Experiment # 1 Aim: Preparation of makhan (Desi Butter)davjalandhar.com/dbt/fst/SOP-Lab Manual/BFST...

FST – 401 (Processing of milk products-I) of 8

Experiment # 1

Aim: Preparation of makhan (Desi Butter)

Requirements: Fresh cream, Beater, Utensils, Chilled water

Theory: The cream is agitated and during agitation air is incorporated. The incorporation of air in

cream increases viscosity of cream. This result the fat globules closed to each other. On further

agitation, these fat globules adher to each other to form butter granules and there is change in

emulsion from oil in water (cream) to water in oil (butter).

Procedure:

1. Take weighed amount of cream in a clean utensil.

2. Beat the cream with the help of a beater.

3. Beating/agitation is continued until small butter granules are formed.

4. Add chilled water (break water) to cream to bring down the temperature of the content.

5. Beating is continued until the granules attain pea size.

6. The butter milk is drained off and the butter granules are washed and worked together.

7. The percentage yield of butter is calculated as per formula.

Formula:

Weight of makhan x 100

Makhan (desi butter) (%) =

Weight of cream


Experiment # 2

Aim: Preparation of ghee from makhan

Requirements: Fresh cream, utensils, chilled water, beater, heater, ladle, sieve

Procedure:

1. Fresh makhan is prepared from cream by its churning.

2. This makhan is placed over fire. During initial heating of makhan, excessive frothing takes

place which must be controlled carefully to avoid losses.

3. As moisture evaporated and frothing decreasing, the temperature begins to rise above 100°C.

4. When temperature reaches 110°C, a slight caramalization of curd particle is noticed.

5. The heating is discontinued as soon as curd particles attain light brown color.

6. After this clarified fat is decanted off.

7. The ghee obtained is weighed and percentage yield is calculated.

Formula:

Weight of ghee x 100

Ghee (%) =

Weight of makhan


Experiment # 3

Aim: Preparation of ghee from cream

Requirements: Heater, beaker, ladle, utensils, sieve, fresh cream

Procedure:

1. The cream is placed over fire and during initial heating of cream, excessive frothing takes place

which must be controlled carefully to avoid losses.

2. As moisture evaporated and frothing decreasing, the temperature begins to rise above 100°C.

3. When temperature reaches 110°C, a slight caramalization of curd particle is noticed.

4. The heating is discontinued as soon as curd particles attain light brown color.

5. After this clarified fat is decanted off.

6. The ghee obtained is weighed and percentage yield is calculated.

Formula:

Weight of ghee x 100

Ghee (%) =

Weight of cream


Experiment # 4

Aim: To study ripening of cream

Theory: The term ripening of cream refers to the fermentation of cream which is intended for butter

manufacture. The process is also called souring of cream. The most common bacterias used as starter

culture for ripening of cream are:

· Streptococcus lactis

· Streptococcus cremoris

· Streptococcus diacetylactis

· Leuconostoc citrovorum

The bacteria in butter culture are of two types:

1. One that has the function of fermenting the lactose of milk to produce lactic acid which in

turn coagulates the milk. Streptococcus lactis and Streptococcus cremoris carry out this function

2. The other group of bacteria i.e. Streptococcus diacetylactis and Leuconostoc citrovorum

attack principally the citric acid content of the milk and produce volatile acid and diacetyl which

provides desirable flavor and aroma to butter.

Procedure:

1. Cream is pasteurized at 82°C for 30mins and cooled to 22°C.

2. This cream is inoculated with starter culture at the rate of 0.5-1%.

3. Then this cream is incubated at 22°C for 8-10 hrs during which fermentation of cream take

place and there is development of acidity accompanied by characteristic flavor and aroma. This

cream is used for churning to make butter.

4. The acidity of cream before ripening as well as after ripening can be checked by titration with

N/10 NaOH solution using phenolphthalein as indicator.

Formula:

Titre Value x Normality of NaOH x 90 x 100

Acidity (%) =

(in terms of lactic acid) Weight of sample x 1000


Experiment # 5

Aim: Determination of moisture content in a given sample of butter

Requirements: Butter sample, Petri plates, Desiccator, Weighing balance

Theory: Butter is water in oil emulsion in which fat is present in continues phase. BIS specifications

of butter are:

· Fat Not less than 80%

· Moisture Not less than 16%

· Salt Not more than 2.5%

Procedure:

1. Take 5gms of sample in a clean, dry and pre-weighed Petri plate.

2. Put the Petri plate along with sample in a hot air oven at 100°C for a particular time (2hr).

3. After particular time, take out Petri plate from oven and place it in a desiccator for about

15mins to cool.

4. Then take the weight of Petri plate along with dry sample.

5. Calculate percentage moisture content as per formula.

Formula:

Weight of moisture content x 100

Moisture Content (%) = Weight of sample

General Calculation:

Weight of empty Petri plate: W1 (g)

Weight of Petri plate + Sample: W2 (g)

Weight of Petri plate + Dry Sample: W3 (g)

(W3 - W2) x 100

Moisture Content (%) = (W2 – W1)


Experiment # 6

Aim: To study neutralization of cream

Requirements: Thermometer, neutralizer, weighing balance, burette, 0.1N NaOH, beaker, cream

Theory: The acidity of cream is expressed as percentage of lactic acid and the excess acidity in

cream is neutralize with help of suitable neutralizer (sodium hydroxide, sodium carbonate, sodium

bicarbonate). The optimum acidity of cream for butter making ranges from 0.20-0.30%.

