CHAPTER-I
INTRODUCTION
Maize (Zea Mays) is known as corn in United States of
America and in certain others parts of the world. Corn continues
to be classified as one of the ‘coarse grains’. However none other
coarse grain provides the desired level of economic viability to the
processing units because of the unmatched high valued products
obtained from maize. Maize also hold an important place in the
food economy of India as it has great utility as food for the poorer
section of the population being cheaper than rice and wheat.
Maize, a kharif crop, is perhaps the only coarse grain in India
whose production and yield has shown a steady growth in the
past five years.
Maize is universal crop grown in the developed and
developing countries. India’s share in the world’s area is 4.5
percent (63.1 lakh tons) with 5 th place next to USA, China, Brazil
and Mexico. Andhra Pradesh has a share of 6.4 percent in the
area covered under crop in India with 10 percent share of the
country’s production and stands at 6 th rank (Anonymous 2000).
It is the third most important cereal crop of the world next to
wheat and paddy. Among all cereals, maize crop is 5 th largest in
1
area, 4th largest in output and 3 rd largest in the yield. In India
only 45-48 percent of maize produced is consumed by humans,
the rest is used in cattle and poultry feed and by the starch
industry. According to one estimate, the demand for maize for
human consumption, poultry feed, starch manufacture and other
uses is likely to go up from 107 lakh tones in 2000-01 to 186
lakh tones in 2011-12 while the production is expected to go upto
only 160 lakh tonnes (Singhal 2003).
Maize is one of the staple foods for the people of
Punjab, Uttar Pradesh and Rajasthan in India (Reddy et al 1991).
In USA and Europe, a large part of the maize produced is used as
livestock feed. The way in which maize is processed and
consumed varies greatly from country to country, maize flour and
maize meal being two of the most popular products. For maize
meal, whole maize is ground into granulated meal with range of
particle sizes from coarse to fine while maize flour is obtained
from milling the endosperm of the maize grain after the germ and
outer layers are removed. These products have replaced the
whole maize as important components in the diet in many parts
of the world. In India, maize is ground to wholemeal atta in small
power driven chakkis and is consumed in the form of roti/
2
chapatti. It is this form that maize is consumed in most parts of
northern and western India. Large scale milling of maize to
produce flour and suzi is carried out in few cities in Maharashtra,
Karnataka, Punjab and Haryana. Maize can be milled to variety
of products. The principal products of maize dry milling are grits,
meal and flour. It is also used in the form of porridges of various
forms, boiled or roasted green ears, breakfast food like corn
flakes and popcorn. Boiled or roasted green ears and popcorn are
especially consumed in USA and Europe (Anonymous 2000).
Nutritionally maize is quite similar to other cereal
grains. The proximate composition of dry maize is 11.0 g protein,
3.6 g fat, 1.5 g mineral and 2.7 g fiber per 100g of grains. Its
energy value is 342 Kcal quite similar to that of wheat or rice
Tender maize contains 4.7 g protein, 24.6 g carbohydrates and
only 9 mg of calcium (Gopalan et al 2004). Based on FAO/WHO
scoring pattern, lysine is the first limiting amino acid in maize,
followed by tryptophan and threonine (Eggum and Beames 1983).
Compared with other cereal grain proteins, the protein score for
maize is fairly low. As in other cereal grain proteins, glutamic
acid
is
major
amino
acid.
In
addition,
maize
protein
is
characterized by high content of leucine. About 50% of the
3
protein in the endosperm is constituted by zein, which lacks
lysine and tryptophan. Zein is also low in threonine, valine and
sulphur amino acids. Many efforts have been made to improve
biological utilization of protein in maize by genetic manipulation,
processing and also by fortification (FAO 1993).
Maize is one of the best sources of metabolizable
energy among the grains. The oil in maize contributes about 1012% of the total metabolizable energy provided by maize (Wright
1987). Compared with other food starches, maize starch is
hydrolyzed very rapidly by α-amylase (Gee and Johnson 1998)
and the carbohydrate of maize seem to be well digested by
human digestive enzymes. Maize bran has been of particular
interest because of its potential as a source of dietary fiber.
The concentration of minerals and trace elements in
maize is lower than in other cereals. A major proportion of
nutritionally important minerals as well as phytate is present in
the germ and the contents of minerals and phytate in maize
products is largely determined by the extent to which the germ is
retained. Maize, like other cereals is very low in calcium (Wright
1987).
4
Maize is deficient in number of essential nutrients.
Removal of bran and germ fractions merely enhance these
deficiencies. Maize consuming populations would be nutritionally
better off if the maize consumed had the lysine and tryptophan
genes of quality protein maize or if it were consumed with a
sufficient amount of protein foods such as legumes, milk,
soybeans, amaranth seeds and leaves. The protein of leafy
vegetables is considered to be of high biological value. Leafy
vegetables like mustard, spinach and fenugreek can supplement
the maize based diets thus making them nutritionally adequate.
Human
metabolic
studies
have
shown
that
replacement of part of maize in vegetarian diet by wheat brings
marked improvement in the overall nutritive value of cereal
mixture. The beneficial effects of corn and soy combination on
improvement of amino acid balance have long been recognized by
nutritionists. Proteins from yeast and soybean are equal to skim
milk in supplementing the proteins of milled maize meal. When
soy proteins form 60% of the total proteins of maize soya bean
mixture, the PER is raised from 1.6 to 2.9 (Chadha 1987).
Since cereals and millets are the cheapest and the
most widely available source of energy, this contribution to
5
energy intake is highest among the poor families and it is
decreasing with increasing income (Gopalan et al 2004). The
nutritional inadequacies of the maize are also well known,
supplementation with protein rich sources and preparation of
acceptable products would not only improve nutritional value of
maize but would also provide a variety. Roasted and steamed
maize grains, maize chapatti with sarson ka saag are popular and
commonly consumed among Punjabi families. However there are
limited products being prepared from maize flour and the
available information on nutritional value of different maize
products is scanty and is insufficient. Hence, the present study
was carried out with the following objective:1.
To develop nutritious recipes based on maize flour.
2.
To evaluate these recipes organoleptically.
3.
To determine the nutritional quality of developed recipes
6
CHAPTER-II
REVIEW OF LITERATURE
Maize is one of the basic staple food for large
population groups particularly in developing countries. It is
primarily consumed in the form of chapaties in India. Therefore,
there is great significance in the improvement of nutritive value
of maize to the ordinary consumer, who depend wholly or
partially for their daily requirement of protein, calorie and
minerals. On seeing, its low nutritional value with respect to
protein, many efforts have been made to improve the nutritive
value of maize. Available literature has been reviewed and
presented under the following headings:
1. Nutritive value of maize
2. Nutritional value of supplemented maize products
3. Sensory evaluation of maize products
4. Effect of processing on nutritive value of maize flour
1. Nutritive value of maize:
The chemical composition of wholemeal, three
semi-sifted flours and degermed maize was determined and the
nutritional value of the flours were investigated by Pederson and
Eggum (1983) in balance experiments with growing rats. Weight
7
gain of rats fed degermed maize was reduced to half of that of
rats fed wholemeal. True protein digestibility was high, but
protein
quality
fractions.
varied
widely
Supplementation
of
between
the
wholemeal
different
with
lysine
flour
and
tryptophan increased the biological value of the protein and the
weight gain considerably. The percentage of zinc absorbed from
degermed maize flour was high, but degermed maize has a very
low content of minerals and is highly deficient in lysine and
tryptophan.
Three maize varieties which differ in their
nutritional quality and endosperm texture were processed to
prepare semolina (sooji) and process-flour. In quality evaluation
tests; lysine and tryptophan content, biological value and true
digestibility were better in semolina and process- flour (Gupta et
al 1989).
Rye, wheat, barley, rice, maize and sorghum
were milled into more or less refined fractions, and the content
of various vitamins and tryptophan were determined by Hegedus
et al (1985). The lowest vitamin content was found in highly
refined rice, containing only about 5% of the folate and 10% of
the niacin present in brown rice. Maize had a low content of
8
tryptophan and the concentration was greatly reduced by
degerming. For the other cereal grains, milling had only a slight
effect on tryptophan concentrations.
Agama et al (2004) conducted a study on in vitro
starch digestibility changes during storage of maize flour
tortillas. A decrease in available starch content was observed
upon 48 hr cold storage (4°C), changes that were concomitant
with increased total resistant starch (RS) levels. Lower digestion
rate values were shown for the stored materials. The differences
found among the various tortilla samples may be due to
variations in processing conditions during commercial maize
flour preparation, and to the use of different maize varieties.
Gupta et al (1984) studied the chemical composition
of maize kernels and their products and observed that germ was
the richest source of fat, protein, ash and crude fiber.
According to Indian Agriculture Research Institute
report (1980), the nutritional quality of maize protein was poor
because of limiting concentration of two essential amino acid i.e.
lysine and tryptophan and high leucine content. The protein
content in maize varieties varied from 8.5 to 13.6 percent while
9
the average was about 10 percent lysine content varied from 1.7
to 3.2 percent while tryptophan from 0.35 to 0.5 percent.
Gupta et al (1987) observed that protein and starch
contents in Indian maize ranged from 9.85 to 12.91 percent and
64.33 to 70.57 percent, respectively while the ranges in values
of fat, ash and crude fiber contents were 4.33 to 5.89 percent,
1.35 to 1.92 percent and 2.18 to 2.91 percent, respectively. They
also reported that incorporation of opaque-2 gene in normal
maize
varieties
could
favourably
modify
the
amino
acid
composition of the endosperm primarily due to reduction in zein
fraction of protein which was largely deficient in lysine and
tryptophan.
Rehal (1997) reported that percent protein, fat and
starch in maize ranged from 9 to 11.30, 3.33 to 4.41 percent
and 56.65 to 60.97 percent, respectively.
A study was conducted by Turnlund et al (1990) in
healthy young women to measure and compare the availability
of iron from cereal based diets with and without milk by use of
in vivo and in vitro methods. The results suggested that in vivo
and in vitro effects differ and that the absorption of iron from
10
cereal based diet is neither enhanced nor inhibited by addition
of milk.
Mendoza
et
al
(1998)
evaluated
the
effect
of
genetically modified, low phytic acid maize on absorption of iron
from tortillas by using extrinsic tag method which was measured
as the incorporation of radio labelled iron into red blood cells of
14 nonanaemic men two weeks after intake. It was observed that
iron absorption was 49 percent greater in low phytic acid maize
than that from the wild type maize. It was concluded that
consumption of genetically modified, low phytic acid strains of
maize improved iron absorption in humans that consumed
maize based diets.
2. Nutritional value of supplemented maize products
Supplementation
of
maize
based
West
African
traditional weaning food with cowpea increased the lysine,
tryptophan and threonine content while the sulphur-amino
acids decreased with increasing levels of cowpea. The BV and
NPU of blends containing 30% pre-cooked cowpea increased
from 52 to 76% and 50 to 71%, respectively as compared to pure
maize porridge (Nti and Plahar 1995).
11
Yeudall et al (2005) evaluated the efficacy of a
community-based
micronutrient
dietary
intervention
inadequacies
in
to
reduce
high-phytate
risk
of
maize-based
Malawian diets. Intervention children had diets that were
significantly more diverse and have a higher quality than those
of controls. Median daily intakes of protein, calcium, zinc (total
and available), haem iron, vitamin B 12 and animal foods (grams
% of total energy) were higher (p≤0.05) whereas phytate intakes,
phytate/zinc and phytate/iron molar ratios were lower (p≤0.01)
in the intervention group.
A study on the effectiveness of a vitamin-fortified
maize meal to improve the nutritional status of 1–3 year old
malnourished African children was carried out by Faber (2005).
Sixty undernourished African children with height-for-age or
weight-for-age below the 5th percentile of the National Center
for Health Statistics' criteria were randomly assigned to an
experimental or control group. The children in the experimental
group had a significantly (P≤0.05) higher increase in body weight
than control children (4.6 kg vs. 2.0 kg). The change in serum
retinol showed a significant correlation with baseline retinol (P =
0.014), RBP (P = 0.007) and weight (P = 0.029), as well as with
12
changes in haemoglobin (P = 0.029). The study confirmed the
relationship between vitamin A and iron status. The results
suggest that fortification of maize meal would be an effective
strategy to address micronutrient deficiencies in small children
in South Africa.
The
proximate
composition,
acceptability
and
nutritional properties of akara produced from cowpeas and
white maize flour blends in the ratios 100:0 (Sample A, control),
85:15 (sample B), 75:25 (sample C), 65:35 (sample D), 50:50
(sample E), 40:60 (sample F), and 30:70 (sample G), respectively,
were investigated. Crude protein, fat and moisture contents of
the all-cowpea akara decreased to 15.8%, 16.5% and 17.5%,
respectively, when the level of maize flour in the blend increased
to 70%. Up to 35% maize flour in the blend produced acceptable
akara. There were no significant (p > 0.05) differences between
the values obtained for protein efficiency ratio, net protein ratio,
and apparent and true digestibilities of diet G and casein when
fed to rats, suggesting an improvement in the protein quality of
akara prepared from cowpea: maize (30:70 w/w) flour blend, but
at the expense of acceptability (Giami et al 2003).
