Fruits & vegetables are an important nutritional requirement of human beings as these foods not only meet the quantitative needs to some extent but also supply vitamins & minerals which improve the quality of the diet & maintain health. Fruit, vegetables & oil seeds processing is one of the pillars of the food & edible oil industry. India is the second largest producer of both fruits and vegetables. Fruits and vegetables are the reservoir of vital nutrients. Being highly perishable, 20 to 40% of the total production of fruits and vegetables goes waste from the time of harvesting till they reach the consumers. It is, therefore, necessary to make them available for consumption throughout the year in processed or preserved form and to save the sizeable amount of losses. At present, about 2% of the total produce is processed in India mainly for domestic consumption. Fruits and vegetables have great potential for value addition and diversification to give a boost to food industry, create employment opportunities and give better returns to the farmers. Oil seeds also play an important role in the food sector & daily life. Edible oils constitute an important component of Indian households. Domestic edible oil consumption in India is increasing. Self sufficiency in edible oils today stands at in recent years, availabilities of non conventional oil, rice bran oil, soybean oil, palmolein oil and cottonseed have increased. Oils are essential components of all plants. However, commercial oil production facilities only utilize plants that accumulate large amounts of oil and are readily available In order to improve the nutritional status of the people & also to exploit the export potential of processed products there is need to increase the productivity of processed food in the country. Currently, India accounts for 7.0% of world oilseeds output; 7.0% of world oil meal production; 6.0% of world oil meal export; 6.0% of world veg. oil production; 14% of world veg. oil import; and 10 % of the world edible oil consumption.
Some of the fundamentals of the book are preservation of pineapple, mango and papaya chunks by hurdle technology, effect of boiling on beta-carotene content of forest green leafy vegetables consumed by tribals of south India, process development for production of pure apple juice in natural colour of choice, physical refining of rice bran and soybean oils, anti nutrients and protein digestibility of fababean and ricebean as affected by soaking, dehulling and germination, quality changes in banana (musa acuminata) wines on adding pectolase and passion fruit, essential oil composition of fresh and osmotically dehydrated galgal peels, development of cold grinding process, packaging and storage of cumin powder, bakery products and confections, etc.
This book deals completely on the basic principles & methodology of fruits, vegetables, corn & oilseed processing & its preservation. This will be very resourceful to readers especially to technocrats, engineers, upcoming entrepreneurs, scientists, food technologists etc.
Chapter 1 : Preservation of Pineapple, Mango and
Papaya Chunks by Hurdle Technology
Chapter 2 : Process Development for Production of
Pure Apple Juice in Natural Colour of Choice
Chapter 3 : Anthocyanins from Indian Varieties of Grapes
Chapter 4 : Processing Effect on Colour and Vitamins
of Green Leafy Vegetables
Chapter 5 : Dissipation of Alphametherin Residues
in/on Brinjal and Tomato During Storage
and Processing Conditions
Chapter 6 : Effect of Boiling on Beta-carotene Content
of Forest Green Leafy Vegetables Consumed
by Tribals of South India
Chapter 7 : Physical and Functional Properties of
Mucilages from Yellow Mustard (Sinapis alba L.)
and Different Varieties of Fenugreek
(Trigonella foenum-graecum L.) Seeds
Chapter 8 : Quality Parameters of Selected Mango Cultivars
Chapter 9 : Effect of Stage of Apple Pomace Collection
and the Treatment on the Physico-chemical
and Sensory Qualities of Pomace Papad
Chapter 10 : Physical Refining of Rice Bran and Soybean Oils
Chapter 11 : Physico-chemical Status of Major Milk
Constituents and Minerals at Various Stages of Shrikhand Preparation
Chapter 12 : Studies on the Development of Instant
'Dahi Bhalla'-An Indian Traditional Snack
Chapter 13 : Quality Characteristics of Freeze Dried Indian
White Squid (Loligo duvauceli Orbigny)
Chapter 14 : Antinutrients and Protein Digestibility of
Fababean and Ricebean as Affected by
Soaking, Dehulling and Germination
Chapter 15 : Nutritional Evaluation of Sorghum Flour on
Supplementation with Whey Proteins
Chapter 16 : Nutritional Evaluation of Soy Fortified Biscuits
Chapter 17 : Functional Properties of Defatted Cashew
Chapter 18 : Glucoamylase Production by Aspergillus Niger
in Solid State Fermentation
with Paddy Husk as Support
Chapter 19 : Effect of Storage on Physico-chemical &
Nutritional Characteristics of Carrot-Beetroot
and Carrot-Black Carrot Juice
Chapter 20 : Osmotic Dehydration Characteristics
of Button Mushrooms
Chapter 21 : Quality Changes in Banana
(Musa acuminata) Wines on Adding Pectolase
and Passion Fruit
Chapter 22 : Concentration of Clarified Orange Juice by
Chapter 23 : Studies on the Volatiles of Cardamom
Chapter 24 : Effect of Level of Juice Extraction on
Physico-chemical Characteristics and
Bitterness of Heat Processed Kinnow Juice
Chapter 25 : Nutritive Value of Malted Flours of Finger
Millet Genotypes and Their Use in the
Preparation of Burfi
Chapter 26 : Effect of Storage on Rice Yield Recovery
Chapter 27 : Studies on the Processing and Evaluation
of Instant Idli Mixes
Chapter 28 : Vermicelli Noodles and Their
Chapter 29 : Composition and Functional Properties