Procedure:

1. The cream sample is mixed carefully taking care that churning of cream does not takes place. If

cream is thick, then warm it to about 30°C.

2. Take 10gms of sample in beaker.

3. Titrate it with N/10 NaOH solution using phenolphthalein as indicator.

4. Calculate acidity of cream.

5. Excessive acidity in cream is detected and optimum amount of neutralizer is added to cream to

neutralize the excessive acidity of cream.

6. Take the sample and check the acidity again as per step 2 and 3.

Formula:

Titre Value x Normality of NaOH x 90 x 100

Acidity (%) =

(in terms of lactic acid) Weight of sample x 1000


EXPERIMENT#7

Aim: To study cream separation methods

Principle: The basic principle of cream separation is based on the fact that milk fat is lighter that the

skim milk portion. At 16°C, the average density of milk fat is 0.93 and skim milk is 1.036. Hence,

when milk fat, which may be considered to be a mixture of fat and skim milk, is subjected to either

gravity or a centrifugal force, the two components i.e. cream & skim milk, by virtue of their differing

densities, separate from one another.

Methods:

1. Gravity Method: When milk is allowed to stand for some time, there is tendency of fat to rise. The velocity or

rate at which the fat globule rise is given by following equation which is known as Stoke’s Law:

V = 2G/9 {(ds-df)r²}/ n

Where,

V = velocity or rate at which a single fat globule rises.

G= Acceleration due to gravity.

ds= density of skim milk.

df= density of fat

r= radius of fat globule

n= viscosity of skim milk

From Stoke’s law it is observed that, Velocity is increased by:

a) Increase in radius of fat globule.

b) Increase in difference in densities of skim milk and fat.

c) Decrease in viscosity of skim milk.

2. Centrigugal Method:

When milk enters the rapidly revolving bowl of the cream separator, it is immediately

subjected to a tremendous centrifugal force, which is 3000-6000 times greater than the gravitational

force. When both the fat and skim milk are subjected to the centrifugal force, the difference in

densities effects the heavier portion i.e. skim milk more intensely than the lighter portion i.e. cream.

Thereby the skim milk is forced to the periphery while the cream milk towards the centre. The skim

milk & cream both form vertical walls within the bowl and are separated by being led through

separate outlets.

Stoke’s law applied to centrifugal separation is as follows:

V = r² {(ds-df)/ n} * N² * R * K


Where,

V = velocity or rate of movement of single fat globule.

N= speed of the bowl

ds= density of skim milk.

df= density of fat

r= radius of fat globule

n= viscosity of skim milk

R= Distance of fat globule from the axis of rotation.

K= Constant

FST – 403 (F & V Processing) Page 1 of 12

FST – 403 (Fruits & Vegetable Processing)

List of Practical:

1. To study drying of food products by hot air oven and sun drying

2. Cut out analysis of canned product

3. To carry out re-hydration test (dried peas)

4. To prepare lemon juice

5. Preparation of lemon pickle

6. Preparation of tomato puree

7. Preparation of tomato sauce or ketchup

8. To determine salt content in tomato sauce using Mohr method or direct titration

method

9. To determine acidity of fruit juice

10. Preparation of Apple jam


Experiment # 1

Aim: To study drying of food products by hot air oven and sun drying.

Requirements: Oven, trays, knife, beaker, potassium metabisulphite

Sample: Potato, cauliflower, peas

Theory: Drying is the phenomenon of removing adequate moisture from food product. It is

done either by sun or by oven drying method. During sun drying, there is no control

temperature, humidity and air velocity. Thus sun drying occurs naturally whereas in oven

drying, it is done under controlled conditions.

Drying is an important method of food preservation by removing moisture from it. The

moisture is removed to such an extent that there should be no growth of microbes and rate of

deterioration slow down. Drying also reduces weight and bulk of food material which helps in

reduction of packaging and storage requirements. Thereby reduces the transportation cost. Sun

drying is a slow process and is not suitable for high quality products. This is generally used to

lower moisture content to 15% or below. It requires considerable space and a food being

exposed is subjected to contamination and such products will have no storage stability as

compared to the one which is artificially dried. The artificially dried product has final moisture

content in the range of 1-15% and has storage stability at room temperature for a year or longer.

When they reconstituted by adding water, they are very close to the original food material used

during preparation.

Procedure:

Preparation of Sample

Cauliflower:

1. Wash, remove stalks, covering leaves and stems.

2. Break flowers apart into pieces of suitable size.

3. Blanch for 4-5 mins.

4. Immerse in 1% KMS solution for 1hr and drain.

Peas:

1. Wash, remove shell and collect grains.


3. Immerse in 0.5% KMS solution and drain.

Potato:

1. Wash, peel and cut into 10mm thick slices.


3. Immerse in 0.5% KMS solution and drain.

Sun Drying

a. Take appropriate sample and weigh it.

b. Spread the sample on clean, dry tray and expose it to sunlight.

c. Allow it to dry for removal of moisture to a desired extent.

d. After the completion of drying, note down the weight of dried product.

e. Calculate percentage moisture content.

Oven Drying


a. Take appropriate sample and weigh it.

b. Spread the sample in clean, dry tray and place it in pre heated oven at 100°C for an

appropriate time.

c. After completion of drying, note weight of sample and calculate percentage moisture

content.