13
Plahar et al (1997) conducted a study to develop an
appropriate household/small-scale enterprise level technique for
the production of soy-fortified fermented maize dough (or meal)
by comparing different treatments, processing methods and
fortification levels. Addition of whole soybeans to maize before
milling and fermentation reduced the fermentation time by 60%
while
increasing
the
protein
content
by
24%
and
70%,
respectively for 10% and 20% levels of fortification. Based on the
findings of the study, the most appropriate technique for the
production of soy-fortified high protein fermented maize dough
has been suggested to involve incorporation of boiled whole
soybeans in soaked maize before milling and fermentation for
improved sensory characteristics, enhanced nutritive value and
optimal functional properties.
Pregelatinized maize-sweet potato mix, fortified with
soybeans
and
groundnut
flours,
was
evaluated
for
its
acceptability as a weaning food and for nutrient composition. An
acceptable product had 14.3, 6.4, 2.4 and 67.4%, respectively,
for its protein, fat, ash and carbohydrate contents. Values for
calcium, phosphorus and and iron contents were 59.6, 187.5
and 2.4 mg/100 g, respectively, while the most predominant
14
fatty acids were linoleic, oleic and palmitic acids (Idowo et al
1993).
Nutritional composition and micronutrient status of
six
types
of
home
made
and
commercial
weaning
foods
consumed in Tanzania was examined by Mosha et al (2000).
Both home made and commercial weaning foods had some
shortcomings in terms of nutrient composition and energy
balance. Ca, Fe and Zn were the most common deficient
macro/micronutrients in the home made weaning foods. It was
suggested that, more efforts must be directed towards increasing
the concentration of Ca, Fe and Zn in the home made weaning
foods through supplementation of the starchy staples with
mineral rich foods.
Khalil and Chughtai (1984) studied the Nutritional
evaluation of wheat and maize breads supplemented with a
mixture of peanut-chickpea flour. Supplementation increased
the protein content of the wheat and maize blends by 20–61%.
Significant (p ≤ 0.05) increase in other proximate constituents as
well as K, Ca, P, Fe, Zn and Cu levels and lysine were observed.
A supplementation level of 20% was considered adequate to
achieve the desired nutritive benefits.
15
In the study by Theodore et al (2007) on nutritional
status of maize fermented meal by fortification with Bambara –
nut showed that Bambara-nut addition caused only minimal
changes in the proximate composition with the exception of
protein content, which increased remarkably from 10.1% to
16.4% and 10.1% to 16.2% with 20% bambara-nut addition
respectively for boiled and raw bambara-nut fortified fermented
maize dough. Based on the findings of the study, the application
of Bambara-nut fortification to traditional foods suggests a
viable option for promoting the nutritional quality of African
maize – based traditional foods with acceptable rheological and
cooking qualities.
Chemical composition and starch digestibility of
tortillas
prepared
with
non-conventional
commercial
nixtamalized maize flours were assessed. It was found that the
maize-bean mixed tortilla had the highest protein, ash and fat
contents and lower total starch than in the white and blue maize
tortillas. The maize-bean mixed tortillas exhibited the lowest in
vitro digestibility, which was consistent with the relatively high
resistant starch levels in the bean. The starch digestibility
features of these new types of nixtamalized maize flours open up
16
the possibility of producing tortillas with variable nutritional
properties (Salazar et al 2005).
Enwere and Ntuen (2006) studied the effect of
various concentrations of different ripe fruit pulp on the sensory
and nutritive quality of ready to eat breakfast cereal produced
from maize and soybean flours and cassava starch blends. The
samples containing 100 g pineapple, 100 g banana pulp and
100 g pawpaw fruit pulp per kilogram of composite flour
(equivalent to 7% of the total weight of the breakfast cereal
formulation) were the most acceptable of all concentrations.
Chemical analysis also showed that there was increase in βcarotene (vitamin A precursor) and vitamin C and a slight
increase in the mineral content of the breakfast cereal as a
result of the addition of fruit pulp.
Protein
and
starch
digestibilities
and
mineral
availability of five products developed from potato, soy and corn
flour were evaluated by Gahlawat and Sehgal (1998). It was
observed that protein digestibility increased by 12 to 17 percent
on baking or roasting of products. Processed products had
significantly higher starch digestibility and mineral availability
compared to raw products.
17
Tempe, an Indonesian mold fermented food, was
prepared from cowpeas and soybeans using the traditional
oriental process with modifications where appropriate. Four
complementary foods were developed from whole maize meal or
dehydrated fermented maize (ogi) flour fortified with either
cowpea tempe or soybean tempe. The nutrient content of all the
developed products were within the range prescribed by the
FAO/WHO pattern for processed weaning foods. Fortification
reduced the viscosity of the diets and the values reduced with
increasing
temperature.
Tempe-based
weaning
foods
reconstituted easily in hot water, while cooking destroyed most
of the microorganisms present. Maize-based tempe fortified
foods were relatively inexpensive and have potential as weaning
foods( Osundahunsi and Aworh 2002).
Improvement in the tortillas’s protein (9.2 to 12.%),
fat (1.8 to 4.9%), phosphorous (231-370 mg%) and linoleic acid
was achieved when whole flour air classification and starchy
fractions of raw amaranth seeds were employed in mixtures with
commercial lime treated corn flour or corn meal (Marroquin et al
1987).
18
Kumari and Singh (2004) studied the impact of
supplementation of QPM based ladoos on the nutritional status
of pregnant women and observed changes in haemoglobin level
of pregnant women after intervention with supplementary food.
It was found that around 13.3 percent of severe anaemic women
and 80 percent moderate anemic women shifted to mild anaemic
found after supplementation. Due to supplementation, the
newborn of the pregnant women in the experimental group had
normal body weight.
The growth and brain development of laboratory rats
on typical indigenous tortillas based diets were determined
throughout two generations. The comparision of three different
types of tortillas based diets: regular tortillas produced from dry
masa flour, tortilla produced from fresh masa flour and tortillas
obtained from dry masa flour fortified with 6 percent defatted
soybean and enriched with vitamin B 1, B2, niacin and folic acid
and microminerals like iron and zinc was observed between two
generations. Animals of each physiological stage were the first
for hematocrit determination and then slaughtered with the aim
of obtaining femur and brain tissues. Cerebral DNA and number
of neurons were determined in each of the brain sample. For
19
second-generation rats, these values were lower for animals fed
regular tortilla diets (Stylianopoulos et al 2002).
Akinyele and Fasaya (1988) observed that corn or
sorghum supplementation with cowpeas to prepare ogi, a
traditional weaning food in Nigeria increased protein from 7.1 to
14.9 percent, which would be good for feeding infants. The 60:
40 combinations could be used to maximize the effects of
supplementation.
Matz (1991) investigated the physical and chemical
losses of yellow corn. These were 65% in thiamin, 32% in
riboflavin,
31%
niacin,
33%
ether
extractables,
10%
in
nitrogenous substance and 21% in carotene originally present.
The hot lime water treatment increased the rate of release of
most of the essential amino acid so that masa was more
nutritious than corn flour.
High fiber tortillas could be produced by adding 100 g
oat bran of rice bran (Friend et al, 1993) and protein conte nt
could be increased by adding vital wheat gluten.
Feria Morales and Pangborn (1983) studied that since
corn was deficient in lysine and tryptophan, it could be enriched
20
with milk solids, soybean, oil seeds flours, sorghum, germinated
corn, potatoes and even cheese.
Amaya
et
al
(1997)
studied
the
physiological
development of laboratory rats fed with a typical indigenous
tortilla diet for two generations. Five different types of diet were
fed. The growth of rats fed tortillas produced from enriched dry
masa flour fortified with 6% defatted soybean meal (FEDMF) and
tortillas produced from enriched quality protein maize flour
fortified
with
3%
defatted
soybean
meal
(FEQPM)
was
significantly higher (p≤0.05) in both generation than their
counterparts fed tortillas prepared from enriched quality protein
maize flour (EQPM) obtained from fresh masa (FM) and regular
tortillas produced from dry masa flour enriched with vitamin Bcomplex and micro minerals(REDMF).
Bressani
et
al
(2004)
demonstrated
the
supplementary effects of protein quality of soybean product and
of the corn products used. Four types of corn flour of different
protein quality were used, which included to whole corn flours,
one from opaque-2 corn and one from degerminated corn.
Likewise, three soybean products were tested including solvent
extracted soybean flour, texturisied soybean products and a
21
soybean proteins isolate. Large increment in the quality were
observed with a addition of 5% soy protein, which became
smaller as this level increased, independent of the corn flour
used. The supplementary effects were more evident for low
quality corn flours and the best results were obtained with
addition of 5 percent soy protein.
Sanchez and Maya (1995) used whole flour and
milling fraction of raw amaranth seeds in 90:10,80:20and50: 50
mixtures with industrialized corn flour to prepare tortillas and
arepas. Amaranth whole flour and commercial corn flour
mixture in the proportion of 80:20 and 50:50 were found
suitable for the preparation of arepas. The protein rich (IR) and
starchy (2-R) fraction obtained by air classification, yielded good
results when substituting amaranth flour. Enrichment of this
product with whole amaranth flour is, therefore, recommended
for use in programs aimed at improving the nutritional status of
the population.
The nutritive quality of maize- soybean (70:30) tempe
flour manufactured by fermentation with rhizopus–oligosporus:
Rhizopus orysae (1:1) was determined using weanling rats. It
increased the content of reducing sugars, total acids and
22
aminonitrogen by about 43, 195 and 482%, respectively and
decreased phytate content by 46%. In vitro iron absorption for
maize flour and maize soybean tempe flour was 2.46 and 5.51
%. In vivo protein digestibility of the two products was 95.0 and
98.0%, respectively. (Tchango 2002).
Sawki et al (1999) analyzed effects on parameters of
glucose homeostasis in healthy humans from ingestion of
leguminous versus maize starches. Pure pea starch elicited less
hyperglycaemia (minus 47 %), hyperinsulinaemia (minus 54 %),
and C-peptide secretion (minus 37 %) as compared to corn
starch (p≤0.05). Pure pea and corn starches were equally well
tolerated, while flatulence and breath hydrogen concentration
were increased only after the intake of crude pea flour.
Sharma and Sankhala (2003) explored the use of
energy dense, shelf stable, acceptable and convenient corn
based mix as the supplementary food. Findings on quality
assessment revealed that plain as well as reconstituted dessert
furnished good amount of protein (5%, 2%), fat (28%, 6%),
carbohydrate (48%, 3%) and energy (473, 190kcal). On sensory
rating, this remained highly acceptable by the panelists during
the entire six months duration of storage. Free- fatty acid
23
content, a simple determinant of quality remained more or less
within the normal range.
A study conducted by Turnlund et al (1990) in
healthy young women to measure and compare the availability
of iron from cereal based diet with and without milk by use of in
vivo and in vitro methods. In vitro iron bioavailability tests
demonstrated that the amounts of soluble and ionizable iron in
cereal based diets increased two and three fold respectively
when milk was added. It was found that in vivo and in vitro
effects differ and that the absorption of iron from cereal based
diets is neither enhanced nor inhibited by the addition of milk.
3. Sensory evaluation of maize products
The various flour blends of maize and pigeon pea
were used for the preparation of doughnuts and biscuits.
Proximate composition and sensory attribute of the products
were analyzed using standards methods. The protein content of
the blends increased steadily with increasing content of the
pigeon flour while carbohydrate decreased. Similarly the protein
content of the biscuits and doughnuts increased with increasing
level of supplementation with pigeon pea. However the biscuits
made from either maize flour alone or wheat alone were
24
generally accepted than those made from the various blends
(Echendu 2004).
Estrada et al (1985) conducted a study to determine
sensory changes of fortified nixtamalized corn flour with lysine
and tryptophan up to 83,100 and 150% of suggested FAO
pattern after 2 months storage at room temperature (30 ˚C).
Tortillas made of enriched and normal corn flour were tested by
16 trained panelists. No significant differences were found in the
analysis of 19 descriptors of tortillas made of enriched and
normal nixtamalized corn flour after two months storage.
Effect of soybean substitution in the ratios of 100:0,
90:10, 80:20, 70:30, 60:40 and 50:50 on physical, compositional
and sensory properties of Kokoro (local maize snack) was
studied by Adelakun et al (2005). Protein and fat contents
increased, while carbohydrate content decreased as the soy flour
proportion of flour mixture was increased. The bulk density and
water-holding capacity increased with increasing proportion of
soybean flour,
while
the
swelling capacity was found to
decrease. Sensory evaluation indicated that Kokoro containing
maize: soybean flour mixture ratios of 100:0 and 90:0 were most
acceptable to the panelists.
25
Cornmeal
was
enriched
with
free
lysine
and
tryptophan and used for preparation of tortillas, which were
evaluated by a trained taste panel. The results indicated that
direct free amino acid supplementation of cornmeal for tortilla
manufacture could lead to the apperarance of off-flavours and
therefore adversely affect consumer acceptance (Mejia et al
1997).
Akpapunam and Darbe (1994) studied the chemical
composition
and
functional
properties
of
maize
blends
containing various levels of maize (100–0%) and bambara
groundnut
(0–100%).
Cookies
prepared
from
the
blends
contained proteins ranging from 10.9 to 21.7% .The cookies had
good spread and were significantly lighter than the wheat
control cookies. Sensory evaluation scores for cookies showed
that the best level of combination was 75% maize flour and 25%
bambara groundnut flour.
Chemical
and
selected
functional
properties
of
soybean flour (SF), maize flour (MF) and their blends were
determined in cookies. The protein contents of the composite
flour cookies increased from 10.2% in the 100% maize cookie to
28.3% for the 60% soybean substitution. Sensory evaluation
26
showed that the cookies (SF/MF) were not significantly different
(p ≥ 0.05) in colour, flavour and taste but differed significantly (p
≤ 0.05) in texture and overall acceptability. Cookies prepared
from the blends of 60% soybean flour and 40% maize flour were
the most acceptable one (Akubor and Onimawo 2003).
