heating process
Very low investment cost.
Can be produced on a home
scale
operation
using
ordinary kitchen utensils.
Produces a wet coconut
residue that has to be
further dried or processed to
have market value.
Produces
a
by-product
(proteinaceous
residue)
FFA: 0.1–0.2%
MC:
0.17%
and
below
Colour: water-clear
Oil recovery: 25 kg
per 100 kg of fresh
grated
coconut
kernel (based on
50% initial MC of
kernel)
Fresh-wet processes
6.
Modified kitchen
method
29
Oil recovery - 16.5
kg per 100 kg of
fresh grated coconut
kernel (based on
50% initial MC of
kernel)
which does not have
commercial
value
at
present.
Oil drying is recommended
to prolong shelf-life.
Hardest to control in getting
the correct colour and low
MC.
7.
Modified natural
fermentation
method
FFA: 0. 1%
MC:
0.12%
and
below
Colour - water-clear
Oil recovery - 34
litres per 100 litres of
coconut milk (about
19 kg oil per 100 kg
of
fresh
grated
kernel) (Based on
50% initial MC of
kernel)
Very low investment cost.
Lowest labour and energy
input.
Can be produced quickly on
a home scale operation
using
ordinary
kitchen
utensils or on small/medium
scale operation using semimechanised equipment.
Disposal of fermented skim
milk could be a big problem
if done on a medium scale
plant operation.
Oil produced has a faint
sour smell which can be
removed by ageing.
Produces premium and
class B grades of VCO.
Uses a lot of potable water.
8.
Fresh-wet
centrifuge
method (2phase
centrifuge)
FFA: 0.04–0.08%
MC: 0.1% and below
Colour: water-clear
Oil recovery: about
28 litres oil per 100
litres of coconut milk
(about 17 kg oil per
100 kg fresh grated
kernel) (Based on
50% initial MC of
kernel) Reported oil
recovery rate was
computed from the
information provided
Produces the best quality
coconut
oil
with
best
sensory attributes if done in
a two stage centrifuge
process.
Can only be applied in a
medium scale operation as
investment cost is very high.
Optimisation of the process
is still required to improve oil
recovery rate.
Current oil recovery rates
are much lower than the
modified
fermentation
30
by a VCO producer
using a 2-phase
centrifuge.
Oil
recovery rate using a
3-phase centrifuge
may be different.
9.
Bawalan-Masa
process
10.
CFTRI process
FFA - 0.05–0.08%
MC - 0.07–0.12%
Colour – water- clear
VCO from kernel Oil recovery - 17 kg
fibre residue left per 100 kg of wet
after expelling
residue
Coconut
coconut milk.
flour - 26.3 kg per
100 kg of wet
residue
Enzyme
assisted freshwet centrifuge
method
FFA- 0.12 %
MC- 0.21%
Colour – water- clear
Oil recovery – Upto
27 kg per 100 kg of
fresh grated coconut
kernel (based on
50% initial MC of
kernel)
process. Lowest extraction
efficiency.
Further
processing of the coconut
skim
milk
into
health
beverage and the sapal
generated into coconut flour
can improve profitability
Further recovery of high
value oil from residue
makes coconut milk/VCO
processing more profitable.
Long shelf-life of oil – 1 year
and above.
Produces low fat high fibre
coconut flour as a byproduct.
Requires mechanical type of
equipment to produce the
oil.
Production process has to
be attached or integrated to
an existing coconut milk
processing plant or a high
capacity VCO plant.
Maximises the income from
coconut kernel when used in
tandem with coconut milk
processing or the fresh-wet
centrifuge process of VCO
production.
Vitamin E content in oil is
high (6.2 mg/100ml).
Very
good
sensory
attributes with intense, fresh
coconut aroma.
Source: Updated and revised table from Bawalan (2011)
31
Chapter 1C
Biotechnological Processing for
Value Added Products
from Coconut
Biotechnology has played a vital role in different spheres of life. It is the use of
biological processes, organisms, or systems to manufacture products
intended to improve the quality of human life. It has made a significant impact
in health care (development of vaccines and other biologicals), agriculture
(development of hybrid plants), etc. as well as in food processing sector. The
advances in application of biotechnology in food processing mainly concerns
with the approaches such as strain improvement of microorganisms for the
production of fermented foods (like curd and soy sauce) and use of enzymes
for the manufacture of processed foods (like cheese and juices). It also has
helped in improving the edibility, texture and storage of the food. Various
amino acids, food-flavouring agents, food additives and preservatives are
derivatives obtained from processing of biomass of microbial, plant or animal
origin. A bioprocess involves biomass pretreatment, fermentation or
biocatalysis and finally downstream processing (Yang, 2011) or isolation from
natural
source
by
physical/chemical
methods
before
subjecting
to
downstream processing. It finds its application in oilseed processing and
refining, starch and protein processing, non-thermal food processing (eg.
filtration), fermentation, extraction techniques, enzymatic conversions, and
packaging.
In the coconut industry, bioprocessing is inevitable as the different products
obtained are a result of different unit operations such as drying, fermentation,
extraction,
etc.
Bioprocess
engineering
is
a
specialized
branch
of
biotechnology which involves design and development of equipment and
processes for the production of value added products. This technology has
revolutionised the scale at which coconut products can be manufactured
32
compared to traditional methods especially for oil, desiccated coconut and
copra production.