Formula:




Weight of Sample: W1 (g)

Weight of Dry Sample: W2 (g)

(W1 - W2) x 100

Moisture Content (%) = W1


Experiment # 2

Aim: Cut out analysis of canned product

Requirements: Canned product, physical balance, vacuum gauge, can opener, sieve,

refractometer, measuring cylinder

Procedure:

1. Note the external conditions of can such as body dents or scratches, leakages around

seams, conditions of ends etc. in describing the condition of ends, use the following terms:

a. Flat: A can where both ends are concave, the vacuum is high enough to maintain the

ends of a can in concave condition.

b. Flipper: A can in which the vacuum is so low that mechanical stroke wills produce

distortion of one or both ends.

c. Springer: A can in which one end is distorted and the other end is flat and pressure

on the convex end will cause the flat end to spring out when pressed.

d. Swell: A can in which both ends are convex i.e. in which there is sufficient pressure

to cause permanent distortion of both ends.

2. Weigh the can as such and note the gross weight.

3. Vacuum or pressure: Use a gauge which indicates both vacuum and pressure. Pierce the

hollow pointed end of the gauge through the lid of the can so that the rubber gasket makes a gas

tight seal and prevent the loss of vacuum. Moisten the rubber before applying the gauge and

pierce the can with the gauge towards one edge. Do not press too hard. The vacuum or pressure

is indicated by the needle on the dial of the gauge. Note down the vacuum in mm of Hg and

pressure in pounds.

4. Open the can with a good can opener.

5. Inspection of contents: As soon as the can is opened, note down the appearance on the

surface. Overfilling or under filling can be seen. Cloudiness in the syrup or brine or

unsatisfactory appearance of the fruits or vegetables is more frequently evident at this stage.

6. Gross head space: This is the distance from the top of the double seam to the surface of

contents of the can. Ensure that solid material is below the liquid surface before measuring.

7. Drained weight: Empty the contents of the can in such a manner as to distribute the

products evenly upon a circular sieve, which should be inclined so as to facilitate the drainage

of syrup/brine. Allow the product to drain for 5mins. Calculate the drained weight as the weight

of sieve and the contents minus the weight of dry sieve.

8. Syrup/brine examination: Note the color, clarity, and the flavor of syrup/brine.

Determine the soluble solids by using refractometer.

9. Fruit content: Note the color, taste, flavor, size, shape, any blemishes etc., if present on

the solid food product.


Experiment # 3

Aim: To carry out re-hydration test (dried peas)

Requirements: Weighing Balance, water, pan, heating unit

Theory: In reconstitution, water is added to the product which is restored to conditions similar

to that when it was fresh. This enables the product to be cooked like fresh fruits and vegetables.

All vegetables are cooked but many of the dried fruits can be used for eating just by soaking in

water.

Procedure:

1. Weigh the sample (25gms).

2. Put the sample into beaker/pan and add water to it (10 times the weight of dry product).

3. Cover the pan and bring it to boil.

4. Boil gently for 30mins.

5. Drain the sample and collect the water in a beaker and examine for any traces of soil or

sand and other foreign matter.

6. Take the weight of re-hydrated sample and also examine it for palatability, toughness,

flavor, and presence or absence of bad flavors.

7. Calculate re-hydration ratio as per formula

Formula:

Weight of re-hydrated product

Re-hydration ratio =

Weight of dehydrated sample


Weight of dried sample: A (g)

Weight of re-hydrated sample: B (g)

Re-hydration ratio = B/A


Experiment # 4

Aim: To prepare lemon juice

Requirements: Lemon, sugar, KMS, lemon squeezer, knife

Theory: Squash is an important fruit beverage which contains at least 25% of fruit juice or pulp

and 40-50% of TSS. Commercially, it also contains about 1% and 350ppm of SO2 and/or

600ppm sodium benzoate. It is diluted before serving.

Mango, orange, and pine-apple are used for making squash. It can also be prepared from

lemon, lime, bael, guava, litchi, pear, apricot, musk melon and papaya.

Procedure:

1. Take the weight of lemons.

2. Wash the lemons properly under running water and wipe the lemons to dry.

3. The lemons are cut into 2-halves and juice is extracted using squeezer.

4. Take the volume of juice extracted and calculate the required recipe.

5. Mix the sugar syrup by adding calculated amount of water and sugar. Heat the mixture to

dissolve sugar properly.

6. Filter the syrup by muslin cloth.

7. Add lemon juice and strain the prepare lemon squash.

8. Add calculated amount of KMS.

9. Now fill the squash in bottles and store.

General Recipe:

Lemon Juice: 1lt

Water: 1lt

Sugar: 2 Kg

KMS: 2.5gms

(Preservative)


Experiment # 5

Aim: Preparation of lemon pickle

Requirements: Lemon, spices

Theory: The preservation of food in common salt or vinegar is called pickling. It is one of the

most ancient method of preserving fruits and vegetables. Pickles are good appetizers and add to

the palatability of a meal. They stimulate the flow of gastric juice and thus help in digestion.

Fruits are generally preserved in sweetened and spiced vinegar, while vegetables are preserved

in salt. Salt improves taste and flavor. It hardens the tissue of vegetables and controls

fermentation.

Procedure:

1. Take the weight of lemons.

2. Wash them properly under running water and then wipe them.

3. Cut the lemons into four pieces.

4. Squeeze out the juice from 1/4th

amount of lemons.