Plahar et al (2003) analysed the samples of extruded
high protein weaning foods that were produced using blends of
peanuts, maize and soybean to achieve the desired level of
protein. The extruded products were found to have better
nutritional quality as indicated by the high protein content of
16.5–18.7% and excellent rat growth response. In terms of
storage stability of the extruded products, predicted shelf life
periods of 7.8–10.4 months were obtained for the extruded raw
blend, and 5.6–7.1 months for the extruded preroasted blend,
when stored at the average ambient temperature of about 30,°C
in Ghana.
Galan et al (1991) studied the sensory and nutritional
properties of cookies based on wheat-rice-soybean flours in the
ratio of 50:45:5(I), 50:40:10(II) and 50:35:15(III), respectively,
that were baked in the microwave oven. Cookies of formula I and
formula II were preferred over formula III by consumer type
27
panel. Apparent protein digestibility and protein efficiency ratio
were significantly higher in formulas II and III than in formula I.
4. Effect of processing on nutritive value of maize flour
The effects of fortification method of the Ghanaian
tradition fermented maize dough with raw or heat-treated whole
soybeans
and
full
fat
soybean
flour
0%;
10%
and
20%replacement levels on the rate of fermentation and products
quality were investigated .the most appropriate technique for the
production of soy-fortified high protein fermented maize dough
has been suggested to involve incorporation of boiled whole
soybeans for 20 minutes in soaked maize before milling and
fermentation, for improved sensory characteristics, enhanced
nutritive value and optimal functional properties (Plahar et al
1981).
Cardenas et al (2001) evaluated the effect of the
addition
of
vitamins
and
soy
protiens
on
the
quality
characteristics of nixtamal tortillas (TN) and the losses of
nutrients
during
the
nixtamalization
process.
During
the
production of the tortillas corn lost approximately 1.5% of
proteins. In the process of producing nixtamal tortillas from
corn, 28.9% of the niacin, 46.3% of the folic acid, 36.35 of the
28
thiamine, 80% of the riboflavin were lost of the total. 63% loss
was during cooking and 16.6 % loss was during washing of
nixtamal.
The
chemical
changes
of
some
nutritional
components made from instant whole corn flour prepared by
extrusion process were evaluated and compared with tortillas
made by traditional process and raw corn. Tortillas from
traditional process showed lowest amount of total dietary fiber
and available lysine. The
thermal treatment in both the
processes decreased the ether extract and fatty acid content.
Tortillas
produced
by
extrusion
process
showed
better
nutritional characteristics than traditional tortillas prepared by
nixtamilization process. (Aldapa et al 2004).
Martinej
and
El-dahs
(1981)
observed
that
the
hydrothermal process using corn grits soaked in water at room
temperature (28-30 ˚C) for five hours and steaming for one
minute at 118˚C did not effect the proximal composition of the
corn flour. However, the amino acid content was reduced to
approximately 18 percent. Tortillas prepared with instant corn
flour showed better color and texture in comparison to the
tortillas prepared by the conventional process.
29
A study was planned to observe the effect of the
nixtamalization process on phytic acid, calcium, iron and zinc
contents in 11 varieties of whole maize and their germ and
endosperm. Phytic acid in the whole grain, endosperm and germ
decreased upon nixtamalization. Calcium was present in higher
amounts in the germ before and after nixtamalization. This
process increased the level of calcium for about 18 times in the
whole grain and the endosperm, and about 24 times in the germ.
As for iron, the germ contained higher amounts of zinc in both
raw and nixtamalized forms, than the endosperm. There was a
loss in zinc content in the endosperm processed by lime
cooking, but not in the germ (Bressani et al, 2002).
Ramalu and Rao (1997) analyzed effect of processing
on total dietary fiber (TDF), insoluble dietary fiber (IDF) and
soluble dietary fiber (SDF) content of rice, wheat, sorghum,
maize, ragi, bajra , whole grains of pigeonpea, chickpea, green
gram and lentil as well as their dehusked split dhals. Among the
cereals, rice had the lowest TDF (4.1%) and wheat had the
highest (12.5%) TDF content and of whole pulses, ranged from
15.8 percent in lentil to 28.3 percent in chickpea. Among the
dhals, green gram dhal had the lowest (8.2%, 6.5%) and
30
chickpea dhal (15.3%, 12.7%) had the highest TDF and IDF
contents, respectively. Processing of cereals had no effect on
their TDF and IDF contents, with the exception of ragi, where a
significant increase in TDF and IDF was observed.
Tejerina et al (1997) observed the effect of various
processing methods on the protein values of Maisoy, a blend of
30% whole soybean and 70% corn. Lime cooking as well as
extrusion cooking yielded a food with a protein efficiency ratio
ranging from 2.30 to 2.60. Both processes destroyed the
antiphysiological factors of soybean.
Khan
et
al
(1991)
studied
the
effect
of
heat
treatments on phytic acid content of maize products. Processing
of maize for the production of various traditional products
resulted in the loss of phytic acid. The loss of phytic acid varied
from 18.1 to 46.7% for fresh maize and from 11.5 to 52.6% for
dry
maize,
respectively,
among
all
the
treatments
given.
Consumption of maize as chapatti and after roasting in a sand
bath or on charcoal improved the availability of minerals.
Hazell and Johnson (1989) observed the influence of
food processing on iron availability (In vitro) from extruded maize
based snack foods. There was reduction in iron content due to
31
refining, but a small increase in iron content due to product
formulation and extrusion cooking was observed.
Maize and potato samples were extruded at high
temperature (120-140˚C) and pressure (500-900 p.s.i) and the
effect of iron absorption was measured by whole body counting
in rats using
59
Fe as an intrinsic label. These studies indicated
that extrusion cooking has no effect on the amount of iron
absorbed and that any iron picked up in the extrusion process
is as available for absorption as endogenous iron in the food
(Tait et al 1987).
Mestres et al (1990) studied the processing conditions
for making pasta of maize flour and durum wheat semolina in
the ratio of 66:33. It was found that extrusion conditions
affected the colour characteristics and cooking quality of the
pasta and heat treatment improved the cooking quality of pasta
by reducing cooking losses.
Mehta et al (1989) studied the effect of processing
technique on viscosity reduction properties, keeping quality and
suitability of weaning gruels for maize eating population. It was
found that viscosity was reduced in fully malted flour except the
malted one could be kept for 30 days. The gruel intake study
32
showed an increased intake for three experimental gruels as
compared to control being highest in amylase rich food added
gruel than made with fermented and par boiled maize flour.
The study was planned to develop the weaning gruel
from maize and maize - green gram dhal by using fermentation
technique and to explore the combined effect of fermentation
and malting on bulk reduction and other physico-chemical
properties. It was observed that the addition of legume leads to
an increase in bulk and improves the nutritional quality of
combined product. Addition of amylase rich food to such gruels
resulted in maximum reduction of viscosity (Mehta et al 1989).
33
CHAPTER III
MATERIALS AND METHODS
The present study was conducted for the sensory and
nutritional evaluation of products prepared from maize flour
supplemented with legumes, green leafy vegetables and milk and
milk
products.
Materials
and
methodology
adopted
conducting this piece of work have been described below:
3.1
Selection of products
3.2
Procurement of maize flour and other ingredients
3.3
Development of recipes
3.4
Organoleptic evaluation
3.5
Preparation of samples
3.6
Chemical analysis
3.6.1 Proximate composition
3.6.2 Lysine
3.6.3 Tryptophan
3.6.4 Total Iron
3.6.5 Ionizable iron
3.6.6 Calcium
3.7 Statistical analysis
3.8 Evaluation of protein quality of products
34
for
3.1
Selection of products
Eight products namely plain roti, gruel, methi roti,
palak poori, pancake, mixed vegetable pakoda, Namkeen para
and tacos were selected on the basis of their high frequency of
use in families. Since these are easy to prepare and ingredients
which are easily available at home have been used. The common
people can easily adopt these supplemented products based on
maize.
3.2
Procurement of ingredients
Maize flour was purchased from the local market.
Other ingredients required for supplementation of maize flour
like wheat flour, bengal gram flour, green leafy vegetables like
spinach and fenugreek and other vegetables, milk and its
products were also bought from the local market.
3.3
Development of products:
Eight products using maize flour as basic ingredient,
supplemented with legumes, vegetables and milk and milk
products were standardized. The products are shown in plates I
and II. Their recipes are given below:
35
I. Plain Roti
Ingredients
Maize Flour
Luke warm water
200 g
165 ml
Procedure:
1. Kneaded the dough with luke warm water.
2. Prepared equally sized five balls from the dough.
3. Shaped the rotis on rolling board with hand.
4. Prepared the rotis on hot griddle, turning upside down till
both the sides were done.
Note : Can be served with saag/vegetable curry/dhal.
No. of rotis = 5
Cooked weight = 275g
II. Gruel
Ingredients
Crushed Maize roti
35 g
Milk
75 ml
Sugar
7g
Procedure:
1. Crushed the maize chapatti (preferably after cooling) into
small granules.
36
2. Added hot milk and sugar to crushed chapatti.
3. Mixed and served hot.
Note: Left over roti can also be used after warming it a little.
Cooked weight: 120 g
III. Methi Roti
Ingredients
Maize flour
150 g
Bengal gram flour
50 g
Fenugreek leaves
100 g
Green chilies
2
Salt
½ tsp
Water
175 ml
Procedure:
1. Mixed maize flour and bengal gram flour together.
2. Chopped
the
fenugreek
leaves
and
green
chillies
after
washing these thoroughly and made into a paste in a mixer
grinder.
3. Mixed this paste and salt with above flour mixture.
4. Prepared dough with luke warm water.
5. Divided the dough into five equally sized balls.
6. Prepared roti on the rolling board with hand only.
37
7. Served hot with curd.
No. of rotis: 5
Cooked weight: 300 g
IV. Palak Poori
Ingredients
Wheat flour
150 g
Maize flour
150 g
Spinach
150 g
Water used
50 ml
Oil
30 ml (for the dough)
Salt
a pinch
Oil
for frying
Procedure:
1. Mixed the two flours together and rubbed the oil in it.
2. Spinach leaves were cleaned, washed thoroughly and then
blanched.
3. After draining spinach leaves were ground to paste.
4. Mixed spinach paste and salt with the flour mixture and
made a hard dough with luke warm water.
5. Made 17 equally sized balls from the dough.
6. Rolled them into the shape of pooris with rolling pin and
board.
38
7. Fried till golden brown in hot oil.
8. Served hot with channas.
Cooked weight
No. of pooris
: 425 g
:17
V. Namkeen Para
Ingredients
Maize flour
100 g
Bengal gram flour
50 g
Refined wheat flour
50 g
Salt
1 tsp
Ajwain
½ tsp
Oil
25 g (for the dough)
Water
100 ml
Oil
for frying
Procedure:
1. Mixed all the three flours and salt and ajwain.
2. Rubbed the mixture with oil and kneaded to form a hard
dough with water and kept it aside.
3. Rolled the dough to ½ cm thickness.
4. Cut the rolled dough with knife in the shape of diamonds.
5. Fried them till golden brown.
39
* Can be stored for later on use.
Cooked weight: 110g
VI. Mixed Vegetable Pakodas
Ingredients
Bengal gram flour
100g
Maize flour
100g
Potatoes
120g
Onion
120g
Cauliflower
120g
Green chilies
2-3
Salt
1 tsp
Chat masala
½ tsp
Oil
for frying
Method
1. Peeled potatoes and onions washed and sliced them.
2. Cut cauliflower into florets and washed thoroughly.
3. Chopped the green chilies finely and mixed with the
vegetables.
4. Made a thick batter of maize flour and bengal gram flour
and added salt and Chat masala.
5. Dipped the prepared vegetables in the batter and deep fried
in hot oil to light brown color.
40
6. Took them out and pressed.
7. Then fried them again till golden brown.
8. Served hot with tomato sauce and mint chutney.
Cooked weight: 615g
VII. Pancakes
Ingredients
Maize flour
100g
Bengal gram flour
100 g
Curd
100g
Carrots
50g
Onion
25 g
Capsicum
30 g
Salt
1 tsp
Red chilly powder
½ tsp
Chat masala
½ tsp
Water
290 ml
Oil
for frying
Procedure:
1. Mixed both the flours with curd.
2. Grated all the vegetables and added to the above mixture
41
3. Prepared a batter of the consistency which could easily
spread on pan and added spices in it.
4. Kept the above-prepared batter for 10 minutes.
5. Greased the hot non-stick pan and spreaded the batter giving
the shape of pancake.
6. Cooked from both sides till light brown.
7. Serve it with tomato sauce/ mint chutney.
Cooked weight: 450 g
No. of pancakes prepared:17
VIII. Tacos
Ingredients
Maize flour
150g
Wheat flour
75g
Carrots
75 g
Onion
50 g
Peas
100g
Paneer
150g
Tomato
50 g
Salt
10g
Red chilly powder
5g
Water
110 ml
42
Oil
15g (for the dough)
Oil
for frying
Procedure
1. Mixed the maize flour and wheat flour together.
2. Rubbed 15 g of oil in it and then kneaded to form a smooth
dough with water and kept aside.