of Fermented Soybean Flour (Kinema)
Chapter 30 : Biscuit Making Quality of Advance Lines of
Wheat in India
Chapter 31 : Effect of Incorporation of Defatted Soyflour on
the Quality of Sweet Biscuits
Chapter 32 : Effect of Supplementation of Processed Maize
Germ Cake on Nutritional Quality of Maize
Chapter 33 : Studies on the Stability of Some Edible Oils
and Their Blends During Storage
Chapter 34 : Reversed-Phase HPLC of Methyl Esters of
Fatty Acids in Soybean Oil
Chapter 35 : Functional Properties and Nutritive Composition
of Maize (zea mays) as Affected by Heat
Chapter 36 : Effect of Non-enzymatic Browning on Quality
of Lime Juice
Chapter 37 : Essential Oil Composition of Fresh and
Osmotically Dehydrated Galgal Peels
Chapter 38 : Solar Drying of Coriander and Methi Leaves
Chapte 39 : Supercritical Co2 Extraction of Sesame Oil
from Raw Seeds
Chapter 40 : Studies on Juice Extraction of Aonla
(Emblica officinalis Gaertn.) cv. 'Chakaiya'
Chapter 41 : Anti-nutritional and Flatulence Factors at Various
Stages of Vegetative Growth of Fenugreek
(Trigonella Foenum Graecum L.) Leaves
Chapter 42 : Processing and Quality Evaluation of Banana
(Musa acuminata) Cheese
Chapter 43 : Effect of Primary Processing on Microbial
Load of Cauliflower and Fenugreek
Chapter 44 Utilisation of Peel in Plantain Wine Production
Chapter 45 : Optimization of Processing Conditions for
Cottage Scale Production of Hurum
Chapter 46 : Sugarcane Juice Concentrate
Preparation, Preservation and Storage
Chapter 47 : Nutritive Value of Dehydrated Green Leafy
Chapter 48 : Optimization of Process Parameters for
Absorption of Milk by Makhana
Chapter 49 : Development of Nutritious Supplementary
Biscuits from Greengram Dhal
Chapter 50 : Vitamin A Fortification of Cottage Cheese
Chapter 51 : Biochemical Composition of Cashew
(Anacardium occidentale L.) Kernel Testa
Chapter 52 : Microbiological Quality of Milk, Vegetables
and Fruit Juices
Chapter 53 : Bacteriological Examination of Pasteurized Milk
and Milk Products, Sold in Harare, Zimbabwe
Chapter 54 : Effect of Different Thermal Treatments on
Vitamin C and Microbial Sterility of Canned
Drumstick (Moringa oleifera)
Chapter 55 : Solar Tunnel Drying of Red Chillis
(Capsicum annum L.)
Chapter 56 : Studies on Nitrogen Extractability of Defatted
Chapter 57 : Development of Cold Grinding Process,
Packaging and Storage of Cumin Powder
Chapter 58 : Determination of Residual Hexane and
Microbiological Status in De-oiled Soybean Meal
Chapter 59 : Oilgosaccharide Levels of Processed
Redgram (Cajanus cajan L.)
Chapter 60 : Impact of Drying on Quality of Betel Leaf
(Piper betle L.)
Chapter 61 : Chemical Composition, Anti-nutritional
Factors and Shelf-life of Oyster Mushroom
Chapter 62 : Effect of Milk Protein Modification on
Physico-chemical Changes During Ripening
of Cheddar Cheese
Chapter 63 : Simple Tests for Differentiating Raw-Old and
New and Steamed Rice in a Mixture
Chapter 64 : Effect of Chhana and Paneer Whey on the
Manufacturing Time and Loaf Volume of Bread
Chapter 65 : Glucose Lowering Effects of Pre-cooked
Instant Preparations Containing Alfalfa Seeds in
Non-insulin Dependent Diabetic Subjects
Chapter 66 : Modelling of Visual Shelf-life of Pearl Millet
(Pennisetum glaucum) Dough (Fura)
Chapter 67 : Effect of Blanching on Pickled Bitter Gourd
Chapter 68 : Testing of A Convection Type Cylindrical Dryer
for Production of Instant Soy dosa Mix
Chapter 69 : Antinutrient Profile and Chemical Composition
of Custard Powder Produced in Nigeria
Chapter 70 : Evaluation of Performance of Shea Fat as
a Shortening in Breadmaking
Chapter 71 : Microbiological and Biochemical Changes
During Fermentation of Kanji
Chapter 72 : Bakery Products and Confections
Chapter 73 : Adverse Reactions to Food Additives
Chapter 74 : Inhibitory Action of Cinnamon on Listeria
Monocytogenes in Meat and Cheese
Chapter 75 : Competitive Growth of Aeromonas
Hydrophila in Meat
Chapter 76 Preliminary Physico-chemical and Microbial
Evaluation of an Exudate from a Neem Tree
(Azadirachta Indica Juss.) in Mysore, South India
Preservation of Pineapple, Mango and
Papaya Chunks by Hurdle Technology
stability of minimally processed products can be enhanced by using a
combination of treatments such as blanchingosmo-dehydration, addition
of chemical preservatives, modification of pH and appropriate
packaging. This technology is known as Hurdle Technology. The different
treatments called as hurdles are used in preventing the chemical as
well as microbiological deterioration of the food product. A
combination of these hurdles is very effective, while individually each
hurdle is ineffective in protecting food from deterioration.
technology has also been used for the preservation of minimally
processed fruit slices. A combination of mild heat treatment, reduction
of water activity, lowering of pH and addition of potassium sorbate and
sodium bisulphite for producing shelf stable pineapple slices was
reported by Alzamora. High moisture products from peach, pineapple,
mango, papaya, chicozapote and banana treated with a combination of
mild heat treatment, water activity reduction, addition of
antimicrobials and packed in glass flasks or high density polyethylene
bags with syrup containing preservatives, had a shelf stability ranging
from 4 to 8 months. They observed that pineapple slices blanched in
saturated vapour for 2 min, cooled in water and immersed in a glucose
syrup containing 150 mg/kg sodium bisulphite and 1000 mg/kg potassium
sorbate were acceptable up to 120 days of storage.
However, in all these studies, the fruit chunks
were stored in syrup containing high concentrations of preservatives.