5. Mix all the spices and salt with the juice extracted.

6. Then mix this mixture with lime pieces.

7. Fill the contents into a jar and cover with a lid.

8. Keep the jar in sun for at least 4-6 days and shake it at least twice a day.

9. Store at ambient temperature in a cool and dry place.

Recipe: Lime - 1kg

Salt - 200gm

Red chilli powder - 15gm

Cinnamon - 10gm

Cumin - 10gm

Cardamom (large) - 10gm

Black pepper powder- 10gm

Cloves (headless) - 5


Experiment # 6

Aim: Preparation of tomato puree

Requirements: Heating medium, vessel, sieve, pulper, refractometer

Theory: Medium tomato puree is defined as tomato pulp without skin/seed, with or without

added salt and containing not less than 9% of salt free tomato solids. Heavy tomato puree is

further concentrated to obtain solid content not less than 12%.

Tomato paste is defined as tomato pulp without skin/seed, with or without added salt

and containing not less than 25% tomato solids. On further concentration to 33% or more, the

tomato solid product obtained is known as concentrated tomato paste.

Procedure:

1. Take mature and fully ripe tomatoes and wash them properly.

2. Cut them into 4-6 pieces.

3. Heat in a pan for 3-5mins and grind in a pulper to get pulp.

4. Strain the pulp with the help of a sieve.

5. Cook the pulp to desired consistency.

6. Check the end point with refractometer.

7. Fill the puree in bottles or cans at 82-88°C.

8. Sterilize in boiling water followed by cooling and then store in cool and dry place.


Experiment # 7

Aim: Preparation of tomato sauce or ketchup

Requirements: Heating medium, vessel, sieve, pulper, refractometer

Theory: Tomato ketchup is made up of strained tomato juice or pulp and spices, salt, sugar,

vinegar and with or without onion or garlic. It contains not less than 12% tomato solids and

25% total solids. About 1/3rd

of sugar is added at the starting of boiling to intensify and fix red

tomato color. If whole quantity is added initially, then cooking time will increase, which will

affect the quality of product adversely. Generally, sugar content varies from 10-26%.

Salt is added towards the end of cooking process, otherwise it bleaches the color of

tomato. Salt content varies from 1.3-3.4%.

Spices are added in powder form by spice bag method. Good quality vinegar is essential

for high quality product. Tomato ketchup contains 1.25-1.5% acetic acid. It is also advisable to

add 0.025% sodium benzoate to product before bottling.

Procedure:

1. Take mature and fully ripe tomatoes and wash them properly.

2. Cut them into 4-6 pieces.

3. Heat in a pan for 3-5mins and grind in a pulper to get pulp.

4. Strain the pulp with the help of a sieve.

5. Take the weight of strained pulp and calculate recipe accordingly.

6. Cook the pulp with 1/3rd

amount of sugar.

7. Also put spice bag in pulp and press it occasionally.

8. Cook till 1/3rd

volume of pulp is obtained. Then remove spice bag after squeezing.

9. Add remaining amount of sugar and salt and continue cooking.

10. Check the end point with refractmeter.

11. Add vinegar and preservative when end point is reached.

12. Fill ketchup at 88°C into bottles.

13. Pasteurize the bottles and cool and store in dry place.

Recipe:

Tomato pulp - 1kg

Sugar - 75gm

Salt - 10gm

Chopped onion - 50gm

Chopped garlic - 5gm

Chopped ginger - 10gm

Red chilli powder - 5gm

Cinnamon - 10gm

Cardamom (large) - 10gm

Aniseed - 10gm

Cumin seed - 10gm

Black pepper - 10gm

Cloves (headless) - 5

Vinegar - 25ml

Sodium benzoate - 0.25gm/kg final product


Experiment # 8

Aim: To determine salt content in tomato sauce using Mohr method or direct titration method

Requirements: Volumetric flask (250ml), burette, pipette, titration flask, weighing balance,

funnel

Reagents: 0.1N NaOH, phenolphthalein. 0.1 N silver nitrate, 5% potassium chromate

Procedure:

1. Take 5gm of sample and add approx. 50ml water.

2. Neutralize it with 0.1 N NaOH using phenolphthalein as indicator.

3. Make a volume to 250ml in volumetric flask.

4. Mix it and filter it.

5. Take 10ml of filtrate into titration flask and add about 1ml potassium chromate as

indicator.

6. Titrate with silver nitrate solution till red brown color appears.

7. Carry out a blank titration using 10ml distilled water and 1ml potassium chromate as

indicator.

8. Calculate percentage salt content as per formula

Formula:

(sample titre – blank titre) x N of AgNO3 x volume made up x

100

NaCl (%) =

aliquot of sample taken x wt. of sample x 1000


Experiment # 9

Aim: To determine acidity of fruit juice

Requirements: Titration flask, burette, pipette, beaker, volumetric flask (250ml)

Reagents: 0.1 N NaOH, Phenolphthalein

Procedure:

1. Take 100ml of juice and make up volume to 250ml.

2. Take 10 of diluted sample in titration flask and 1-2 drops of phenolphthalein as indicator.

3. Titrate with 0.1 N NaOH till light pink color appears which should persist for at least

15secs.

4. Note the titre value.

5. Calculate percentage acidity as per formula.

Formula:

Titre x N of NaOH x eq. wt. of acid x vol made up x 100

Acidity (%) =

Aliquot of sample x volume of sample x 1000


Experiment # 10

Aim: Preparation of Apple jam

Requirements: Heating unit, pulper, pan, peeler, refractometer

Theory: Jam is a product made by boiling fruit pulp with sufficient sugar to a reasonably thick

consistency, firm enough to hold the fruit tissues in position. It can be prepared from one kind

of fruit or from two or more fruits.