3. Blanched peas and mashed them.
4. Chopped the onions.
5. Grated the carrots, cheese and tomato.
6. Cooked this vegetable mixture along with seasoning till done.
7. Made small balls of dough, flattened it to make its shape.
8. Folded it and placed a steel spoon in it and then fried it.
9. After frying filled the prepared mixture in it.
10. Served hot with tomato sauce.
Cooked weight: 340 g
No. of tacos: 17
3.4 Organoleptic evaluation
To study the acceptability of the products prepared
from maize flour supplemented with legumes, vegetables and
milk and milk products, organoleptic evaluation of these
products was carried out. A panel of 10 judges consisting of
43
faculty and senior students of department of Food and Nutrition
evaluated the products. The products were judged on the
various parameters like color, appearance, flavor, texture, taste
and overall acceptability by using nine-point hedonic scale
(Srilakshmi 2005). The scores assigned were as follows:
Grading
Like extremely
Scores
9
Like very much
8
Like moderately
7
Like slightly
6
Neither like nor dislike
5
Dislike slightly
4
Dislike moderately
3
Dislike very much
2
Dislike extremely
1
The organoleptic score card used for sensory evaluation has
been given in Annexure 1.
3.5 Preparation of samples for analysis
The prepared products were first dried in oven at
60°C for five hours. These were allowed to cool down in
dessicator. The dried samples were ground to fine powder in
44
mortar and pestle and then stored in airtight containers. Then
these
products
were
subjected
to
chemical
analysis
for
proximate composition, amino acids i.e. lysine and tryptophan,
minerals i.e total and ionizable iron and calcium.
Chemical Analysis
3.6.1 Proximate composition:
Moisture (AOAC 1980)
Procedure
Weighed sample of finely ground material (10g) was
dried in a hot air oven for 8 hours at 105°C. China crucible with
dried material was transferred immediately to desiccator, cooled
and weighed.
Calculations
Moisture % =
loss in wt (g)
Wt of sample (g)
X 100
Crude Protein (AOAC 1980)
Crude protein was determined by macro-kjeldahl
method as total N and a factor of 6.25 for conversion of N into
protein was used.
Reagents:
1. Conc. H2SO4
45
2. Digestion Mixture: 1 part CuSO 4 and 9 parts of K 2SO4
3. Boric acid, 4%
4. NaOH, 40%
5. Mixed indicator: 0.1 g methyl red and 0.5g bromocresol green
were dissolved in 100 ml of 95% ethanol
6. 0.1N H2SO4
Procedure:
Digested weighed sample (500 mg) with conc. H 2SO4
(25 ml) after adding 3-5 g of digestion mixture in a Kjeldahl flask
till it turned clear bluish green and all nitrogen present was
converted to (NH 4)2SO4. Cooled solution was used for distillation
either as single sample or multiple samples after making volume
to 100 ml.
Digested solution in a flask was taken for distillation
after adding 50 ml of 40% NaOH and 100 ml of water. After
addition to NaOH immediately fixed the flask to a condensor
having a 250 ml flask containing 25 ml of 4% boric acid with
mixed indicator. Carried out the distillation and when distillate
becomes almost double stop the distillation and titrated the
distillate with 0.1N H 2SO4 to a pink red end point. A blank was
also run with the sample.
46
Calculations
N%=
Vol. Of 0.1 N (g) H2SO4 used x 0.0014
Wt of sample (g)
X 100
% Crude protein = % N x 6.25
Total ash (AOAC 1980)
Weighed 5 g of sample in crucible of known weight.
Ignited and placed in a muffle furnace at 550 °C for 4 hrs.
Weighed the residue left in the crucible and the weight of the
crucible was substracted.
Calculations
Ash % =
Wt of ash (g)
Wt of sample (g)
X 100
Crude fat (AOAC 1980)
Procedure
Prepared thimble from whatman no.1 sheet with the
help of thread and 2 cm diameter test tube. Weighed 5g of
moisture free sample and transferred it to the thimble. Plugged
the mouth of the thimble with fat free absorbent cotton and
placed it in the soxhlet assembly. Petroleum ether (40- 60 ml)
was poured in the flask to 1.5 times capacity of soxhlet
47
assembly and fitted the apparatus with condenser to a water tap
for cold circulation. Started the apparatus by fixing at 60°C and
run for 18 hrs taking care of the tap water and ether in the
flask.
At
the
end evaporated ether
in
the
flask
and
transferred the contents to a pre-weighed crucible using small
quantities of petroleum ether. Evaporated ether in the crucible
on water bath and weighed.
Calculations
Crude fat % =
Wt of fat (g)
Wt of sample (g)
X 100
Crude fibre (AOAC 1980)
Reagents:
1.25% H2SO4
1.25% NaOH
Procedure:
Weighed 5g of moisture and fat free sample in a 500
ml beaker and added 1.25% H 2SO4. Boiled for 30 min and
filtered
through
muslin
cloth
using
buchner
funnel
and
filteration flask. Washed the residue with water till it was acid
free and transferred the residue to the beaker. Added 200 ml of
48
1.25% NaOH to the beaker and boiled for 30 min. again filtered
through muslin cloth and washed with hot water. Transferred
the residue to a pre-weighed crucible and dried to a constant
weight at 100°C in a hot air oven. Residue was then ashed in a
muffle furnace. Loss in weight was recorded.
Calculations
Crude fiber % =
Wt of residue – wt of ash after ignition
X 100
Wt of sample
3.6.2 Available lysine {Carpenter (1960) modified by Booth
(1971)}
Principle:
The procedure involves conversion of lysine residues
with reactive epsilon amino groups in the food proteins into a
yellow
epsilon
dinitrophenyl
lysine
by
treatment
with
fluorodinitrobenzene followed by acid hydrolysis. Ether soluble
interfering compounds are removed by extraction and extinction
of the residual aqueous layer is measured. A blank value is
obtained by treatment with methyl carbonyl chloride and
extraction of ether soluble compound.
49
Reagents:
1. 8% NaHCO3
2. Ethyl alcohol
3. 1 Flouro-2-4-dinitrobenzene (FDNB)
4. 1 N HCl, 8.1 N HCl, conc. HCl AR
5. Ethyl ether
6. Buffer pH 8.5 (19 parts 8% NaHCO 3 and one part 8.1%
Na2CO3)
7. 2N Na OH
8. Methoxy carbonyl chloride
Procedure:
STAGE I:
In 8 ml of 8 percent NaHCO 3 added 0.5 g of the
defatted sample in conical flask and 12 ml of ethyl alcohol
containing 0.3 ml of FDNB. Shaked for one hour in a water bath
cum shaker at 50 °C. Evaporated ethanol on hot water bath and
then added 24 ml of 8.1 N HCl to the flask. Refluxed contents
gently for 16 hours. Made the volume to 100 ml and then filter.
STAGE II: Taken two ml of filtrate in three tubes A, B and C
marked at 10 ml. Extracted the contents of tube A with
approximately 5 ml of ethyl ether twice and discarded ether
50
layer. Kept the tubes immersed in hot water to remove residual
ether and made the volume to 10 ml with 1 N HCl.
STAGE III: To tube C added one drop of phenolphthalein as an
indicator and titrated against 2N NaOH. Added same amount of
alkali to tube B. after that added 2 ml of buffer(ph 8.5).
Dissolved any precipitates formed by adding 0.05 ml methoxy
carbonyl chloride with vigorous shaking for ten minutes and
added 0.75 ml of conc. HCl dropwise. Extracted the contents
with ethyl ether twice and discarded the ether layers. Removed
excess ether by placing the tubes in hot water and made volume
to 10 ml with 1 N HCl after cooling the tubes.
STAGE IV: Measured the optical density (O.D) of the contents of
tubes A and B at 430 nm(mµ), difference in O.D. of tubes A and
B was taken as optical density due to DNP lysine and was
compared with corresponding values obtained with 2 ml of
standard E_DNP lysine solution.
Standard Solution
Dissolved standard E-DNP lysine HCl 12.5 mg in 250 ml in 1 N
HCl
51
Standard curve
From the standard solution 0.4, 0.8,1.2, 1.6 and 2.0
ml having concentration of E-DNP lysine HCl from 20 µg to 100
µg per ml were taken and made to 10 ml with distilled water.
The optical density was measured at 430 nm in spectronic-20
A blank was also run with standard and unknown samples.
Calculations
Available lysine: g available lysine/100g protein=
=
0.851 x 0.4862 x dil. Factor x 100 x 100 x conc. Of E -DNP lysine HCl.H2O
Weight of sample x percent protein
3.6.3 Tryptophan Estimation ( Concon 1975)
Reagents:
1. Acetic acid – FeCl3 solution: Dissolved 0.54 g FeCl 3 in 1 ml
water containing few drop of acetic acid to prevent
formation of insoluble ferrous hydroxide. To 0.5 ml of this
solution added glacial acid containing 2% acetic anhydride
and made the volume to one litre
2. 25.8 N H 2SO4
3. 0.075N NaOH
52
0.16
0.14
O.D. (430 nm)
0.12
0.1
0.08
0.06
0.04
0.02
0
20
40
60
Concentration (m g)
Fig. 1 Standard curve of lysine
53
80
Procedure:
Weighed 100 mg of defatted sample in a test tube and
added 10 ml of 0.075N NaOH. Shaked the test tubes in a
mechanical shaker for 1 hour. Centrifuged the contents at
12000 rpm for 15 minutes and decanted the supernatant.
Determined the protein in the supernatant using micro-kjeldahl
method. For estimation of tryptophan took 1 ml of protein
extract in a test tube and added 3 ml of glacial acetic acid-FeCl3
solution. Then added 2 ml of 25.8 N H 2SO4 rapidly and mixed
well. Stabilized the colour by incubating the sample at 60°C for
45 minutes. Cooled to room temperature in ice water bath and
read absorbance at 545nm against reagent blank. Prepared
standard curve using 40-200 µg of tryptophan and determined
the concentration in unknown from the standard curve.
Total Iron (AOAC 1980)
Principle:
Iron is released by mild acid treatment and the
released iron (Fe+++) is reduced to Fe++ by reducing agents and
then this Fe++ is reacted with ortho-phenanthroline to form a
pink colour complex, whose intensity can be measured at
540nm.
54
0.07
0.06
OD(545 nm)
0.05
0.04
0.03
0.02
0.01
0
0
0.5
1
Concentration(µg)
Fig. 2 Standard Curve for tryptophan
55
1.5
Reagents:
1. Conc. HCl
2. Ortho-phenanthroline solution: Dissolved 0.1 g of ophenanthroline in 80 ml glass distilled water at 80°C,
cooled and made the volume to 100 ml
3. 10% hydroxylamine hydrochloride
4. Acetate buffer solution: Dissolved 8.3 g anhydrous sodium
acetate in glass distilled water. Added 12 ml acetic acid
and diluted to 100 ml
5. Standard iron solution: Dissolved 3.512 g of ferrous
ammonium sulphate in water. Added 2 drops of HCl and
diluted to 500 ml. Diluted 10 ml of this solution to 1 litre
(1ml= 0.01 mg iron)
Procedure:
The extract prepared after ashing the food sample
was used for the estimation of iron. 10 ml of aliquot are pipetted
in the 25 ml volumetric flask and added 1 ml of hydroxylamine
hydrochloride solution. In a few minutes, added 5 ml of buffer
solution and 1ml of the o-phenanthroline solution. The contents
were mixed and volume was made upto the mark. The intensity
56
of
colour
developed
was
measured
at
540
nm
in
a
spectrophotometer.
Blank: 2 ml of conc. HCl was diluted to 100 ml and 10 ml of this
solution was treated as per sample.
Standard: 5,10,20,30,40 and 50 ml of standard iron solution
were transferred to 100 ml volumetric flask. Added 2 ml of conc.
HCl to each flask and volume was made to 100 ml. Aliquot of 10
ml of each flask were heated as in the case of sample. A
calibration curve was drawn with reading of standard solution.
The concentration of iron in the unknown sample was calculated
from the standard curve and multiplying with the dilution
factor.
3.6.5 Ionizable Iron (Rao and Prabhavati 1978)
Free form of the iron in the filtrate reacts with alphaalpha- dipyridyl to yield colour, obtained after incubation of the
samples with pepsin-HCl at 1.35 and 7.5 as described by AOAC
(1985). This form of iron corresponds to the ionizable iron. The
percentage of iron absorption was determined by the regression
equation of Rao and Prabhavati (1978) as given below:
Y = 0.4827 + 0.4707X
57
0.8
0.7
OD (540 nm)
0.6
0.5
0.4
0.3
0.2
0.1
0
0
2
4
6
8
Concentration
Fig. 3 Standard Curve for total iron
58
10
Where,
Y = % Fe absorption in adult
X = ionizable Fe at pH 7.5
Reagents
Alpha-Alpha dipyridyl solution: Dissolved 0.1 g of alphaalpha-dipyridyl in distilled water and incubate to 100 ml in
volumetric flask.
Acetate buffer solution: Dissolved 8.3g of anhydrous sodium
acetate (AR) in distilled water followed by the addition of 12 ml
of glacial acetic acid (AR) and volume made to 100 ml. The
contents were filtered through Whatman no.1 filter paper.
Hydroxylamine
hydrochloride
solution:
Dissolved
10g
of
Hydroxylamine hydrochloride in distilled water and diluted to
100 ml.
Procedure:
From the aliquot, pipetted 1.0 ml into 10 ml volumetric flask and
added 1ml of hydroxylamine hydrochloride solution. After few minutes,
added 5 ml of buffer solution and 1 ml of alpha-alpha-dipyridyl solution and
the volume was made upto 10ml. Read the intensity of colour against reagent
blank, in spectrophotometer at 510 nm.