The usage of covering syrup not only increases the bulk but also
increases the cost of the product. Therefore, there is a need to
explore the possibility of preserving fruit chunks of tropical fruits
such as pineapple, mango and papaya in a cost effective method. The
main objective of the present investigation was to study the effect of
different barriers or hurdles viz. osmo-blanching, reduction of pH,
addition of preservative and vacuum packaging on the shelf stability of
fruit chunks of pineapple, mango and papaya packed in polypropylene
pouches, without covering syrup.
Materials and Methods
Mature, firm ripe pineapples, mangoes (C. V. 'Neelum'), and papayas
were procured from the local fruit market, washed, manually peeled,
cored and cut into I inch x 1 inch x 0.5 inch dimensions. The cut fruit
chunks were used for different treatments. 200Brix
[a] and 40Brix [b] sucrose syrup with 0.2% citric acid at 850C
for 5 min using 1:2 fruits to syrup ratio. The blanched fruit chunks
were further dipped in 200
Brix syrup containing 0.2% citric acid, 340 mg potassium
metabisulphite/kg and 413 mg sodium benzoate/kg for 8 h at ambient
temperature, drained and packed in 150 gauge polypropylene pouches and
pineapple and mango chunks stored. at 20C
were analysed at 0. 30 and 60 days for the chemical, microbiological
and sensory qualities.
papaya fruit chunks were blanched in 400Brix
syrup containing 0.6% citric acid at 850C
for 5 min. The blanched fruit chunks were then dipped in 400Brix
syrup at 270C
containing 0.6% citric acid, 680 mg potassium metabisulphite/kg and 826
mg sodium benzoate/kg for 8 h. The chunks were drained and packed in
polypropylene pouches with and without vacuum, using vacuum sealing
machine. The pouches were withdrawn at 30, 45, 60 and 90 days storage
and analyzed for chemical and microbiological qualities.
: Moisture, total solids, reducing sugars, total sugars and carotenoids
were analyzed as per the procedure described by Ranganna. pH was
measured using a digital pH meter, Model No. APX 175, Control Dynamics,
Bangalore, India. Sulphur dioxide content of the sample was distilled
in the presence of acid in an inert atmosphere and absorbed by Iodine,
which converts sulphurous acid to sulphuric acid and titrated against
standard sodium thiosulphate solution. The S02
was reported as free and combined. The sample was saturated with NaCr
solution and neutralized by excess NaOH. The benzoic acid present in
the sample was converted into water soluble sodium benzoate, the
solution was acidified with excess HCI, water insoluble benzoic acid
was formed, and extracted with chloroform. The chloroform was removed
by evapouration and the residue containing benzoic acid was dissolved
in alcohol and titrated against standard NaOH.
: The samples were assessed for colour, flavour, texture and overall
quality by a 15 member trained panel on a 10 point scale, where 1-2 =
poor, 3-4 = fair, 5-6 = good, 7-8 = very good, and 9-10 = excellent.
Samples receiving an overall quality score of 7 or above were
considered acceptable and those receiving below 7 were considered
unacceptable. The sensory data were subjected to two way analysis of
variance and the difference between the means was analyzed by Duncans
multiple range test.
aerobes, yeasts and molds were enumerated using plate count and
coliform numbers by the most probable number technique.
Results and Discussion
pHs of mango and papaya fruit chunks got reduced to below 4.0 after the
syrup treatment as compared to the pH of fresh chunks (Table 1). The reduction of pH and
penetration of sugar into the treated fruit chunks also improved the
sensory quality by establishing sugar acid ratio in addition to the
preservative effect. King
also observed that reduction of pH in case of fruits having a pH of 4.5
and above also functioned as an effective hurdle in improving the shelf
stability of minimally processed products.
Lower pH caused unfolding of the protein molecule by
disruption of the hydrogen bonds, thereby reducing the enzyme activity
and increasing its sensitivity to denaturation. There was no
significant change in pH in all the treatments during storage. The S02,
concentration in the treated pineapple and mango chunks ranged from 65
mg/kg to 80 mg/kg and the, benzoic acid from 150 mg/kg to 200 mg/kg.
The treated papaya chunks had higher amount of SO2
(135 mg/kg) and benzoic acid (135 mg/kg).
case of papaya where initial total soluble solids content was very low
Brix the syrup treatment improved colour, flavour and acceptability. The pH of the fruit slices
adjusted to 3.5-3.8 had not effected the natural taste of the product.
of storage on chemical changes in pineapple chunks:
Reducing sugars of the pineapple chunks showed a steady increase during
storage in both [a] and [b] treatments after 30 days and 60 days
storage and the increase was found to be maximum in the samples stored
(Table 2). This
could be explained by the higher rate of inversion under acidic
conditions at high temperature. There
were no significant differences in total sugars in both the treatments
stored at 20C
and 270C. The retention of total
carotenoids was found to be maximum in the samples stored at 20C,
indicating the adverse effect of temperature on the samples stored at 270C. A marginal increase in
total solids was observed in 60 days storage of both the treated
samples, which could be due to the loss of moisture during storage.
of storage on chemical changes in mango chunks:
Reducing sugar contents of mango chunks stored at 270C
increased during storage. Total
carotenoid contents decreased in the mango chunks stored at 270C,
whereas, there were no significant changes in the samples stored at 20C,
indicating better storage stability at low temperature. The changes in
total sugars were not appreciable. Total solids content increased
marginally during storage, indicating loss of moisture (Table 2).
of storage on microbiological quality of pineapple chunks :
Pineapple chunks subjected to the blanching treatment of (a] and stored
for 30 and 60 days showed mesophilic aerobic counts of 640 and 1000
cfu/g, respectively. In
case of chunks subjected to treatment [b], the count was 500 cfu/g both
at 30 and 60 days of storage at 270C.
There were significant increases in yeast and mold counts after 60 days
of storage in both [a] and [b] treatments (Table 3).The pineapple
chunks had an acceptable quality up to 30 days storage at 270C.
Coliform count was found to be negative in all the treatments of
pineapple chunks during the entire period of storage.