Jam contains 0.5–0.6% acid and invert sugar should not be more than 40%. FPO

specifications of jam are:

TSS - 68%

Fruit juice - 45%

Procedure:

1. Take fully ripe and firm apples.

2. Wash the apples properly and remove the outer skin and seeds.

3. Make the pulp. Add water if necessary.

4. Add calculated amount of sugar.

5. Boil the mixture with continue stirring.

6. Add citric acid.

7. Check the end point by refractometer.

8. Fill hot into sterilized bottles.

9. Cool the bottles and store at dry and cool place.

Recipe:

Apple pulp - 1kg

Sugar - 750gm

Citric acid - 2gm

Water - 100ml

FST – 404 (Processing of cereals & legumes) Page 1 of 13

FST – 404 (Processing of cereals & legumes)

List of Practical:

1. Determination of moisture content in a given sample of wheat flour

2. Determination of ash content in a given sample of wheat flour

3. Determination of gluten content in a given sample of wheat flour

4. Determination of acidity or free fatty acids (FFA) in a given sample of wheat

flour

5. Preparation of cake (eggless)

6. Preparation of cake biscuits

7. Study of parboiling of paddy

8. Study of Malting of Barley

9. Study of extraction of oil from rice bran


Experiment # 1

Aim: Determination of moisture content in a given sample of wheat flour.

Requirements: Weighing Balance, Spatula, Hot Air Oven, Petri plates, Desiccator

Theory: Moisture test is useful to determine the amount of water present in wheat flour. It is

determine by drying in a hot air oven. This method consists of measuring the weight loss by

foods due to evaporation of water.

The wheat flour should be stored at a moisture content of 12-14%. If the moisture

content is more than 14%, then there are chances of microbial growth which immediately

deteriorate flour quality.

Procedure:


2. Put the Petri plate along with sample in a hot air oven at 130°C for a particular time

(1hr).

3. After particular time, take out Petri plate from oven and place it in a desiccator for

about 15mins to cool.



Formula:







(W3 - W2) x 100



Experiment # 2

Aim: Determination of ash content in a given sample of wheat flour.

Requirements: Weighing Balance, Spatula, Muffle Furnace, Silica Crucible, Desiccator

Theory: Ash is inorganic matter left after igniting all the organic matter. Ash content of flour

gives indication of the milling efficiency. It is also useful in determining the flour grades like

low grade flour which has high amount of bran and will yield higher ash content.

Procedure:

1. Take 2gms of sample in a clean, dry and pre-weighed crucible.

2. Burn all the organic matter by placing the crucible on direct flame until the smoke stops

coming out from sample.

3. Put the crucible along with burned sample in a muffle furnace at 550°C for 6-8 hrs or

until the grayish white residue is obtained.

4. After this, take out crucible from muffle furnace and place it in a desiccator for about

20mins to cool.

5. Then take the weight of crucible along with ash.

6. Calculate percentage ash content as per formula.

Formula:

Weight of ash content x 100

Ash Content (%) = Weight of sample


Weight of empty Crucible: W1 (g)

Weight of Crucible + Sample: W2 (g)

Weight of Crucible + Ash: W3 (g)

(W3 – W1) x 100

Ash Content (%) = (W2 – W1)


Experiment # 3

Aim: Determination of gluten content in a given sample of wheat flour.

Requirements: Weighing Balance, Spatula, Stirrer, Beaker, Hot Air Oven

Theory: Gluten is water insoluble portion of wheat flour i.e. obtained after washing away the

starch and bran from the dough under running water and remaining elastic material in dough is

gluten.

Gluten is main portion present in wheat flour and made of gliadin and glutenin. They

absorb water during kneading of dough and result in cohesive and elastic gluten development.

During fermentation of dough in bread manufacturing, the gluten forms 3-D structure which

retains carbon dioxide and causes bread to swell.

For various wheat flour, amount of gluten can be given as:

Ø Whole wheat flour (6%)

Ø White wheat flour (6.6%)

Ø Semolina (12.5%)

Strength of wheat flour depends upon physical qualities of wheat grain. The flour obtained

from strong and hard wheat contains 11-13% gluten and hence preferred for bread

manufacturing. Soft wheat flour contains low gluten content i.e. 7-8% and is suitable for

preparation of biscuits and most of other products where fermentation is not required.

Gluten when dried and milled to powder and added to ordinary flour, it improves dough

ability to rise and increase the bread structure stability. Gluten is a special type protein

commonly found in wheat, barley, rye. Grains which do not have gluten are corn, millet, oat,

sunflower seeds.

Procedure:

1. Sieve the wheat flour and weigh 25gms of it.

2. Add sufficient amount of water slowly in flour and knead it to form stiff and smooth

dough i.e. dough that regains its shape when pressed gently with fingers.

3. Immerse the dough in water in a beaker for 30 minutes.

4. Take out dough from water, squeeze with fingers and gently press under stream of

running water until all the starch is washed out.

Perform the test to check whether the dough is free from starch or not as given in note

below.

5. Remove the loose water from the elastic material i.e. gluten and note down the weigh of

wet gluten.

6. Stretch the gluten in the form of thin layer and place it in a clean and dry pre-weighed

Petri plate.