59
Standard curve
Dissolved 702.2mg of ferrous ammonium sulphate
[Fe (NH4) 2.6H2O AR] in 100 ml distilled water to which 5ml of
dilute HCl (1:1) was added and volume was made to one liter.
Diluted 10 ml of this solution to one liter (100 µg Fe/ ml) and
used as a working solution. Added 0.4 ml, 0.6ml, 0.8 ml, 1ml of
working standard solution and proceeded, as in case of the
sample solution and standard curve was plotted.
3.6.6 Calcium (Hawk et al 1957)
Calcium is precipitated as oxalate and is titrated with
standard potassium permanganate.
Reagents:
1. 4% ammonium oxalate solution
2. Dilute ammonia solution (2ml of liquor ammonia +98 ml
water)
3. 1N H2SO4
4. 0.01N potassium permanganate solution
5. 0.01N oxalic acid
Procedure:
2 ml of sample was taken into a 15 ml centrifuge
tube. Added 2ml of distilled water and 1 ml of 4% ammonium
60
0.1
0.09
O.D. (510 nm)
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
2
4
6
8
Concentration (µg)
Fig.4 Standard curve for ionizable iron
61
10
oxalate solution and mixed thoroughly and left overnight. Again
the contents were mixed and centrifuged for 5 min at 1500 rpm.
The supernatant liquid was poured off and the centrifuge tube
drained by inverting the tube for 5 min on a rack. The mouth of
the centrifuge tube was wiped with a piece of filter paper. The
precipitate was stirred and the sides of tubes were washed with
3 ml of dilute ammonia. It was centrifuged again and drained as
before. The precipitates was washed once more with dilute
ammonia to ensure the complete removal of ammonium oxalate.
The precipitate was dissolved in 2 ml of 1N H 2SO4.
The tube was heated by placing it in a boiling water
bath for 1 min and titrated against 0.01 KmnO4 solution to a
definite pink colour persisting for atleast 1 minute.
Calculation:
1 ml of 0.01 KmnO4 is equivalent to 0.2004 mg of calcium.
3.7 Statistical analysis
The mean and standard deviation of the values for
sensory evaluation, proximate composition, minerals i.e. total
iron and ionizable iron as well as amino acids i.e. lysine and
tryptophan content of the developed eight recipes prepared from
62
maize flour were worked out for meaningful presentation of the
result.
3.8 Evaluation of protein quality of products
NDpCal%
expresses
the
percentage
of
calories
derived from protein corrected for efficiency of protein utilization
(FAO, 1965). It is one of the methods for the prediction of
protein value of foods and meals. Only in 1961, Miller and Payne
proposed
the
equation
for
NDpCal%
and
developed
the
nomograph indicating the relationship between ‘ protein score’
and protein of the diet as percent of calories. This method is
advantageous over other biological and chemical methods,
because (i) NDpCal% can be calculated easily from Food Value
Tables, it is easy to apply in field work and for large samples,
and (ii) it gives protein value in relation to calories. A diet
containing adequate NDpCal% will provide enough protein if
calorie intake is sufficient.
In the present study, the protein value of recipes has
been calculated by using the equation proposed by Miller and
Payne(1961) i.e.
NDpCal%= Protein calorie% X ‘chemical score’
63
(i)
Determination
of
Protein-Calorie
Percent
(PCal%)-
percentage of energy supplied by protein was calculated
from the equation:
Protein content x 4
P Cal% =
X 100 (Miller and Payne 1959)
Metabolisable energy
For this purpose protein and calorie content of the
ingredients were taken from the Indian Food Composition Table
(ii) Determination of Chemical Score – Chemical score was
calculated from the formula:
=
L.A.A in test sample
X 100
Amount of the same in Reference Protein
The amino acid composition of proteins was taken
mainly from the nutritive value of Indian Foods. As the lysine
was found to be most limiting amino acid in maize therefore
‘Protein Score’ has been calculated on this basis.
NDpCal% was read of the nomograph designed by
Miler and Payne (1961) after calculating the ‘Protein Calorie
percentage’ and
‘ Chemical score’. An example of determining
NDpCal% in methi roti with curd is given in table 3.1
64
Table 3.1
Example of scoring a recipe
Recipe - Methi roti with curd
Food
Wt(g)
(a)
Protein(g
/100g)
(b)
Cal/
100 g
AA/g N
Ng
Cal
AA g
(d)
(e)
(f)
(g)
(c)
(a xb/ (a x c/100) (d x e)
6.25 x 100)
Maize
flour
150
11.1
342
0.2
1.77
342
0.35
Bengal
gram flour
50
20.8
372
0.44
1.66
186
0.73
Fenugreek
leaves
100
4.4
49
0.3
0.7
49
0.02
Curd
375
3.1
60
0.48
1.86
225
0.89
Total
6.88
973
Quantity factor
Protein Cal%= e/f X 6.25 X 100 = 6.88/973 X 6.25 X 4 X 100
=17.67 %
Quality factor
g
Score =
X 100
e x Egg factor of lysine
2.17
=
X 100
6.88 x 0.44
= 71.61 %
65
2.17
NDpCal% = between 9.5
(read from nomograph)
Note:
1. b and c are values taken from food composition tables
given by Gopalan et al,2004.
2. d is the amount of limiting amino acid present per g of N in
each ingredient.
3. e,f,g are the total amounts present in each ingredient.
66
CHAPTER – IV
RESULTS AND DISCUSSION
The
maize
flour
based
nutritious
recipes
were
prepared by using legumes, milk and milk products, green leafy
and other vegetables which were organoleptically evaluated and
chemically analyzed by using various methods. The results are
discussed under the following headings:
4.1 Development of recipes
4.2 Organoleptic evaluation of maize flour based recipes
4.3 Chemical analysis
4.3.1Proximate Composition
4.3.2 Available Lysine
4.3.3 Tryptophan
4.3.4 Calcium
4.3.5 Total Iron
4.3.6 Ionizable iron
4.4 Cost of maize based nutritious products
4.5 Calculations of nutritive value on fresh weight basis
4.6 Evaluation of protein quality of products
67
4.1 Development of recipes
Plain roti was prepared in the traditional way and was
used as standard. All other seven products were supplemented.
Four were supplemented with bengal gram flour like methi roti,
pancake, mixed vegetable pakoda and namkeen para. Green
leafy vegetable like fenugreek leaves, spinach were added to
methi roti and palak poori respectively whereas other vegetables
were added in mixed vegetable pakoda, pancake and tacos. Milk
and milk products were added in gruel, pancake and tacos.
Since maize flour is deficient in essential amino acids like lysine
and tryptophan, the bengal gram flour being rich in lysine was
incorporated in the products. Similarly milk and milk products,
being rich source of calcium, lysine as well as tryptophan were
used. Green leafy vegetables contributed to higher amount of
lysine and tryptophan as well as iron and calcium.
 Gruel had double the amount of milk in crushed roti with
added sugar. Milk improved the quality of protein as well as
calcium of the gruel.
 In methi roti 25 percent of the maize flour was replaced by
bengal gram flour and fenugreek leaves were added in ratio of
1:2 (w/w) i.e. 100 g leaves in 200 g of mixed flour.
68
 In palak poori, maize flour, wheat flour and spinach were
mixed in equal proportions so that poori could be shaped
well. Spinach added colour and taste to the poori, it made it
softer besides making it nutritious.
 Generally pancakes (poora) are made with bengal gram flour
but here half of the bengal gram flour was replaced with
maize flour and the batter was fermented by using curd in the
ratio of 1:1:1(w/w). Vegetables were added to make it tasty.
Pancakes can be served as complete meal as it contains
cereal, pulse, milk product, vegetables and fat.
 Similarly in mixed vegetable pakodas also half the bengal
gram flour was replaced with maize flour which resulted in
more crisp end product.
 Namkeen para were prepared by using maize flour, refined
wheat flour and bengal gram flour in the ratio of 2:1:1 (w/w).
 The last product tacos where the maize flour and whole wheat
flour were mixed in the ratio of 2:1 (w/w) and cottage cheese
was added along with vegetable to improve the protein
quantity as well as quality.
69
Table 4.1 Basic composition of maize flour based products
S. no.
Name of the
product
Grain flours (g)
Vegetables (g)
M.F
B.F
W.F.
R.W.F.
GLV
OV
Milk and its
products (g)
1
Gruel
40
-
-
-
-
-
80 ml milk
2
Methi roti*
150
50
-
-
100
-
-
3
Palak poori*
150
-
150
-
150
-
-
4
Pancake*
100
100
-
-
-
105
100 g curd
5
Mix veg. Pakoda*
100
100
-
-
-
360
-
6
Namkeen para*
100
50
-
50
-
-
-
7
Tacos*
150
-
75
-
-
275
* Oil was used for frying
M.F.
Maize flour
B.F.
Bengal gram flour
W.F
Wheat flour
R.W.F.
Refined wheat flour
GLV
Green leafy vegetables
O.V
Other vegetables
70
150 g paneer
4.2 Organoleptic evaluation of maize flour based recipes
Seven products were prepared by supplementing the
maize flour with ingredients that were inexpensive and easily
available
in
the
local
market.
These
products
were
organoleptically evaluated by a panel of judges from the
department of Food and Nutrition by using nine-point hedonic
scale (Srilakshmi 2005) to judge the acceptability of the product.
Plain roti was prepared by traditional method and
used as standard for comparison. Parameters like appearance
and
taste
got
higher
scores
of
8.0
followed
by
overall
acceptability, colour, texture and aroma i.e 7.9,7.8,7.7 and 7.6
respectively.
Gruel was prepared by adding milk and sugar to the
crushed maize roti. Taste and overall acceptability got highest
score i.e 7.6 followed by texture, colour, appearance and aroma
in descending order 7.5,7.4 and 7.2, respectively.
Methi roti was prepared by supplementing maize flour
with Bengal gram flour with addition of fresh fenugreek leaves,
green chillies and salt. It got average score of 7.5 for aroma
whereas colour and taste earned 7.4 each. Overall acceptability
and appearance earned 7.3 scores each and minimum score
71
(7.0) was given to texture. Echendu (2004) also observed that
biscuits made from either maize flour alone were generally more
accepted than those made from the various blends of maize and
pigeon pea.
Palak poori was prepared by using a mixture of maize
flour, wheat flour and spinach was added after blanching and
grinding. As per the taste the highest score was 7.9 among all
the other parameters followed by overall acceptability with a
score of 7.85 while least score was earned by aroma (7.3) and
scores for other parameters ranged in between 7.7 to 7.8
indicating that poori was liked very much.
Pancake was a fermented product of maize flour
supplemented with bengal gram flour. Curd was used for
fermentation and cooked vegetables were added. It was ranked
highest for all the parameters like for taste, overall acceptability,
texture, colour, appearance and aroma with the average score of
8.7, 8.6, 8.5, 8.4,8.3 and 8.1, respectively on the basis of nine point hedonic scale.
Mixed Vegetable Pakoda were prepared by replacing
fifty percent of bengal gram flour with the maize flour. Taste of
this product was highly acceptable with a mean score of 8.5 and
72
parameters like appearance, texture and overall acceptability
were at 8.1 each followed by colour and aroma with a mean
score of 7.9 and 7.8, respectively.
Namkeen para was prepared by supplementing maize
flour with bengal gram flour and refined wheat flour. It was
highly acceptable with the mean score of 8.2 for appearance and
overall acceptability while colour and taste had mean score of
8.1 each and texture got mean score of 8.0. Only aroma got least
score of 7.9.
Tacos were developed by supplementing maize flour
with wheat flour. Cottage cheese was added to increase the taste
as well as protein quality of the tacos whereas other vegetables
like peas, onion, tomato and carrots were also added to increase
the palatability of the product. Overall acceptability score was
maximum at 8.1 while the other parameters viz appearance,
aroma and taste got scores of 7.9 each and colour and texture
were at 7.8 and 7.7 respectively.
While concluding the sensory evaluation of all the
recipes, it was observed that none of their parameters earned
average score below 7.0 points that means these products were
liked very much.
73
Table 4.2 Sensory Evaluation of Maize flour based products on Dry Weight Basis (Per 100 g)
S. No.
Product
Colour
Appearance
Aroma
1
Plain roti
7.8±0.40
8.0±0.45
7.6±0.49
7.7±0.46
8.0±0.45
7.9±0.3
2
Gruel
7.4±0.49
7.2±0.60
7.2±0.60
7.5±0.67
7.6±0.66
7.6±0.49
3
Methi roti
7.4±0.66
7.3±0.64
7.5±0.81
7.0±0.77
7.4±0.66
7.3±0.64
4
Palak poori
7.7±0.46
7.8±0.60
7.3±0.46
7.8±0.40
7.9±0.54
7.85±0.32
5
Pancake
8.4±0.49
8.3±0.46
8.1±0.30
8.5±0.50
8.7±0.46
8.6±0.49
6
Mix Veg
Pakoda
7.9±0.30
8.1±0.54
7.8±0.60
8.1±0.54
8.5±0.50
8.1±0.54
7
Namkeen
Para
8.1±0.30
8.2±0.40
7.9±0.54
8±0.45
8.1±0.54
8.2±0.40
8
Tacos
7.8±0.40
7.9±0.54
7.9±0.30
7.7±0.46
7.9±0.70
8.1±0.54
Values are mean ± S.D.