Alzamora also reported that pineapple slices preserved by
combined methods and stored for 4 months at 270C
exhibited no growth of microrganisms during 30 days storage. The lower microbial growth
rates in their study could be due to the higher level of preservatives
used and packing the fruit slices along with the syrup containing
contents of papaya chunks decreased with increase in temperature (270C)
during storage. It was a first order reaction rate constant 'k'. The
reaction rate (k) was higher at higher temperature, indicating faster
degradation of carotenes at 270C than at 20C.
Also, the product packed under vacuum had lower
degradation of carotenes, as compared to ordinary packing. This might
be due to the fact, that carotene was more sensitive to oxygen in the
storage atmosphere (Fig. 2).
studies have indicated the effect of storage conditions in particular
temperature and the method of packing, on the changes in the reducing
sugars and carotenes during storage. By determining the 'k' value, the
rate at which these quality parameters deteriorate over the storage
period can be evaluated. To retain the maximum nutrients, appropriate
conditions can be applied.
of storage on microbial quality of papaya chunks: Microbial study
during 3 months storage at 270C indicated no significant growth of
microorganisms, indicating the stability of the product during storage. The aerobic counts
increased marginally at 60 days storage and decreased at 90 days
storage. There was no growth of yeast and mold and coliform count was
found to be negative during the entire period of storage (Table 6).
Guerrero reported that aerobicplate count increased by two logarithmic
cycles and then decreased, reaching values similar to initial one
during storage of banana puree by combined methods.
of storage on sensory quality of papaya chunks: Table 7 shows the
overall quality of papaya chunks during storage. Two way ANOVA
indicated significant differences among the treatments at the end of 30
days storage. The
overall quality of papaya chunks packed without vacuum was
significantly superior to other treatments. The vacuum-packed papaya
had slightly lower overall quality scores as compared to papaya chunks
packed without vacuum because of leaching of juice and partial
softening of the tissue during vacuum packing.
The papaya chunks packed without vacuum and stored at 20C
had superior overall quality, followed by the papaya chunks stored at
270C. The overall
quality ratings reduced at the end of 90 days storage but the papaya
chunks were still acceptable.
reported blanched papaya slices equilibrated in syrup for 3 days with
continuous circulation of syrup packed along with the syrup containing,
pH 3.5, 1000 mg potassium sorbate/kg and 150 mg sodium bisulphite/kg in
the 'glass jars had a storage life of 5 months at 250C.
The longer storage life in their study was attributed to
the higher level of preservatives and packing of slices along with the
all the earlier reported studies involving the preservation of fruit
slices by combined methods, the fruit slices were packed with syrup
containing preservative either in glass flasks or high density
polyethylene pouches. The
fruit slices were also blanched with saturated steam before the
in the present study, the fruit chunks were blanched in sugar syrup,
followed by a dip in syrup containing preservatives. The significance
of blanching in sugar syrup was to inactivate the enzymes, reduce
microbial load, as well as partial reduction in water activity due to
osmotic dehydration during syrup treatment. The flavour of the fruit
chunks can also be retained during osmo blanching as compared to the
steam blanching where volatile flavour compounds may be lost. The
preservative levels in the treated fruit chunks are also comparatively
lower than those reported in earlier studies.
may be concluded that pineapple and mango fruit chunks, blanched in
syrup at 850C for 5 min, dipped in syrup containing 340 mg potassium
metabisulphite/kg and 413 mg sodium benzoate/kg for 8 h and packed in
150 gauge polypropylene pouches have a shelf life of up to a period of
30 days at 270C and 60 days at 20C, whereas the papaya chunks treated
with increase in level of preservatives 680 mg potassium
metabisulphite/kg and 826 mg sodium benzoate/kg have exhibited good
storage stability up to 90 days at. 20C and ambient temperature.
Development for Production of Pure Apple Juice in Natural Colour of
always prefer food material free from any chemical preservative or
additive. This is especially true in case of food products like fruit
juices which are expected to be additive free and close to natural
a limited survey in the local markets of Mumbai, it was observed that
many additives including preservatives and colour were being used in
apple juice. These additives many times would mar the natural quality
of juice mainly the taste and appearance. This observation prompted to
develop a process in which use of any additive was completely
eliminated, while at the same time retaining the colour and other
attributes in their original form to the maximum possible extent.
juice can be preserved in very pure state without having any additive
in it. Its colour also can be controlled by regulating the enzymatic
browning of the juice. The regulation is achieved by physical
techniques. In these techniques, the enzymatic browning reaction is
temporarily avoided by extracting the juice in the absence of oxygen,
under inert atmosphere of nitrogen, which is immediately followed by
permanent prevention of the reaction by inactivation of the polyphenol
oxidase by thermal energy. Since in apple juice, colour development is
due to enzymatic browning and to some extent leaching of colour from
skin into juice, regulation of the two phenomena was attempted. The
technique developed was very effective in controlling colour of apple
juice, as a result of which, the juice could be obtained as a drink in
three different colours, free from any additive in it.
Materials and Methods
Apples mainly 'Red
delicious' available in Mumbai were used in this study. In few trials a
small sized variety locally known as 'Saharangpur' variety were also
used. The apples were stored at 0-40C
A juicer, Mixer, Grinder Model No HL 3298 [Philips (India) Ltd.] was
used to extract juice.
Under normal conditions, when juice is extracted from apple, it
instantly turns brown due to enzymatic reaction.