7. Allow it to dry in a hot air oven at 130°C for 2-3hrs.

8. Take out the Petri plate along with dry gluten from oven and cool it in a desiccator for

15min.

9. Take the weight of dry gluten.

10. Calculate the percentage of wet gluten and dry gluten as per formula.

Formula:

Weight of wet gluten x 100

Wet Gluten (%) = Weight of sample


Weight of dry gluten x 100

Dry Gluten (%) = Weight of sample


Weight of wheat flour: W1 (g)


Weight of Petri plate + wet gluten: W3 (g)

Weight of Petri plate + dry gluten: W4 (g)

(W3 – W2) x 100

Wet Gluten (%) = W1

(W4 – W2) x 100

Dry Gluten (%) = W1

Note: Tests to check whether the dough is free from starch or not

a. Wash water test: Add a drop of water from the dough in a Petri plate containing clean

water. Absence of any milky appearance in water indicates that gluten is starch free.

b. Iodine solution test: Add a drop of water from the dough in Petri plate containing iodine

solution. If the iodine solution does not change the color, it means it is free from starch.


Experiment # 4

Aim: Determination of acidity or free fatty acids (FFA) in a given sample of wheat flour.

Requirements: Weighing Balance, Spatula, Conical Flask, Glass Stoppered Conical Flask,

Burette, Measuring Cylinder, Filter Paper, Funnel

Chemicals: Benzene, Ethanol, N/56 KOH, Phenolphthalein

Theory: Grains or their milled products undergo physical changes during storage. Acid

phosphates, amino acids, and free fatty acids of flour increases considerably due to enzymatic

hydrolysis of phytin, protein and fat respectively. Milled products deteriorate faster than their

parent grains. The fat acidity (FFA) increases rapidly whereas phosphate and amino acid

acidity increases only during advanced stages of deterioration. The amino acid and acid

phosphates are soluble in strong alcohol. The free fatty acids are soluble in fat solvents or in

strong alcohols. Benzene is used as a fat solvent to exclude acid phosphates and amino acids.

Principle: To the benzene extract, is added 0.04% phenolphthalein-ethanol solution in equal

volume so that the free fatty acids are transferred to alcoholic phase along with indicator to be

available for neutralization with N/56 KOH. The end point is pink or orange pink.

Fat acidity is defined as mg of potassium hydroxide required to neutralize free fatty

acids present in 100gm of sample.

Procedure:

1. Take exactly 20gms of powdered sample in 100ml glass stoppered conical flask.

2. Add 50ml of benzene and shake the flask for few seconds.

3. Loose the stopper to release benzene vapor pressure and replace it immediately.

4. Shake the flask for 45min manually or 30min by mechanical shaker.

5. Filter benzene extract through a coarse filter paper.

6. Take exactly 25ml of filtrate in 250ml conical flask.

7. Add 25ml alcoholic phenolphthalein (0.04%) solution.

8. Titrate against N/56 KOH.

9. Repeat for blank titration by taking 25ml benzene and 25ml alcoholic phenolphthalein

(0.04%) solution.

10. Calculate percentage free fatty acids as per formula.

Formula:

(A-B) x Normality of KOH x Eq. wt. of oleic acid x 100

FFA (%) = Weight of sample x 1000

(in terms of oleic acid)

Where,

A = Sample Titre

B = Blank Titre

Eq. Wt. of oleic acid = 282


Experiment # 5

Aim: Preparation of cake (eggless)

Requirements: Maida, Sugar, Condensed Milk, Milk, Baking Powder, Cocoa Powder, Oven

Theory: There are two types of cake:

1. Shortened cake: It contains fat as essential ingredient and is leavened chiefly with

baking powder. These cakes include white, yellow and chocolate cakes and pound cakes.

2. Unshortened cake: It does not contain fat as a basic ingredient. These cakes are

leavened by air or steam e.g. angel food cake.

Cake is made from flour, sugar, egg, milk, baking powder, and butter. The leavening

agent i.e. baking powder and eggs have important function in baking of cakes. They contribute

to the structure of cakes. Sugar affects flavor and structure of cakes. Butter is the most

common shortening used. Fat serves the important function of entrapping air during the

creaming process. Thereby leavening the batter and increasing the volume of baked cake.

Many flavors are used in small quantity in cake preparation. These ingredients have no other

effect on cakes other than imparting flavor. Other ingredients added for flavor are chocolate,

vanilla, pine apple etc.

Procedure:

1. Mix the liquid materials i.e. condensed milk, butter, and milk separately to a uniform

consistency.

2. Mix dry material i.e. maida, sugar, baking powder, and cocoa powder separately.

3. Mix all the contents uniformly to a batter using a beater.

4. Add crushed chocolate pieces into a batter.

5. Grease the tray and pour batter into it.

6. Bake it at 190 - 200°C for about 45mins or until it turns into slightly brown in color.

7. After recommended time, put needle in cake and check whether any material is sticking

to it or not.