74
Texture Taste
Overall
acceptability
4.3 Chemical analysis
4.3.1 Proximate composition
The developed maize flour recipes were analysed and
the proximate composition on dry weight basis is given in table
4.3.1.
Moisture
The proximate composition of the eight developed
maize flour preparations on dry weight basis is shown in the
table 4.3.1. The moisture content of these products ranged
between 4.19 ± 0.10 to 5.41 ± 0.02 percent, the lowest being in
namkeen para and the highest in tacos. Tacos were prepared by
supplementing the maize flour with wheat flour and had filling
of vegetable and cottage cheese. The palak poori with 4.65 ± 0.06
percent moisture was prepared with the combination of maize
flour, wheat flour and spinach. Among the products prepared
from maize flour supplemented with bengal gram flour, the
moisture content was found to be highest in the pancake (5.32 ±
0.001 %) which were prepared with maize flour, bengal gram
flour, curd and vegetables and lowest in namkeen para with
4.19 ± 0.10 percent. Methi roti had moisture content of 4.50 ±
0.10 percent whereas mixed vegetable pakodas had 4.70 ± 0.08
75
percent moisture. The moisture content of product prepared
with the addition of milk i.e. gruel was 4.46 ± 0.06 percent.
However the variation in the moisture content was not too
much.
Crude protein
The legumes have higher content of protein and are
rich in lysine. Therefore in the present investigation a few of the
maize based recipes were supplemented with bengal gram flour.
Improvement in protein quality in akara prepared from cowpeas
and white maize (30:70 w/w) flour blend has been reported by
Giami et al (2003) while Khalil and Chughtai (1984) reported the
supplementation level of 20 percent of peanut-chickpea flour in
wheat and maize breads to be adequate to achieve the desired
nutritive benefits.
The crude protein content of all the developed recipes
in the present study ranged from 6.07 ± 0.01 to 9.31 ± 0.01
percent on dry weight basis with the maximum value of 9.31 ±
0.01 percent in Tacos and minimum being in methi roti. A little
low value for crude protein was observed in plain maize roti 9.04
± 0.21 percent and Namkeen para 8.43 ± 0.01 percent. Pancake
had protein content of 8.78 ± 0.01 percent. Reddy et al (1991)
76
reported the crude protein content of maize chapatti as 8.76
percent which was very close to the value obtained in plain roti
in the present study.
The maize flour products supplemented with wheat
flour were palak poori and tacos. Tacos got highest protein
content of 9.31±0.01 percent as it had filling of mixture of
vegetables and paneer whereas palak poori with protein content
of 6.82 ± 0.10 percent had only spinach puree added into it.
Addition of green leafy vegetables also improved the protein
quality of the products to certain extent, as these are rich in
lysine.
Crude fat
There was a wide variation in crude fat content in
selected maize based products. It ranged from 2.11 ± 0.01
percent in plain roti to 37.69 ± 0.18 percent in Namkeen para.
The variation in fat content was observed due to the amount of
fat used in the recipe as well as the cooking method employed.
Crude fat content of plain roti and methi roti was 2.11
± 0.01 and 2.49 ± 0.03 percent respectively as no fat was
smeared on these. But addition of little butter can make
difference in taste. Palak poori had a value of 20.53 ± 0.01
77
percent of crude fat. Similarly mixed vegetable pakoda had a
value of 29.94 ± 0.17 percent fat. Being deep fried product tacos
also had a higher value of crude fat i.e. 21.59 ± 0.01 percent.
The maximum quantity of crude fat was found in namkeen para
with a value of 37.69 ± 0.18 percent. Coming to the shallow fried
product namely pancake showed a value of 14.67 ± 0.03 percent
which is lower than the deep fried products. Gruel had crude fat
of 5.59 ± 0.04 percent. Addition of standard milk to the crushed
plain roti increased the fat content of this product. Fried
products provide concentrated energy.
Crude Fiber
Crude fiber content of maize based recipes ranged
from 0.95 ± 0.09 to 1.61 ± 0.01 percent. Highest content was
observed in namkeen para which was followed by methi roti and
plain roti with the values of 1.54±0.01 and 1.45 ±0.02 percent,
respectively.
Palak poori and tacos had close values of fiber viz
1.40 ± 0.02 and 1.35 ± 0.01 percent. Both of these products
were prepared using a combination of maize and wheat flour
with addition of little vegetables. Therefore these values are not
very different than that of plain roti whereas pancake and mixed
78
vegetable pakoda had still lower fiber content of 1.02 ± 0.01 and
1.10 ±0.01 percent, respectively. These products had refined
bengal gram flour along with vegetables. The minimum value of
fiber was obtained in gruel (0.95± 0.09%) as only milk and sugar
were added to crushed plain roti.
Ash
The ash content of the recipes prepared from maize
flour ranged from 0.93 ± 0.11 to 1.67 ± 0.03 percent. Plain roti,
gruel and namkeen para had lower values of 0.93 ± 0.11, 1.02
±0.01and 1.03 ± 0.01 percent, respectively. Addition of wheat
flour, vegetables and paneer resulted in maximum ash content
in tacos. Palak poori and methi roti had 1.58 ± 0.01 and 1.52 ±
0.003 percent ash, respectively. Probably the addition of wheat
flour, bengal gram flour and green leafy vegetables also
increased the ash content of both the products as compared to
plain roti. The ash content of pancakes and vegetable pakoda
did not differ much with values of 1.22 ± 0.03 and 1.12 ± 0.02
percent, respectively. Supplementation of maize flour with other
ingredients increased the ash content of all the products.
79
Carbohydrates
The carbohydrate content was calculated by adding
the values for crude protein, crude fat, crude fiber and ash and
then substracting it from 100. The carbohydrate content of
gruel, plain roti and methi roti was 81.49 ± 0.12, 82.03 ± 0.23
and
83.88
±
0.22
percent
which
are
quite
close.
The
carbohydrate content of pancake was 68.97± 0.10 percent
followed by palak poori which was 65.02 ± 0.08 percent. Tacos
and Mixed vegetable pakoda had carbohydrate content of 60.68
± 0.04 and 56.33 ± 0.13 percent, respectively. The lowest
carbohydrate content was found in namkeen para i.e. 47.05 ±
0.08 percent among all the recipes, the reason being a higher
content of fat in it. Addition of green leafy and other vegetables
decrease the total carbohydrates in the recipes based on maize,
thus making these suitable for feeding the diabetic patients.
Energy
The average energy provided by the various products
prepared from maize flour ranged between 370 to 561 Kcal.
Plain roti and methi roti had the low energy value of 382 and 383
Kcal respectively which was followed by gruel i.e 402 Kcal. On
the contrary, the energy provided by mixed vegetable pakoda
80
Table 4.3.1 Proximate Composition of Maize flour Based products on Dry Weight Basis
(Per 100 g)
S. No Product
Moisture
Crude
protein
Crude fat
Ash
Fiber
CHO
Energy
(Kcal)
1
Plain roti
4.44±0.001
9.04±0.21
2.11±0.01
0.93±0.11
1.45±0.02
82.03±0.23
383
2
Gruel
4.46±0.06
6.49±0.02
5.59±0.04
1.02±0.01
0.95±0.09
81.49±0.12
402
3
Methi roti
4.50±0.10
6.07±0.01
2.49±0.03
1.52±0.003
1.54±0.01
83.88±0.22
382
4
Palak poori
4.65±0.06
6.82±0.10
20.53±0.013
1.58±0.01
1.40±0.02
65.02±0.08
472
5
Pancake
5.32±0.001
8.78±0.01
14.69±0.03
1.22±0.03
1.02±0.01
68.97±0.10
370
6
Mix Veg Pakoda
4.70±0.08
6.81±0.03
29.94±0.17
1.12±0.02
1.10±0.01
56.33±0.13
522
7
Namkeen Para
4.19±0.10
8.43±0.01
37.69±0.18
1.03±0.01
1.61±0.01
47.05±0.08
561
8
Tacos
5.41±0.02
9.31±0.01
21.59±0.01
1.67±0.03
1.35±0.01
60.68±0.04
474
Values are mean ± S.D.
81
and namkeen para were on higher side among all the products
i.e. 522 and 561 Kcal, respectively because of high content of fat
in these recipes.
The energy provided by the recipes developed from
supplementation of maize flour with other ingredients like
vegetables was 474 Kcal in tacos and 472 Kcal in palak poori
while pancake had 370 Kcal. The fat content made all the
difference.
Amino Acid
Maize protein is low in lysine and tryptophan.
Pederson and Eggum (1983) in their balanced studies with rats
have reported that supplementation of wholemeal with lysine
and tryptophan increased the biological value of the protein and
weight gain in rats considerably. Therefore in the present study
the
effort
has
been
made
to
develop
the
products
by
incorporating other ingredients which can mutually supplement
the limiting amino acids so that a nutritious product is available
for consumption. Feria Morales and Pangborn (1983) suggested
enrichment of corn with milk solids and even cheese for
improvement in lysine and tryptophan content whereas direct
free
amino
acid
supplementation
82
of
cornmeal
for
tortilla
manufacture resulted in off–flavour and therefore adversely
affected the consumer acceptance (Mejia et al 1997). In the
present study, lysine and tryptophan are the two essential
amino acids of various products which have been analysed. The
results are being shown in table 4.3.2.
4.3.2 Available Lysine
Lysine content of maize varieties varied from 1.7 to
3.2 percent (IARI 1980). Some losses are expected to occur due
to cooking. In the present study, it has been observed that plain
roti had only 1.11 ± 0.01 g/16g N which was increased to its
maximum content of 3.97 ± 0.01 g/16g N in gruel because of
addition of milk. Methi roti had also good amount of lysine i.e.
3.17 ±0.03 g/16g N as a result of addition of chickpea flour and
fenugreek
leaves.
supplementation
of
Nti
and
maize
Plahar
based
(1995)
West
reported
African
that
traditional
weaning food with cowpea increased the lysine, tryptophan and
threonine content.
Tacos and mixed vegetable pakoda had lysine value of
2.67 ± 0.02 and 2.63 ± 0.02 g/16 g N respectively whereas the
lysine content of pancake, namkeen para and palak poori was
83
Table 4.3.2
Available Lysine and tryptophan content of maize flour based products on dry
weight basis (g/16gN)
S.No
Product
Lysine
Tryptophan
1
Plain roti
1.11±0.01
0.40±0.02
2
Gruel
3.97±0.01
0.86±0.04
3
Methi roti
3.17±0.03
1.50±0.04
4
Palak poori
1.37±0.005
3.10±0.13
5
Pancake
1.99±0.003
1.96±0.03
6
Mix Veg Pakoda
2.63±0.02
2.12±0.11
7
Namkeen Para
1.46±0.06
0.58±0.03
8
Tacos
2.67±0.02
1.91±0.01
Values are Mean ± S.D.
84
lower i.e. 1.99 ± 0.003, 1.46 ± 0.06 and 1.37 ± 0.01 g/16g N,
respectively.
4.3.3 Tryptophan
Likewise the tryptophan content was also low in
maize varieties i.e. 0.35 to 0.5 percent as reported by IARI
(1980). The tryptophan content of maize based recipes were in
the range of 0.40 ± 0.02 to 3.10 ± 0.13 g/16g N. Palak poori had
3.10 g/16g N of tryptophan content that was highest among all
the products. Mixed vegetable pakoda had 2.12 ± 0.11 g/16g N
tryptophan whereas the values were almost similar for pancake
and tacos i.e. 1.96 ± 0.03 and 1.91 ± 0.01 g/16g N. Namkeen
para had only 0.58 ± 0.03 g/16g N because its supplementation
was done with refined wheat flour and gram flour in the ratio of
3:1:1. Surprisingly the tryptophan content of gruel was almost
doubled (0.86 ± 0.04 g/16g N) than that of roti.
Minerals
Minerals are essential for the health and well being of
the body. Bones and skeleton are made up mainly of calcium
and
phosphorous.
Iron
is
an
essential
component
of
haemoglobin. Mosha et al (2000) examined six types of home
based and commercial weaning foods consumed in Tansania. All
85
the foods were deficient in calcium, iron and zinc. They
suggested the supplementation of the starchy staples with
mineral rich foods. Hence in the present study the selected
products were prepared by incorporating milk and milk products
and green leafy vegetables in maize based recipes and analyzed
for calcium, iron and ionizable iron (Table 4.3.3 and 4.3.4).
Moreover, household processing like making chapatti of maize
flour and even roasting of maize cob in a sand bath or on
charcoal improved the availability of minerals upon loss of
phytic acid on heating (Khan et al 1991).
4.3.4 Calcium
Plain roti is a very poor source of calcium with a value
of 5.49 ± 0.02 only. On dry matter basis, the calcium content of
the tacos was highest followed by gruel i.e. 187.95 ± 0.66 and
146.30 ± 0.05 mg/100g, respectively. The reason for the highest
content of calcium in tacos was due to addition of paneer
whereas in gruel the addition of milk resulted in higher value of
calcium. Methi roti also showed high value of 145.75 ± 0.85
mg/100g because of addition of fenugreek leaves. The rest of the
products had lower values for calcium like for pancake it was 57
.72 ± 0.02 mg/100g whereas the values for palak poori, namkeen
86
Table 4.3.3 Calcium content of maize flour based products on
dry weight basis (mg/100g)
S.No
Product
Calcium
1
Plain roti
5.49±0.02
2
Gruel
146.30±0.05
3
Methi roti
145.75±0.85
4
Palak poori
35.41±0.02
5
Pancake
57.72±0.02
6
Mix Veg Pakoda
30.19±0.03
7
Namkeen Para
32.88±0.02
8
Tacos
187.95±0.66
Values are Mean ± S.D.