When this juice is bottled, the final product gets a brown
Fig. 1 shows the laboratory
scale experimental set up to preserve apple juice, in three different
colour shades, without adding any external ingredient to it. The above unit had
capacity to process 10-kg apples per hour to produce 5 liters of apple
juice and pomace, which after drying can yield 1.5kg dry apple powder.
limiting factor of this unit was that the capacity of compartment
collecting the waste material and sedimentation of fine powdery
sediments in juicer assembly, causing obstacle to rapid discharge of
juice from juicer housing into outlet duct. Due to this, after
processing of 4 kg, the debris and sediments were removed and the
process was restarted.
overcome the phenomenon of enzymatic browning, the air inside the
juicer was replaced with nitrogen and an inert atmosphere was
maintained in the juicer throughout the period of operation. Such situation was
achieved by modifying the open outlet duct of the juicer by covering it
with detachable a box type cover termed as an attachment having a
nozzle fitted to it at the base. The
attachment was designed and fabricated from 'Perspex' sheets. The
attachment can easily be attached to or detached from the juicer outlet
duct simply by pushing or pulling.
Once the attachment was fixed, air could not enter through
the juicer outlet duct as long as a positive pressure of nitrogen gas
existed inside the juicer.
tubing of 1/32" ID and 3/32" OD well fitting into the hole, were
inserted through the two holes provided on the attachment to introduce
nitrogen gas into the attachment and juicer.
attachment was connected to hot water bath through the flexible PVC
tubing. The upper
end of the PVC tubing is connected to the nozzle of the attachment,
while the other end to the SS tubing passed through the hot water bath.
of flushing air inside the juicer with nitrogen:
Nitrogen gas was distributed using a 5-point gas distribution tubing as
detailed in Fig. 1. Using this device, nitrogen was introduced at four
critical points A, B, C and D as depicted in the figure. This ensured
complete nitrogen atmosphere at i) just below the cutter sieve disc of
the juicer ii) inside the attachment iii) just above the cutter sieve
disc and iv) at the base of waste material collection chamber.
: The function of this unit was to increase apple juice temperature in
shortest possible time. The drop of juice just after release from apple
tissue entered into heat exchanger and before coming out of the unit it
instantly attained a temperature of 80 - 850C. Polyphenol oxidase (PPO),
which catalyses oxidation of phenol leading to browning got totally
inactivated and the juice never turned brown.
hot water bath consists of a thin walled cylindrical tank of 26 cm
inside diameter and 26 cm height.
A thermostatically regulated heating coil was provided at
the center of the circular base (Fig. 1).
steel tubing of 6 mm inside diameter, 0.1(thickness having 5 meter
length was rolled into a helical. The coil was having 25 cm mean
diameter of the helical with a descending slope, 5 cm per turn. The total turns 5 in
number. The two ends of the SS tubing were brought about 10 cm through
the wall of the cylindrical tank..Whilef upper end was connected to the
attachment, the lower was connected to a similar tank through which
chilled was circulated instead of the hot water.
water bath :
This water bath was identical in do to the hot water bath but having no
heating coil and cooling coil was shorter in length.
This bath was meant to down the juice to a temperature
The juice coming out from the chilled bath, contained some amount of
fine particles which need to be filtered out.
In laboratory scale, because of volume, the juice was
first filtered through cheesecloth remove coarse particles, followed by
removal of very fine particles by centrifugation.
: The clear juice thus obtained was filled under nitrogen in 200 ml
capacity bottles. The bottles were sterilized by keeping them in
boiling water for 15 min. Storage
of the bottles at room temperature did not show any microbial growth.
of brown pigment formed in apple juice and measurement of degree of
Apple juice was extracted and kept in presence of air until brown
colour was developed. The juice was centrifuged to remove insoluble
solids and the spectrum of the brown pigment was recorded against the
reference prepared as follow. Apple
juice was extracted from the same lot of apples in absence of air or
oxygen. The juice
was collected in a conical flask (with stopper) flushed with nitrogen
and containing pre-weighed quantity of the antioxidant sodium
erythorbate to bring the final concentration to 25 mM. The clear
solution obtained after centrifugation was used as a reference. The
reference sample was prepared first and then the experimental.
reference sample shows 0.3 O.D. at 390 nm with respect to distilled
water. Hence, in
absence of any reference sample, browning of apple juice was measured
by its absorbance at 390 nm with reference to distilled water minus 0.3.
of the temperature required for inactivation of PPO
: About 50-60 ml of apple juice was quickly extracted and collected
under nitrogen in a stoppered conical flask having a thermometer and
sample withdrawing arrangement. Immediately
after extraction the flask was quickly transferred in boiling water
bath. Samples (3
ml) were withdrawn from the flask at regular time intervals after
noting its temperature at the time of withdrawing.
The sample under test was transferred in a test tube kept
in a water bath at 300C
After allowing the full development of brown colour the test sample was
centrifuged and the OD of the brown pigment formed in the clear fluid
was read against distilled water at 390 nm using a Shimatzu
: The three varieties of apple juice prepared in laboratory along with
sample of two well known commercial brands of apple juice procured from
local market were simultaneously served under stipulated conditions to
a taste panel containing 36 judges. The above five apple juice test
samples were simultaneously evaluated for five characteristics namely,
appearance, colour, flavour, taste and overall acceptability on a
9-point Hedonic scale.
: The product can be obtained in three colour shade (1) Brown (2)
Slightly pink and (3) Pale yellow, the natural shade of apple juice.
browning is to be eliminated, the attachment is placed at its proper
nitrogen carrying tubes were inserted properly up to the points A, B, C
and D as shown in Fig. 1. Processing was initiated by switching on the
hot water bath and raising the temperature of water in it to 95-960C. Once the required
temperature was attained nitrogen gas was flushed vigorously for about
1 or 2 min, till the air inside the juicer space is flushed out
this stage was reached, the flow rate of nitrogen gas was reduced to
such a level, which was just sufficient to maintain some positive level
in the juicer so that no air from outside entered into the space inside
juicer. Once such
conditions were established, apples (stored either in freezer at 0-400C
or at room temperature) were cut one by one into pieces of the size,
which could enter in the juicer. Within
a minute or shorter time after cutting, the pieces were crushed in
juicer after removing the seeds with help of knife or scoop so that
there was very little chance for browning to occur.
the juice got released from tissues by the action of speedily rotating
cutter sieve, the same was collected in juice collecting compartment
filled with nitrogen. Because
of non-availability of oxygen in it, browning reaction could not
proceed and due to the slope in juicer housing, the juice automatically
flowed under gravity and fell in the juicer attachment then through
nozzle of attachment, into the inlet port of the hot water bath. As it started flowing due
to gravitational force through the helical tubing submerged under water
its temperature started increasing very rapidly with its further
juice entered hot water bath it came out of it in just 30-40 sec with
its temperature being increased from 300C
Because of non-availability
of small size, constant flow rate pump, gravitational force was
utilized to circulate juice through the heat exchanger.