8. If needle comes out without any material, then it means the cake is ready to eat.

9. It is also considered as end point in cake making.

Recipe: Maida – 250gms, Condensed milk – 200gms, Butter – 50gms, Baking powder – 2tsp,

Sugar– 125gms, Milk – 1cup, Cocoa powder – 2tbs

Flow Chart:

Collect Ingredients

Mix all liquid material (butter,

condensed milk, milk)

Mix all dry material (maida, sugar,

baking powder, cocoa powder)

Mixing together

Add crushed chocolate pieces

Pour batter into a greased tray

Bake in oven at 190 - 200°C for 45mins

Check with needle by inserting in cake, if it comes out clean then it means

cake is ready


Experiment # 6

Aim: Preparation of biscuits

Requirements: Maida, powdered Sugar, Milk, Butter/Ghee, Salt, Sodium Bicarbonate,

Ammonium Bicarbonate, Oven

Theory: Biscuit is a small quick bread usually made from flour, salt, butter or vegetable

shortening and with baking powder as a leavening agent. Quick breads are defined as any

bread i.e. not leavened by yeast. They are termed quick because they can be baked quickly than

having to wait for the action of yeast to leaven the bread. Biscuits differ from other baked

cereal products such as breads and cakes by having low moisture content. Bread has 35-45%

moisture, cakes have 15-30% moisture, and biscuits have 1-5% moisture. This low moisture

content ensures that biscuits are generally free from microbiological spoilage and have a long

shelf life, if they are protected from absorbing moisture from damp surroundings or

atmosphere.

Procedure:

1. All the solid ingredients like flour, salt, sugar, sodium bicarbonate, and ammonium

bicarbonate are mixed and are made into a paste by adding melted butter or ghee and then

kneaded to dough by adding milk slowly.

2. Dough formed is kneaded for 15-20mins to make it uniform.

3. Roll the dough into desired thickness (1/2 inch) and cut into pieces of desirable shape and

size.

4. Transfer the pieces into already greased baking tray and bake in pre-heated oven at 160°C

for 20mins.

5. After baking, take out tray from oven and allow to cool it.

6. After cooling, biscuits are packed and stored in cool and dry place.

Recipe: Maida – 250gms, Butter/Ghee – 50gms, Sugar – 75gms, Milk – 60ml, Salt - 2.5gms,

Sodium Bicarbonate – 1.5gms, Ammonium Bicarbonate – 1.2gms, Vanilla Essence –

few drops

Flow Chart:

Mix all dry materials

(flour, salt, sugar, sodium Bicarbonate, ammonium Bicarbonate )

Make a paste by adding butter/ghee

Make dough by adding milk slowly

Knead dough for 15-20mins and roll into desired thickness

Cut into pieces of desired size and shape and transfer into greased tray

Bake in pre heated oven at 160°C for 20mins

Take out tray and cool biscuits

Pack and store biscuits in cool and dry place


Experiment # 7

Aim: Study of parboiling of paddy

Requirements: Heating medium, Paddy, Oven

Theory: Parboiling is cooking of paddy i.e. hydrothermal treatment given to paddy followed

by drying. The process of parboiling comprises of three steps:

a. Soaking: The process of absorption of water by paddy is called soaking or steeping.

The absorption of water is a difficult process and will continue until equilibrium is obtained.

Soaking of paddy is done to provide starch with quantity of water, sufficient for gelatinization.

Soaking time is reduced by applying vacuum or soaking under pressure in hot water.

b. Steaming: Steaming of soaked paddy is done to gelatinize starch. During it, the granular

texture endosperm becomes pasty and any crack is sealed and endosperm becomes more

compact.

c. Drying: After parboiling, paddy contains high moisture. Soaking and steaming may

result in 35 – 40% moisture in paddy. It is dried quickly to about 14% moisture for safe storage

or for milling. The process of drying is carried out in two steps:

1. Paddy is dried to 18-20% moisture content, then heated and tempered for 4hrs.

2. It is again dried to 13-14% moisture content.

Advantages of Parboiling:

1. All cracks, chalkiness and other defects in rice which causes grain breakage during

milling are treated during parboiling.

2. Vitamins and other micro nutrients get fixed to the central parts of kernel during soaking

and steaming, so there is no removal of them during milling. Hence, milled parboiled rice

is nutritionally superior to milled raw rice.

3. Parboiled rice is harder and smoother than raw rice. However, it is not easily attacked by

insects. So milled product i.e. from parboiled rice is stored better than milled raw rice.

4. Oil in rice grain is pushed outward by heat during parboiling. Hence bran from parboiled

rice contains much more oil than from raw rice and is better raw material for oil

extraction.

Procedure:

1. Taka a vessel and fill it with nearly 3/4th

of boiling water. Add paddy and boil for half an

hour and drain the water.

2. The vessel is covered and left for half an hour.

3. The paddy is now parboiled and can be taken out.

4. It is dried to moisture content of 14%.


Experiment # 8

Aim: Study of Malting of Barley

Theory: Malt is germinated cereal grains that have been dried in a process known as "malting".

The grains are made to germinate by soaking in water, and are then halted from germinating further

by drying with hot air. Malting grains develops the enzymes required to modify the

grain's starches into sugars, including the monosaccharide glucose, the disaccharide maltose, the

trisaccharide maltotriose, and higher sugars called maltodextrines. It also develops other enzymes,

such as proteases, which break down the proteins in the grain into forms that can be used by yeast.

Malt also contains small amounts of other sugars, such as sucrose and fructose, which are not

products of starch modification but were already in the grain.

Malted grain is used to make beer, whisky, malted shakes, malt vinegar, flavored drinks

such as Horlicks, Ovaltine and Milo, and some baked goods, such as malt loaf, bagels and rich

tea biscuits. Malted grain that has been ground into a coarse meal is known as "sweet

meal". Various cereals are malted, though barley is the most common. A high-protein form of

malted barley is often a label-listed ingredient in blended flours typically used in the manufacture

of yeast breads and other baked goods.