Fermentation is known to conserve properties of food for long term storage,
biotransformation and improvement in assimilation of nutrients. Products such
as coconut toddy, vinegar, Nata-de-coco and virgin coconut oil (fermentation
method) involves use of microorganisms for bioconversion using coconut as
raw material. Coconut pro-biotics can also be prepared from coconut water or
coconut milk using Kefir or Kombucha (symbiosis of lactic acid bacteria and
yeast) as starter culture (Tietze et al., 2006). With increasing demand for nondairy products and some noise on the World Wide Web about soy not being
healthy, coconut yoghurt has also been launched in the market (Aoyagi,
2013).
Enzymes are used in the food industry for achieving high product yields and
avoiding energy intensive unit operations with severe operational conditions.
Domínguez et al. (1994) reported that most extraction processes (mechanical
pressing and solvent extraction) suffer from major drawbacks with regard to
economic, environmental and safety aspects. The high temperatures and
solvents used cause undesirable side effects on the quality of the finished
product and the protein obtained is often denatured, thus limiting its use for
food and feed products (Johnson and Lusas, 1983). These problems could be
overcome by the aqueous processing of oil seeds. Simultaneous aqueous
processing and enzymatic treatment can favour the extraction of oil in
environmentally safe and economical manner, also yielding an edible protein
product. Lower operation temperature can be used, with consequent lower
energy requirements. In the case of coconut, aqueous enzymatic processing
33
is a possible alternative technology for the extraction of oil and the protein. A
number of workers have reported utilization of enzymes for extraction of
coconut oil. McGlone et al. (1986) reported an extraction method of coconut
oil based on the action of different enzymes like polygalacturonases, αamylase and proteases on a diluted coconut paste. About 80% yields were
obtained by this method with an added advantage of very low energy inputs.
Barrios et al. (1990) studied the effect of pectinase, α-amylase, proteases,
cellulases and - glucanases at different concentrations and temperatures on
extraction of coconut oil. This study on a laboratory as well as pilot scale
indicated higher yield of oil and considerably low capital investment but
suffers from drawbacks such as high cost of enzymes, requirement of fresh
water and treatment of wastewater prior to disposal. Rosenthal et al. (1996)
and Ricochon and Muniglia (2010) have comprehensively reviewed aqueous
and enzyme based processes and discussed related issues for edible oil
extraction. All studies indicate that different enzymes are required to degrade
different components of the structural cell wall (mannan, galactomannan and
cellulose) thus releasing oil from cells (Figure 1C.1). Enzymes also decrease
emulsion stability during coconut oil extraction, resulting in rapid oil
separation. Raghavendra and Raghavarao (2010) reported the effect of
different treatments like thermal, pH, chilling, enzyme treatments and
combination of enzyme treatment followed by chilling, thawing for the
destabilization of coconut milk emulsion to obtain virgin coconut oil. The
highest yield of 94.5% was observed in the coconut milk sample treated with
0.1% v/v of protease at 37°C followed by chilling and thawing to ambient
conditions. Proteins (which act as emulsifiers in coconut milk) are broken
34
down into smaller peptides by protease, decreasing their emulsifying ability.
This leads to aggregation of oil droplets, destabilization of the emulsion and
results in higher oil yields (Figure 1C.2).
35
Figure 1C.1: Effect of enzymatic treatment on oil seed cell structure
Source: Rosenthal et al. (1996)
36
Figure 1C.2: Effect of enzymatic treatment on coconut milk emulsion
37
Chapter 1D
Aim and Scope of
Present Work
In order to fullfill the objectives, methods for dehydration of fresh coconut and
copra gratings, an improved process for production of virgin coconut oil and
methods for value addition to the byproducts were developed. This thesis
consists of five chapters, of which chapter 1 contains general introduction
about coconut, coconut products and processing as well as biotechnological
processing for value added products from coconut.
Chapter 2 deals with process for production of coconut oil from fresh coconut
and copra gratings. The choice of dryer to dehydrate coconut gratings based
on product quality was made. Drying kinetics of coconut gratings was studied.
Effect of pretreatment of copra with enzymes on expelling of oil copra was
investigated.
Coconut milk is an oil-in-water emulsion that is expelled from fresh coconut. In
chapter 3, the first section consists of stabilization studies of coconut milk
using silica nanoparticles and comparison with other commercially used
stabilisers. In the second section, effect of different treatments (emzymatic,
pH and ultrasound) for destabilization of coconut milk for the production of
VCO was studied. An improved process for production of VCO was also
developed.
In chapter 4, value addition to coconut skim milk was attempted by
dehydration (drum drying, spray drying and freeze drying) and concentration
(ultrafiltration) in two sections. The effect of dehydration methods was studied
on functional properties and sensory quality of product. The process
parameters considered in ultrafiltration (UF) were standardized with respect to
transmembrane flux, protein retention and sugar removal.
38
Chapter 5 deals with production, characterization and storage studies of
coconut protein powder (CPP). Functional properties of CPP were evaluated
and compared to defatted soybean powder and cow skimmed milk powder.
Storage studies of CPP were carried out in order to estimate the shelf life of
the product. Sensory and instrumental analysis of CPP was carried out. A
pilot consumer acceptance test was carried out to rate the acceptability of
product.
39