However, pump was a better choice.
hot water bath was designed in such a way that juice once entered in
it, flowed continuously without resting in between, and under steady
conditions, when juice was continuously fed without any break, the
temperature of the juice coming out from outlet port would not deviate
from 80-850C. The hot juice was cooled
while passing through chilled water bath.
of tube in water baths: After completion of operations, water was
flushed through tubing which removed all deposits inside the tubing. Holding hot NaOH solution
in the SS tubing for some time, followed by flushing with water could
carry out harsh cleaning, whenever found necessary.
powder: Apple waste left after juice extraction was dried in an oven at
the dry mass was pulverized and then passed through a screen of proper
Results and Discussion
2 shows the spectrum of the brown pigment formed when apple juice is
exposed to air, showing the maximum absorbance at 390 nm.
residual PPO caused brown pigment formation in the juice after keeping
it at 3O0C
vs the highest temperature to which the juice was subjected during
heating treatment to inactivate PPO. Mono phenol and diphenolases (PPO)
have been reported to be quite heat stable. Temperature reported here
was in full agreement with the data presented.
Based on this study, the hot water bath was designed in
such a way that under normal operating conditions where juice was
expected to flow uninterruptedly at a rate of about 80-90 ml per min,
each drop of juice attained a temperature of 80-850C
before coming out of the outlet.
various steps involved in processing apple juice to preserve it in
three different colour shades. The brown shade of the juice was mainly
due to enzymatic browning and to some extent due to the colour leached
out from the peel. The
leached colour subsequently changed its shade due to heat during
sterilization process. The
colour due to non-enzymatic browning during sterilization also got
added to it and thus final shade was formed.
pinkish coloured apple juice lacked totally the enzymatically formed
brown pigment in it. However, it contained the colour that was leached
out from peel into juice (which changed its shade during sterilization)
and colour, which developed due to non-enzymatic reactions during
third category juice lacked both the enzymatic, formed brown pigment
and the pigment, which got extra from peel. The pale but bright colour
of the juice was due to natural shade of apple tissue fluid with slight
red tinge, which got added due to the non-enzymatic brown, taking place
during sterilization. The three samples could stored at room
temperature but low temperature was prefer for a longer shelf life.
The data on organoleptic evaluation of the three products stored for
three months at 40C,
along with two-apple juice samples of known common brands are presented
in Table 1.
far as the appearance and colour were concerned (, two apple juice
types brown and pinkish scored the same points as those of market
sample 1 (MKS-1) and market sample 2 # (MKS-2).
The third type the apple juice in its natural colour,
scored marginally less than MKS-2.
However, all three varieties of apple juice scored between
6 and 7 between the quality mark "Good" and "below good but all fair"
on the Hedonic scale. With respect to the characteristic flavour, apple
juice in which browning was allowed showed highest score among all the
samples, followed by coloured, the natural coloured juice and then
MKS-1 with little margin. However,
MKS-2 showed very low score compared with the scores of the four
elimination of enzymatic browning reduced the score with respect to
flavour from 7.49 to 6.63 and further for elimination of phenolic
constituents, which were associated with peel, by the action of removal
of peel reduced the score further down 6.63 to 6.53. Here the loss in
flavour could be due to the one extra heat treatment apart from
sterilization the pinkish and the natural coloured juices were undergo
for PPO inactivation. Apple is rich source of phenol compounds (90-100 Mg/l00g). These
compounds include catachin, pyrocyanidin, epicatechin, 4-methyl
catechol, phenolchlorogenic acid, naringin and rutin.
The latter two concentrated in peel. The obtained suggest
the possibility of involvement of compounds and the associated browning
reaction development of flavour. PPOs
and phenolic compounds known to be involved in development of flavour
during coffee processing and in potato.
is the most crucial characteristic and all the varieties under test
showed the score around and above 7('Good') on the Hedonic scale,
whereas the market samples were lacking this quality as the scoring was
5.97 (MKS-1) and 4.6 (MKS-2). Many
panalists felt that the market apple juice samples were sour in taste,
especially (MKS-2) was too much acidic although the claim on was 100 %
natural. All the
three test samples were far better than the two market samples with
respect to taste.
a result, in respect of the overall acceptance, the highest, score was
shown by the brown coloured juice (7.22), followed by pinkish sample
(6.75), followed by the natural coloured juice (6.51), then MKS-1 (6.2)
the least accepted was MKS-2 (4.78). MKS-1 contains lot of additives
including caramel colour while MKS-2 has been labelled as 100 % pure
and 100% natural.
the three-apple juice samples prepared in our laboratory, the best
sample was the brown coloured juice, followed by pinkish one and the
last the natural coloured apple juice. However, all these samples were
superior to the two market samples MKS-1 and MKS-2 mainly due to taste
and flavour. They were not in any way significantly inferior to the
market samples with respect to the appearance and colour.
Anthocyanins from Indian Varieties of Grapes
comprise the largest group of naturally occurring pigments, which are
responsible for the red, blue, purple, violet and magenta colouration
of most species in the plant kingdom.