87
para and mixed vegetable pakoda was 35.41 ± 0.02, 32.88 ±
0.02 and 30.19 ± 0.03 mg/100g, respectively which are very
close to each other.
4.3.5 Total iron
Cereals are good source of iron unless these are
refined. Maize flour contains 2.3 mg of iron per 100g while
wheat flour contains 5.3 mg per 100g. The total iron content
was increased in all products supplemented with other cereals,
legumes and vegetables except the gruel where the iron content
was only 1.16 ± 0.04 mg/100g which was less than that of plain
roti (1.26 ± 0.01 mg/100g) because of addition of only milk, a
poor source of iron but otherwise nutritious. Even Turnlund et
al (1990) also observed the absorption of iron from cereal based
diet is neither enhanced or inhibited by the addition of milk. The
maximum iron content (3.23 ± 0.02 mg/ 100g) was analysed
from palak poori which had equal proportion of wheat flour
supplemented with spinach. Tacos had 2.80 ± 0.01 whereas
methi roti had 2.59 ± 0.03 mg /100 g of iron which was more as
compared to that of plain roti. The values of iron observed in
pancake and namkeen para were quite close i.e. 2.17 ± 0.01 mg
and 2.05 ± 0.06 mg/100g. Even mixed vegetable pakoda
88
exhibited lower value for iron (1.68 ± 0.03%) because of addition
of other vegetables, which were not very good source of iron.
Nevertheless these had other advantages.
4.3.6 Ionizable iron
The values for ionizable iron ranged from 0.65 ± 0.04
mg to 2.07 ± 0.04 mg/100g. The lowest value for ionizable iron
was observed in gruel i.e. 0.65 ±0.04 mg/100g followed by plain
roti 0.78 ± 0.04 mg/100g in ascending order. Mixed vegetable
pakoda contained 0.91 mg of ionizable iron. The values for the
namkeen para and palak poori were 1.34 ± 0.03 and 1.69 ± 0.03
mg/100g, respectively whereas pancake and tacos had ionizable
iron to extent of 1.80 ± 0.65 and 1.82 ± 0.03 mg/100g. The
methi roti had highest content of ionizable iron among all the
products i.e. 2.07 ± 0.04 mg/ 100g. Surprisingly, the availability
of iron was minimum from the product i.e. palak poori where the
total iron was maximum.
On
calculating the
percent
iron
bioavailability using
equation given by Rao and Prabhavati(1978), the highest iron
bioavailability was observed in methi roti i.e.1.46 percent and
lowest in case of gruel i.e. 0.79 percent that was corresponding
to the values of ionizable iron.
89
Table 4.3.4 Total Iron, ionizable iron and percent bioavailability of maize flour based products
on dry weight basis (mg/100g)
S.No
Product
Iron
Ionizable iron
Iron bioavalability %
1
Plain roti
1.26±0.01
0.78±0.04
0.85
2
Gruel
1.16±0.04
0.65±0.04
0.79
3
Methi roti
2.59±0.03
2.07±0.04
1.46
4
Palak poori
3.23±0.02
1.69±0.03
1.28
5
Pancake
2.17±0.01
1.80±0.65
1.33
6
Mix Veg Pakoda
1.68±0.03
0.91±0.02
0.91
7
Namkeen Para
2.05±0.06
1.34±0.03
1.11
8
Tacos
2.80±0.01
1.82±0.03
1.34
Values are Mean ± S.D.
90
4.4 Cost of Maize flour Based Nutritious Products
The cost of selected seven products prepared from
maize flour has been calculated and presented in table 4.4.
It was observed that the cost per serving was
maximum for tacos (Rs 2.90) followed by methi roti (Rs 2.30)
whereas the cost of plain roti was Rs 1.10 per serving but it can
only
be
consumed
along
with
some
preparation
of
vegetable/dhal which will definitely increase its cost. The cost
per serving of other products ranged between Rs 1.40 to Rs
2.20. Addition of other ingredients like bengal gram flour and
milk and its products and vegetables obviously increased the
cost
of
the
products.
Nevertheless,
the
variety
was
also
increased.
4.5 Nutritive Value of Maize Based Nutritious Products (Per
Serving) on fresh weight basis
Moisture
The moisture content of the maize based nutritious
recipes was calculated on the basis of per serving. It was found
that the moisture content of gruel was highest i.e. 65.95 g per
serving. Methi roti and mixed vegetable pakoda had almost
similar values of 45.36 g and 42.41 g, respectively on the per
91
Table 4.4 Cost of maize flour based nutritious products (Rs per serving)
S.No
Product
Weight of one serving (g)
Cost per serving
1
Plain roti
110
1.10
2
Gruel
120
2.00
3
Methi roti
120
2.30
4
Palak poori
75
1.65
5
Pancake
75
2.20
6
Mix Veg Pakoda
100
2.00
7
Namkeen Para
30
1.40
8
Tacos
40
2.90
92
serving basis. The calculated moisture content of tacos and
palak poori was found to be close to each other i.e. 33.22 g and
31.55 g while the pancake had moisture content of 29.66 g per
serving. However, the namkeen para had the lowest value for
moisture content i.e. 3.70 g per serving.
Crude protein
The calculated crude protein value for maize products
ranged from 2.98 to 12.58 g per serving. The lowest being for
pancake and highest value for methi roti. The value of crude
protein for namkeen para was 3.55 g as compared to 2.98 g per
serving in pancake. The protein content of mixed vegetable
pakoda and palak poori was very close to each other with the
value of 6.10 g and 6.66 g per serving respectively. Tacos and
gruel had values of 7.06 g and 7.11 g of protein per serving as
compared to that of plain roti which was 8.87 g/serving. Methi
roti was found to have highest protein content of 12.58 g per
serving.
Crude fat
It was observed that plain roti had lowest content of
crude fat i.e. 2.88 g per serving. It was followed by methi roti and
gruel with values of 3.63 g and 6.13 g per serving, respectively.
93
As in case of roti no fat was used for their preparation that is
why the value of both the rotis was less than that of gruel the
value of which increased due to addition of full fat milk in the
recipe. Pancake had crude fat content of 11.22 g per serving
followed by namkeen para and tacos with the fat content of
15.94 g and 16.45 g per serving respectively. Palak poori which
was deep-fried had crude fat content of 20.11 g per serving. The
highest fat content was found in the mixed vegetable pakodas
i.e. 26.83 g per serving.
Ash
The ash content of the maize based recipes varied
from 0.43 g to 2.04 g per serving. The lowest value was for
namkeen para and the highest value was for the methi roti.
Pancake and mixed vegetable pakoda had almost similar ash
content of 0.95 g and 1.01 g per serving of the products. The
calculated value of ash content of the plain roti and gruel were
also close to each other with the value of 1.19 g and 1.12 g per
serving respectively. The product which was prepared with
supplementation of wheat flour and vegetables i.e tacos had ash
content of 1.28 g per serving while palak poori had a value of
1.56 g per serving.
94
Crude fiber
The calculated value of crude fiber was found to be
highest for the plain roti i.e. 2.15 g per serving. It was followed
by methi roti with the value of 1.83 g per serving. The products
prepared on supplementation of maize flour with wheat flour,
paneer and spinach i.e palak poori and tacos had fiber content
of 1.37 g and 1.03 g per serving. Gruel and mixed vegetable
pakoda had similar values of 0.95 g and 0.98 g per serving.
Pancake in which supplementation of maize flour was done with
bengal gram flour and other vegetables had fiber content of 0.75
g per serving while the namkeen para provided very less amount
of fiber i.e. 0.67 g per serving.
Carbohydrates
The
carbohydrate
content
of
the
eight
recipes
prepared from maize flour was also calculated on the per serving
basis.
It
ranged
from
10.66
g
to
67.89
g.
The
lowest
carbohydrate content was found in namkeen para and highest
was for the methi roti. Tacos had carbohydrate content of 16.43
g per serving whereas the pancake, gruel and palak poori had
almost equal quantity of carbohydrates i.e 22.90, 26.92, 26.92 g
per serving, respectively. Mixed vegetable pakoda had lower
95
Table 4.5 Nutritive Value of Maize flour Based Nutritious products (g Per Serving) on Fresh
Weight Basis
S.No
Product
Moisture
Crude
protein
Crude fat
Ash
Fibre
CHO
Energy
(Kcal)
1
Plain roti
11.92
8.87
2.88
1.19
2.15
52.96
273
2
Gruel
65.95
7.11
6.13
1.12
0.95
26.92
191
3
Methi roti
45.36
12.58
3.63
2.04
1.83
67.89
355
4
Palak poori
31.55
6.66
20.11
1.56
1.37
26.92
315
5
Pancake
29.66
2.98
11.22
0.95
0.75
22.90
205
6
Mix Veg
Pakoda
42.41
6.10
26.83
1.01
0.98
40.25
427
7
Namkeen
Para
3.70
3.55
15.94
0.43
0.67
10.66
200
8
Tacos
33.22
7.06
16.45
1.28
1.03
16.43
242
96
carbohydrate content (40.25 g) than the plain roti i.e.52.96 g per
serving.
Energy
The energy value was observed to be highest in case
of mixed vegetable pakoda i.e. 427 Kcal per serving which was
followed by methi roti and palak poori with energy value of 355
Kcal and 315 kcal respectively. The calculated energy content of
the tacos was found to be 242 kcal whereas pancake and
namkeen para had very close energy value of 200 kcal and 205
Kcal respectively. The least energy was provided by gruel was
191 Kcal per serving.
Lysine
The lysine content in the maize based products was
found to be highest in gruel due to the addition of milk and
methi roti also had good amount of lysine content i.e. 4.36 and
3.27 g/16 g N, respectively. Mixed vegetable pakoda and tacos
had lysine content of 2.33 and 2.03 g per 16 g N. Plain roti and
pancake had also similar values of 1.59 and 1.51 g per 16 g N,
respectively. Palak poori had lysine of 1.35 g per 16 g N whereas
namkeen para had lower amount of lysine as compared to all
other
products
i.e.
0.63
g
97
per
16
g
N
per
serving.
Table 4.5.1 Lysine and Tryptophan Content of Maize flour Based Nutritious products (g/16g
Per Serving) on fresh weight basis
S.No
Product
Lysine
Tryptophan
1
Plain roti
1.59
0.32
2
Gruel
4.36
0.80
3
Methi roti
3.27
1.98
4
Palak poori
1.35
1.37
5
Pancake
1.51
0.35
6
Mix Veg Pakoda
2.33
0.81
7
Namkeen Para
0.63
0.12
8
Tacos
2.03
0.38
98
Tryptophan
The tryptophan content of maize recipes ranged from
0.12 to 1.98 g per 16 g N per serving, the lowest being for
namkeen para and highest for the methi roti. Plain roti, pancake
and tacos had almost similar amount of tryptophan i.e. 0.32,
0.35 and 0.38 g per 16 g N, respectively. The tryptophan content
for gruel and mixed vegetable pakoda was almost equal i.e. 0.80
and 0.81 g per 16 g N per serving which was almost double the
amount present in plain roti, pancake and tacos.
Calcium
The calcium content of plain roti was very low i.e 7.99
mg per serving which was followed by namkeen para i.e. 13.91
mg. Mixed vegetable pakoda had calcium content of 26.93 mg
while palak poori and pancake had 34.67 and 44.16 mg per
serving. It was found that tacos and gruel had higher amount of
calcium i.e. 143.42 and 147.58 mg per serving due to the
presence of paneer and milk in the recipes, respectively. Methi
roti had highest calcium content of 160.6 mg per serving and if
this is served with curd, the value tends to increase further.
99
Table 4.5.2 Calcium and Iron Content of Maize flour Based Nutritious products (mg per
Serving) on fresh weight basis
S.No
Product
Calcium
Iron
1
Plain roti
7.99
1.83
2
Gruel
147.58
0.88
3
Methi roti
147.58
3.20
4
Palak poori
34.67
2.20
5
Pancake
44.16
1.43
6
Mix Veg Pakoda
26.93
1.70
7
Namkeen Para
13.91
1.93
8
Tacos
143.42
1.38
100
Iron
The iron content of the maize based recipes ranged from
0.88 to 3.20 mg per serving for gruel and methi roti, respectively.
The reason for the higher iron content of roti due to presence of
fenugreek leaves. The iron content for tacos and pancake was
found to be 1.38 and 1.43 mg per serving, respectively. The
value for the iron content in case of mixed vegetable pakoda,
plain roti and namkeen para was found to be close i.e. 1.70, 1.83
and 1.93 mg per serving, respectively. Palak poori also showed a
good amount of iron content in it i.e. 2.2 mg per serving.
4.6 Evaluation of protein quality of products
The NDpCal% of the maize flour based products has
been given in Table 4.6. The results revealed that NDpCal% of
methi roti improved to 8.5 as compared to 5 of plain roti which
further improved to 9.5 when curd was added to it whereas
addition of milk increased the NDpCal% of gruel to 8.5. Similarly
addition of Bengal gram flour and curd did improve the
NDpCal% of pancake to 7.5 while the addition of cottage cheese
in tacos improved the NDpCal% to 8. Namkeen para had
NDpCal% of 5 only inspite of addition of bengal gram flour but
due to high content of fat total energy percent was high.
101
Similarly high fat content of mixed vegetable pakoda and palak
poori may be held responsible for lowering the value of NDpCal%
than that of roti.