Malting of Barley:

Malt is the product created through controlled germination and drying (or kilning) of

barley, and is primarily used for brewing beer. Malt production is a natural biological process

during which barley kernels are partially sprouted resulting in the modification of barley

endosperm.

This modification involves the breakdown of the cell wall components, the partial

breakdown of proteins, and the generation of the enzymes necessary for converting starch into

sugars during brewing. This process has been carried out for centuries, with malt originally

produced by hand and germinating barley turned using a shovel. Today, malting plants are highly

mechanized and automated, and operate 24 hours a day, 365 days a year.

The malting process consists of three stages: Steeping, Germination, Kilning

Steeping: Steeping is the first stage of the process, where barley is intermittently immersed in

water for about 36-48 hours to initiate germination. Biochemical reactions begin to take place in

the steeping stage, as enzymes are released and simple sugars supply energy to the growing

embryo. Barley moisture content reaches 42-45% after this process is completed and the

germination stage begins.

Germination: During the Germination Stage, the steeped barley continues to grow and

biochemical reaction occurs at a vigorous rate, as enzymes are produced which break down

proteins and other cell wall components. The steeped barley is held in tanks about 5 feet deep for

about 3.5 to 4.5 days, with air circulated through the germinating barley that is turned every 8 to 10

hours to ensure even germination. Moisture is maintained at about 44 to 47% moisture at

temperatures of 57 to 70ºF. The grain at this point is called "green malt". The green malt is

then kiln-dried to the desired color and specification. Malts range in color from very pale through

crystal and amber to chocolate or black malts.

Kilning: The Kilning Stage, the final stage of the malting process, occurs when heated air is

circulated through the product to end germination and the associated biochemical reactions.

Kilning also develops malt flavor and color, and dries the malt to preserve its quality. The malt, at

approximately 4% moisture is very stable and can be stored for several months. The sprouted

barley is kiln-dried by spreading it on a perforated wooden floor. Smoke, coming from

an oasting fireplace (via smoke channels) is then used to heat the wooden floor and the sprouted

grains. The temperature is usually around 55°C (131°F).

The finished malt is then usually shipped to a brewery, where the brewer crushes the malt

and adds water to it. By doing this, biochemical reactions are allowed to continue to take place and

starches and protein in the malt are further broken down. A sugar mixture, Wort, rich in maltose

and amino acids is created from the malt and is easily converted to ethanol by brewer’s yeasts.


Experiment # 9

Aim: Study of extraction of oil from rice bran

Theory: By weigh, rice bran has 17% oil content. After the refining process, the refined rice

bran oil weighs only 12% of the rice bran raw material. Different steps involved are as follow:

1. Extraction Process: The extracting process starts with raw material preparation. Rice

bran is first screened. It is then heated by steam at temperature higher than 100°C to stop lipase

hydrolysis in rice bran prior to extraction. Advance extracting technology and techniques were

developed with technical assistance from German and Belgian engineers in order to come up

with crude rice bran oil that is high in vitamin E and oryzanol. The crude rice bran oil is

forwarded to the refining process for purifying and packing.

2. Production: Rice bran is the brown layer of brown rice. It is the most nutritious part of

rice. Rice bran is rich in vitamin E and oryzanol, which are naturally present substances that

help to reduce blood cholesterol and fight against free radicals. Rice bran that is used for oil

extraction has to be freshly milled within no more than 24hrs to maintain the vitamins and

nutrition. Besides, since 20% of rice bran is germ, rice bran oil is rich in nutritionally natural

substances. Thus, in Japan, it is known as “heart oil”.

3. Refining Process: The advanced refinery technologies from Germany and Belgium

have been used at the refining process. Every production process is closely monitored resulting

in high oryzanol rice bran oil that is suitable for healthy cooking as well as cosmetics and spa

products. In order to obtain high quality refined rice bran oil, the refining process begins by

reducing excess free fatty acids and then decreasing the color with activated clay. After

decreasing color, the oil is forwarded to crystallization process before filtering the wax through

a filter press machine. The next process is to remove odor by using high pressure steam

deodorizer at 230-240°C. The heating medium used in this process is high pressure steam. No

thermal oil or PCB (Polychlorinated Biphenyl) involved in the production process at all. The

result is high quality and safe rice bran oil.

Rice Bran Oil Extracting Process


Rice Bran Refining Process

Crude Rice Bran Oil

NaOH

Degumming and Neutralization

Activated Clay

Bleaching

Winterization

Crude Rice Wax Filtration

Deodrization

Refined Rice Bran Oil

Rice Bran Air Separator Broken Rice

Steam Cooking & Drying

Solvent Extraction

Distillation

Crude Rice Bran Oil

Animal Feed

Desolventizing

Deoiled Bran

Animal Feed

Condensor

Solvent Storage

Solvent


FST – 404 (Processing of cereals & legumes)

List of Practical:

1. Determination of moisture content in a given sample of wheat flour

2. Determination of ash content in a given sample of wheat flour

3. Determination of gluten content in a given sample of wheat flour

4. Determination of acidity or free fatty acids (FFA) in a given sample of wheat

flour

5. Preparation of cake (eggless)

6. Preparation of cake biscuits

7. Study of parboiling of paddy

8. Study of Malting of Barley

9. Study of extraction of oil from rice bran