Notable exceptions are tomatoes and beets, which owe their
red-orange and red-purple colouration to the pigments, lycopene and
betanin, respectively. These polyphenolic substances are glycosides of
anthocyanidins; which are polyhydroxy and polymethoxy derivatives of
benopyrrillum or flavylium salts. The large numbers of glycosyl and
acyl groups, which may bind to six different naturally occurring
anthocyanins, have contributed to more than 225 different anthocyanin
owe their attractive red to purple colouration to these water-soluble
the colouring matter of grapes is found only in the cells of the skin
and is a good source of anthocyanins.
Grape pomace is a relatively inexpensive source of
anthocyanins, since it is a by-product of the wine industry.
grape pomace has been reported to be useful in preparation of
carbonated beverage with 0.168 mg/ml of anthocyanins. In another
report, stability of anthocyanin in model squash and juice systems was
studied. The physico-chemical evaluation with respect to berry weight
and juice volume, Brix, total acids, soluble acids and sugar rate has
been studied in Indian varieties of grapes.
Since there are no reports in literature on identification
of anthocyanin in Indian varieties of grapes, the present studies were
undertaken to identify the same in Indian grapes.
Materials and Methods
used for the analysis of anthocyanins were procured from the
Agricultural Products Marketing Committee Market, Navi Mumbai, India.
652, a weakly acidic cationic exchange resin, an equivalent of
Amberlite IRC 50 was procured from Ion Exchange (p) Ltd., Mumbai, India. All other chemicals were
of Analar grade procured from Sisco Research Labs, Mumbai, India.
skin was separated from the fruit, and washed with water to remove
adhering matter. The
grape skin was blended with 0.1% conc.
HCI in methanol in a Waring blender. The mixture was left
for 15 h at 100C. It was then filtered
through Whatman No. 1 filter paper, using a Buchner funnel. The residue was extracted
repeatedly with the same solvent until the extract became colourless. The combined filtrates
were concentrated using a Rotary vacuum evapourator (vacuum 700 mm,
The extract was purified by passing through weakly acidic ion exchange
resin, Indion 652 using the method described by Fuleki.
The total anthocyanin content was calculated using the formula :
x 529 x 1/L expressed with respect to malvidin -3-glucoside, the major
pigment found in grapes.
- Molar extinction co-efficient of malvidin -3-glucoside = 28,000 M.W.
of malvidin -3-glucoside = 529, L, path length = 1 cm, A = absorbency.
purified concentrate was subjected to descending chromatography on
Whatman No. 3 filter paper. The
solvent system used was butanol: acetic acid: water (4:1:5). Each run took 15 h. The
paper was air-dried and each band was cut. The pigment on the band was
eluted with methanol: acetic acid: water (85:5:5) into 0.1% HCI in
fraction was concentrated using rotary vacuum evapourator followed by
nitrogen flushing. This concentrate was then used for identification of
anthocyanins. For this, the different experiments included (a) spectral
analysis, (b) chromatographic mobility, (c) determination of the sugar
rnoiety, (d) aglycone, (e) acyl group.
Table 1 shows the solvent systems used for the extraction of the
hydrolysis of anthocyanin:
To about 2.0 mg pigments in methanol, 2.0 ml of 2N HCI was added and
placed in a boiling water bath. An
aliquot was withdrawn at 5-min. and spotted on TLC plate. This test distinguishes
the type of glycosides.
The pigment (about 1.0 mg in 2.0 ml. methanol) was hydrolysed with) 2.0
ml of 2N HCI as described above. The
mixture was cooled and the aglycone extracted with 1 ml of amyl alcohol. The aqueous phase was
extracted thrice with 1.0 ml of 10% di-N octyl methylamine in
chloroform to remove traces of HCI.
Finally, traces of amines were removed by extraction with
1.0 ml of chloroform. The
sugar solution was dried in a water bath and dissolved in a drop of
water. The sample
was spotted along with authentic sugars (glucose, galactose, arabinose,
rhamnose and xylose). The
paper was developed with BBPW. The
chromatogram was air-dried and visualised by spraying with aniline
hydrogen phthalate followed by heating at 1050C
for 5 min.
amyl alcohol solution containing the aglycone was spotted on Whatman
No. 1 papers or TLC plates and developed independently with solvent
systems for aglycone detection.
moieties: To 1.0 mg pigment in 1.0 ml methanol,1.0 ml of 2N
NaOH was added. The test tube was flushed with nitrogen; closed and
left at 300C
(room temperature) for 2 h. The mixture was neutralised with 1.5 ml of
2N HCI. For
extraction of the acyl moiety, the mixture was extracted thrice with
ethyl ether using 2.0 ml each time and evapourated with nitrogen
flushing. The residue was dissolved in a few drops of ether and spotted
on Whatman No. 1 papers along with authentic compounds (p-coumaric,
ferulic and caffeic acid). The
papers were developed independently with BAW and 2% acetic acid. The air-dried
chromatograms were visualised under UV light at 254 and 366 nm.
The absorption spectra of anthocyanins and anthocyanidins were measured
in 0.1% HCI containing methanol using the Genesys 5 UV-Visible
containing 0.1% HCI was used as blank. The AICI3shift
was measured by recording the spectrum after addition of 3 drops of 10%
in 95% ethanol.
layer chromatography: This was carried out using
20 x 20 cm glass plates with precoated 0.2 mm thick layer of cellulose
plates were heated at 1200C
for 15 min, before use for activation.
Chromatograms were developed in solvent systems.
spectra of pigments:
The absorption maxima of the individual pigments in the visible and
ultra violet regions were measured in methanol with 0.1% HCI (Tables 4,
5 and 6). It has been reported that (O.D at 440 nm/visible maximum) of
5-substituted anthocyanin was approximately half of the corresponding
anthyocyanin in which the 5-hydroxyl group is free. The ratio provides
a means of distinguishing between 3- and 3,5- diglucosides. In the
present study in pigments of 'Sharad seedless' extract it was observed
that these values for monoglucosides were much higher as compared to
of the glucose moiety resulted in reduction in ratio as can be seen
with 3,5 diglucoside (46%) and the feruloyl derivative (30%) (Table 4.)