From the organoleptic evaluation of the eight maize
based recipes it was concluded that pancake got highest score
and was highly acceptable (8.6 ± 0.49) among all the products.
On the dry weight basis, it was found that tacos had highest
moisture, protein, ash and calcium content. The crude fat was
found to be highest in case of namkeen para. Methi roti had
highest carbohydrate and fiber content and the maximum
energy was provided by mixed vegetable pakoda (561 Kcal). The
total iron was observed to be maximum in case of palak poori
(3.23 ± 0.02%) and ionizable iron in tacos (1.82 ± 0.03%). The
lysine and tryptophan content was found to be highest in case of
gruel and palak poori, respectively.
On fresh matter basis, it was found that moisture
content was highest in gruel, crude protein and ash in methi
roti, crude fat in mixed vegetable pakoda, crude fiber and
carbohydrate in plain roti. The maximum energy was provided
by mixed vegetable pakoda with the value of 427 Kcal and
minimum by gruel i.e. 191 per serving.
102
Table 4.6 Protein, Calories, amino acid and NDpCal % of the recipes
S.No
Recipe
N(g)
Calories
Amino acid
NDpCal%
1
Plain roti
1.77
342
0.35
5
2
Gruel
1.26
230
0.41
8.5
3(a)
Methi roti w/o curd
4.52
809
1.18
8.5
3(b)
Methi roti
6.88
973
2.17
9.5
4
Palak poori
6.04
2008
1.21
3.2
5
Pancake
5.71
1296
2.08
7.5
6
Mix Veg Pakoda
6.13
1646
2.14
1.5
7
Namkeen Para
4.31
1197
1.17
5
8
Tacos
11.4
2456
4.28
8
103
Calcium and iron content was found to be highest in case of
methi roti i.e. 160.60 and 3.20 mg/ serving respectively. It was
observed that tacos had maximum lysine (5.09 g/16g N
/serving) and methi roti had maximum amount of tryptophan
(1.65 g /16g N /serving).
From the evaluation of cost of maize based recipes on
per serving basis it was found that cost of tacos (Rs 2.90
/serving) was maximum as compared to the other supplemented
maize products.
From the organoleptic evaluation of the seven maize
based recipes it was concluded that pancake got highest score
and was highly acceptable (8.6 ± 0.49) among all the products.
On the dry weight basis, it was found that tacos had highest
moisture, protein, ash and calcium content. The crude fat was
found to be highest in case of namkeen para. Methi roti had
highest carbohydrate and fibre content and the maximum
energy was provided by mixed vegetable pakoda (561 Kcal). The
total iron was observed to be maximum in case of palak poori
(3.23 ± 0.02%) and ionizable iron in tacos (1.82 ± 0.03%). The
lysine and tryptophan content was found to be highest in case of
gruel and palak poori, respectively.
On fresh matter basis, it was found that moisture
content was highest in gruel, crude protein and ash in methi
roti, crude fat in mixed vegetable pakoda, crude fiber and
carbohydrate in plain roti. The maximum energy was provided
by mixed vegetable pakoda with the value of 427 Kcal and
minimum by gruel i.e. 191 per serving.
Calcium and iron content was found to be highest in
case of methi roti i.e. 160.60 and 3.20 mg/ serving respectively.
It was observed that tacos had maximum lysine (5.09 g/16g N
/serving) and methi roti had maximum amount of tryptophan
(1.65 g /16g N /serving).
From the evaluation of cost of maize based recipes on
per serving basis it was found that cost of tacos (Rs 2.90
/serving) was maximum as compared to the other supplemented
maize products.
The nutritive value of maize flour based nutritious
recipes has been given in annexure II on per 100 g on fresh
weight basis and scoring of all the recipes has been given in
annexure III.
105
CHAPTER – V
SUMMARY AND CONCLUSIONS
The present study was conducted on the ‘Sensory and
nutritional evaluation of recipes based on maize flour. Eight
recipes were prepared using maize flour supplemented with
other ingredients which were locally available in the market.
Most commonly used recipes were prepared namely plain roti,
methi roti, mixed vegetable pakoda and palak poori. In addition
to these pancake, gruel, namkeen para and tacos were also
prepared. These products were prepared so that common people
can easily adopt them. These were prepared in the laboratory
using simple cooking practices normally followed at home. The
maize based products were evaluated organoleptically by a panel
of judges from the faculty of the Department of Food and
Nutrition using nine-point hedonic scale. These products were
dried and then analysed for proximate composition, total iron,
ionizable iron, calcium, lysine and tryptophan. The values for
maize based recipes on fresh weight basis were also calculated
using Nutritive Value of Indian Foods. The cost of the maize
based recipes was also calculated on per serving basis.
106
Organoleptic evaluation revealed that pancake had
highest score for all the parameters i.e. colour (8.4 0.49),
appearance (8.3  0.46), aroma (8.1  0.30), texture (8.5  0.50),
taste (8.7  0.46) and overall acceptability (8.6  0.41). The score
above eight depicts that pancake was liked very much. The
overall acceptability score for methi roti was lowest as compared
to other recipes i.e. 7.3  0.64. The gruel got average score of 7.2
 0.60 for appearance and aroma and for taste and overall
acceptability it was 7.6  0.66 and 7.6  0.49, respectively. Plain
roti earned maximum scores in appearance and taste (8.0 
0.45) and for overall acceptability the score was 7.9  0.3. The
mixed vegetable pakoda and tacos got similar score for overall
acceptability i.e. 8.1  0.54.
The moisture content of the selected recipes ranged
from 4.19 to 5.41 percent. The lowest value was observed for the
namkeen para and highest for the tacos. The crude protein
content of all the developed recipes ranged from 6.07 to 9.31
percent minimum value being in pancake and maximum in
tacos.
There was wide variation in crude fat content on dry
weight basis in selected maize based products. It ranged from
107
2.11  0.01 percent in plain roti to 37.69  0.18 percent in
namkeen para. Crude fat content of plain roti and methi roti was
less as no fat was smeared on them. Gruel had little higher
amount of crude fat. Values of crude fat for other deep fried
products also increased in case of palak poori (20.530.01%),
tacos (21.590.01%) and mixed vegetable pakoda(29.940.11).
Highest crude fibre content was observed in methi roti
(1.54  0.01%) while lowest content was found in namkeen para
(0.910.01%) among all the eight products.
The ash content of the products ranged from 0.93 ±
0.11 to 1.67 ± 0.03 percent for plain roti and tacos, respectively.
Addition of vegetables and paneer resulted in maximum ash
content in tacos. The ash content of pancakes and vegetable
pakoda did not differ much with values of 1.22 ± 0.03 and 1.12
± 0.02 percent, respectively.
The carbohydrate content of all the recipes varied
from 47.75 ± 0.08 to 83.88 ± 0.20 percent, minimum being in
namkeen para and maximum in methi roti. The
average
energy
provided by the various products prepared from maize flour
ranged between 382 to 561 Kcal. Plain roti and methi roti had
the low energy value of 382 and 383 Kcal, respectively. The
108
energy provided by mixed vegetable pakoda and namkeen para
were on higher side among all the products i.e. 522 and 561
Kcal, respectively because of high content of fat in these recipes.
Plain roti had very low amount of calcium with a
value of 5.49 ± 0.02 only. On dry matter basis, the calcium
content of the tacos was highest (187.95 ± 0.66 mg/100g)
followed by gruel (146.30 ± 0.05 mg/100g). The rest of the
products had lower values for calcium like for palak poori ,
namkeen para and mixed vegetable pakoda i.e. 35.41 ± 0.02,
32.88 ± 0.02 and 30.19 ± 0.03 mg/100g, respectively.
The total iron content of gruel was low (1.16 ± 0.04
mg/ 100g). The maximum iron content (3.23 ± 0.02 mg/ 100g)
was found in palak poori which had equal proportion of wheat
flour supplemented with spinach. The values for ionizable iron
ranged from 0.65 ± 0.04 mg to 2.07 ± 0.04 mg/100g minimum
being in gruel and maximum in methi roti.
Plain roti had only 1.11± 0.01 g/16g N lysine that was
increased to its maximum content of 3.97 ± 0.01 g/16g N in
gruel because of addition of milk. The tryptophan content of
maize based recipes was in the range of 0.40 ± 0.02 to 3.10 ±
109
0.13 g/16g N, lowest being in plain roti and maximum in palak
poori.
On fresh matter basis, the moisture content of gruel
was highest i.e. 65.95 g and the namkeen para had the lowest
value of 3.70 g per serving. The calculated crude protein value
for maize products ranged from 2.98 to 12.58 g per serving. The
lowest being for pancake and highest value for methi roti. It was
observed that plain roti had lowest content of crude fat i.e. 2.88
g per serving. Palak poori, which was deep-fried, had crude fat
content of 20.11 g per serving. The highest fat content was
found in the mixed vegetable pakodas i.e. 26.83 g per serving.
The ash content of the maize based recipes varied
from 0.43 g to2.04 g per serving on fresh matter basis. The
lowest value was for namkeen para and the highest was for the
methi roti. The calculated value of crude fibre was found to be
highest for the plain roti i.e. 2.15 g per serving while the
namkeen para provided very less amount of fibre i.e. 0.67 g per
serving. The lowest carbohydrate content was found in namkeen
para (10.66 g/serving) and highest was for the methi roti (67.89g
/serving). The energy value was observed to be highest in case of
110
mixed vegetable pakoda i.e. 427 Kcal per serving and the least
energy was provided by gruel (191 Kcal per serving).
The calcium content of plain roti was very low i.e 7.99
mg per serving which was followed by namkeen para i.e. 13.91
mg. Methi roti had highest calcium content of 160.6 mg per
serving. The iron content of the maize based recipes ranged from
0.88 to 3.20 mg per serving being minimum for gruel and
maximum for methi roti. The reason for the higher iron content
of roti was the presence of fenugreek leaves. Palak poori also
showed a good amount of iron content i.e. 2.2 mg per serving.
The lysine content in the maize based products was
found to be highest in gruel i.e. 4.36 g/16 g N per serving. Methi
roti also had good amount of lysine content i.e. 3.27 g/16 g N
whereas
namkeen
para
had
lowest
amount
of
lysine
as
compared to all other products i.e. 0.63 g per 16 g N per serving.
The tryptophan content of maize recipes ranged from 0.12 to
1.98 g per 16 g N per serving, the lowest being for namkeen para
and highest for the methi roti.
The calculated cost per serving was maximum for
tacos (Rs 2.90) followed by methi roti (Rs 2.30) whereas the cost
111
of plain roti was only Rs 1.10 per serving. The cost per serving of
other products ranged between Rs 1.40 to Rs 2.20.
The NDpCal% of the maize products ranged from 1.5
to 9.5 percent lowest being for mixed vegetable pakoda and
highest for methi roti when curd was added to it.
Intervention
children
who
had
diets
that
were
significantly more diverse than the maize based Malawian diets
consumed higher (p<0.05) protein, calcium, zinc, haem iron,
vitamin B12 and animal foods than controls. (Yeudall et al 2005).
112
CONCLUSION
1. Pancake was highly acceptable among all the recipes.
ON DRY MATTER BASIS:
1. It was found that tacos had highest crude protein, ash and
calcium content.
2. Namkeen para had highest crude fat content.
3. Methi roti had highest amount of crude fat and ionizable iron.
4. Mixed vegetable pakodas provided maximum energy.
5. The total iron was observed to be maximum in palak poori.
6. Lysine and tryptophan content was found to be highest in
gruel and palak poori respectively.
ON FRESH MATTER BASIS (PER SERVING),
1. It was observed that moisture content was highest in Gruel.
2. Methi roti had highest amount of crude protein, ash, calcium,
iron and tryptophan content.
3. Mixed vegetable pakodas provided highest crude fat and
energy.
4. It was found that plain roti also provided higher crude fiber
and carbohydrate content.
5. Lysine was found to be highest in tacos.
113
6. The cost of tacos on per serving basis was maximum as
compared to other maize based products.
7. The NDpCal% was found to be maximum for methi roti with
curd.
Recommendation

By supplementing the maize flour with Bengal gram flour,
green leafy and other vegetables and milk and milk
products, the nutritional quality of maize flour based
products can be improved as well as a variety can be added
to the normal diet to create interest in consumption of
maize flour.

Since maximum crude fat was present in namkeen para
with minimum moisture in this resulting in longer shelf life
of this snack. Another feature of this was highest crude
fiber and lowest carbohydrate content being a concentrate
source of energy can be recommended for children.

Mixed vegetable pakodas become crisp with improved
colour when 50 percent of Bengal gram flour is replaced by
maize flour. This will bring down the cost also.

The nutritional value of plain roti can be definitely
improved by supplementing it with 20 percent Bengal gram
114
flour and fenugreek leaves. It had higher amounts of
calcium, iron, lysine and tryptophan though the protein
content was less. The taste can be improved by addition of
fat /butter.

Tacos and pancakes being nutritious can be served as
complete meal.

Gruel can be prepared from even left over roti, which is
tasty, nutritious and easily digestible.

Replace one-fourth part of maize flour with Bengal gram
flour in methi roti for better protein quality and serve it
with curd for maximum health benefit.

In palak poori, Bengal gram flour, wheat flour and maize
flour could be mixed in the ratio of 1:1:2, which will
improve NDpCal%.

Deep-frying does add to the taste of food but overall
protein quality of the product is lowered because of high
content of fat, which provides empty calories. Therefore,
frying of maize products should be done sparingly.
115
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