Additional peak at 310-325 nm has been reported to indicate the
presence of acyl group. This was observed in acylated anthocyanins of
'Sharad seedless' extract.
in visible lmax
with few drops of AICl3
indicated presence of ortho dihydroxyl groups as seen in Tables 4 and 5
for derivatives of delphinidin, and cyanidin.
This was, however, not as prominent in pigments of 'Sharad
in the different extracts, it was observed that there was no shift in
visible lmax for malvidin derivatives as reported earlier.
hydrolysis of anthocyanins:
On partial hydrolysis, it was possible to distinguish monoglucosides
from diglucosides. In
pigments of 'Sharad seedless', which were acylated, the acyl groups
separated from the pigments and could be observed under UV with Rf
greater than 0.95 in the solvent systems used for identification of
Identification of aglycones was carried out by comparison of Rf
in different solvent systems with reported values. In 'Kalisahebi'
extract the Rf
values for anthocyanidins were comparable to reported values in
Forestal solvent system. The Rf
values for anthocyanidins in 'Sharad seedless' were comparable to
values reported in Formic and Forestal solvents systems. However, in
case of 'Pinot Noir' extract the Rf
values for anthocyanidins did not correspond exactly with reported
While glucose was the only sugar found in 'Kalisahebi' and 'Pinot Noir'
grapes, 'Sharad seedless' grapes contained rhamnose also as sugar group
genetic relationship among V. vinifera with regard to anthocyanin
pigments in grapes has been discussed.
It has been concluded that V. vinifera varieties contain
only monoglucosides of anthocyanidins. The present study indicates that
'Sharad seedless' variety of grapes is a hybrid variety since
diglucoside anthocyanins were present in the extract.
1 of 'Sharad seedless' extract contained no acyl or sugar group. It can therefore be
concluded that the pigment was the aglycone derived from pigment 2.
This band was found to be in very low concentration (Table 4) also
indicating that it could be the degradation product of pigment 2.
Physical and Functional Properties of
Mucilages from Yellow Mustard (Sinapis alba L.) and Different Varieties
of Fenugreek (Trigonella foenum-graecum L.) Seeds
starch and gelatin have been used to provide the desired textural
properties to foods. Large
scale processing technology places greater demands on the thickeners
and gelling agents employed. Recently,
mucilaginous substances from oilseeds (mustard, canola and flax) and
fenugreek seeds have shown to possess polymerase rheological behaviour
of gummy substances. These mucilages are known to have certain
functional properties in food applications such as thickeners,
emulsifiers, stabilizers and foaming agents.
the several sources of mucilages the seeds of fenugreek (Trigonella
foenum-graecum L.), a leguminous herb, commonly cultivated as fodder
and condiments as well as for culinary and medicinal purpose, seems to
be a potential source of mucilaginous substance.
India ranks first in the production of fenugreek; during
the year 1997-98 India produced about 40000 tonnes of fenugreek. This
occupies the third place in area and fourth place in production among
the spices grown in India.
occupies first position in the world, both with regard to acreage and
production of rapeseed and mustard. In India, the Brassica crops occupy
the second largest position after groundnut, with 7.06 million
hectares, producing about 7.2 lakh tonnes of seeds annually.
it is pertinent to exploit the use of mucilages from the seeds of
fenugreek and yellow mustard. This may help in promoting new food
additive and result in increased economic incentives to producers
besides helping in by-product utilization and value addition to food.
Materials and Methods
: The seeds of yellow mustard (Sinapis alba L) were procured from Crop
Research Centre, Govind Ballabh Pant University of Agriculture and
: The fenugreek (Trigonella foenum-graecum L.) seeds of eleven
varieties, namely 'Kasuri methi', 'Lam Selection', 'PFg'S-1', 'Pusa
Early Bunching' (PEB), 'RMT-1', 'UM-11', 'UM-22', 'UM-23', 'UM-33',
'UM-34', and 'UM-77' were procured from Horticultural Research Centre, Pattharchatta,
Govind Ballabh Pant University of Agriculture and Technology, Pantnagar.
Analytical grade reagents were used.
extraction from the seeds of yellow mustard and fenugreek:
The method of Cui was standardized for the extraction of mucilage from
seeds of yellow mustard and fenugreek.
The seeds were dispersed in boiling water (1: 10 w/v for
yellow mustard and fenugreek). The
dispersion was incubated at 750C
for 25 min, followed by stirring on a magnetic stirrer for 12 h at 230C
and the dispersion was filtered through muslin cloth.
Mucilage was precipitated from filtrate by adding 95%
alcohol (1 : 1 v/v). Precipitated
mucilage was either stored in refrigerator at 40C
or oven dried at 450C,
followed by grinding and finally storage at room temperature (250 10C).
The yield of mucilage was calculated for selecting the highest yielding
Specific gravity of the mucilage aqueous solutions (0.1 and 1% w/v) was
determined at 200C
using specific gravity bottle. The
pH of the mucilage solution in distilled water (0.1 and 1% w/v) were
determined using a digital pH meter. Viscosity of mucilage solution in
distilled water (0.1 and 1% w/v) was determined by Brookfield
Synchrolectric Rotary Viscometer (Model LVT) using appropriate spindle. The corresponding factor
was noted from the standard table to convert the dial reading to centi
(Cp) = Dial reading of meter * speed factor
: Water holding capacity was determined according to the method of
Quinn. Fat binding capacity was determined by the method described by
Lin. Emulsion activity and emulsion stability, as the indices of
emulsifying properties, were measured by the modified method of Cui.
Whipping properties were measured by the method of Yatsumatsu,at They
were expressed as foam expansion and foam stability.
Solubility was determined using the method described by MA.
analysis : Data
were analysed for ANOVA as described on factorial Combined Randomised
: Mucilage yield from yellow mustard and different varieties of
fonugreek is presented in Table 1. Effect of variety on mucilage yield
was highly significant (P