chemistry proj1 new

8/2/2019 Chemistry Proj1 New

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ANALYSISOF

MILK

Submitted By : R BHARATH KUMARClass : XII-BRoll No. :


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ACKNOWLEDGEMENT

It is a great pleasure to express my sincere

thanks and gratitude to my respected

Chemistry Teacher Mrs. CHARU ARORA, who

had extended me full co-operation and guided

me in bringing out this Project successfully. I

am also highly obliged to Chemistry Laboratory

assistant Mr.A SHARMA who provided me the

necessary materials and also gave me useful

tips.

R.BHARATH KUMARXII B


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CERTIFICATE

This is to certify that R.BHARATH KUMAR,

Class 12TH B Of Ramjas School has successfully

completed his project and has given a

satisfactory account of the experiment on my

supervision.

(Mrs.Charu Arora)Chemistry Teacher


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INTRODUCTION

Milk is one of the most important and essential

requirements of our daily needs. It fulfills thebasics nutritional requirement as it containsproteins, carbohydrates, calcium, phosphorousetc.

Chemically carbohydrates are polyhydroxy ketoneand aldehydes derivates, whereas proteins are

complex nitrogenous organic substances. All theseare required for normal growth and developmentof the body, especially for growing children andlactating mothers.

Now-a-days, people having an extra lure formoney, have started making synthetic milk

thereby decreasing its quality and posing threatto society. This milk is being sold at a cheaperrate to attract people. A whole generation ofinfants in northern India is at risk of developingdiseases due to drinking poisonous milk, i.e.,SYNTHETIC MILK being pumped into market byunspurious Traders.

SYNTHETIC MILK has low nutrional value. Theproject herby includes simple methods to detect'ADULTERATION IN MILK'.


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AIM OF THE PROJECT

To Study Various components and Adulterants

present in different samples of milk available in

the market.


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MilkWhere does milk come from?

Milk is a complex biological fluid, the composition and physicalcharacteristics of which vary from species to species, reflecting thedietary needs of the young mammal. The major constituent of milk iswater, but depending on the species, milk contains varying quantities oflipids, proteins and carbohydrates that are synthesised within themammary gland. Also present are smaller quantities of minerals andother fat-soluble and water/soluble components derived directly fromblood plasma, specific blood proteins and intermediates of mammarysynthesis.

In many parts of the world the cow is of overwhelming importance in

milk production, and in some countries milk from species other than thecow is not legally defined as milk.

Species Water Fat Casein Whey

protein

Lactose Ash

Cow 87.3 4.4 2.8 0.6 4.6 0.7

Buffalo 82.2 7.8 3.2 0.6 4.9 0.8

Composition of milk (g/100g) of different species.

What is in milk?

Some of the essential minerals and vitamins such as iron and vitamin Dare, however, not present in sufficient amounts, or in optimumproportions, to fulfill the requirements for complete nutrition

Composition of raw milk.Quantities of the various main constituents of raw milk from cows canvary considerably; between cows of different breeds and betweenindividual cows of the same breed. Water is the principal constituent andit is the carrier of all other components. Cows' milk consists of about 87% water and 13 % dry substance that is suspended or dissolved in the


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water. Beside total solids, the term solids-non-fat (SNF) is used indiscussing milk composition.Fat .Fat weighs less than water and exists as small globules or droplets

dispersed in the milk serum. Because of its lower weight, fat rises upand floats on the surface of milk, causing a cream layer. The taste ofthis fat (butter) is creamy and somewhat sweet, and it has a light yellowcolor.Protein .Proteins are the most important nutrient in milk and an essential part ofour diet. They are present as a solution in milk, and the proteins weconsume are broken down into simpler compounds in the digestivesystem and the liver.

These compounds are then conveyed to the cells of the body, wherethey are used as construction material for building the body's ownprotein. Proteins are giant molecules built up of smaller units calledamino acids, and a protein molecule consists of one or more interlinkedchain(s) of amino acids.

Casein .The proteins in milk consist to 80 % of casein, which in turn is made upof a number of components that together form complex particles ormicelles.

Whey proteinProteins are built up completely differently and therefore also havetotally different characteristics. In general, whey proteins have very highnutritional values and they are widely used in the food industry. Wheyprotein is also called serum protein.Non-protein nitrogenous compounds (NPN)The presence of nitrogen is one of the main characteristics of proteins,but traces of non-protein nitrogenous products are also found in milk.

Percentage of different compounds in milk.


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Minerals and saltMilk contains a number of minerals, with a total concentration of < 1 %.The most important salts are calcium, sodium, potassium andmagnesium. These occur as phosphates, chlorides, citrates andcaseinates.

Vitamins .Vitamins give milk its taste and are essential for normal life processes.Milk contains many vitamins and among the best known are A, B1, B2,C and D. Vitamins A and D are soluble in fat, or fat solvents, while theothers are soluble in water.Enzymes .Enzymes (catalysts) are a group of proteins produced by livingorganisms. The action of enzymes is specific: each type of enzyme

catalyses only one type of reaction. Two factors that strongly influenceenzymatic action, are temperature and pH. Several of the enzymes inmilk are utilised for quality testing and control.

LIPASE splits fat into glycerol and free fatty acids. When milk has beendamaged, lipase causes differences in taste.

PEROXIDASE is activated if the milk is heated to 80 C for a fewseconds. This can be used to prove the presence or absence ofperoxidase in milk and thereby check whether or not a pasteurisation

temperature above 80 C has been reached.

CATALASE splits hydrogen peroxide into water and free oxygen. Milkfrom diseased udders has a high catalase content, while fresh milk froma healthy udder contains only an insignificant amount.

PHOSPHATASE is able to split certain phosphoric-acid esters intophosphoric acid and alcohol. Phosphatase is destroyed by ordinarypasteurisation (72 C for 15 seconds). The phosphatase test can beused to determine whether the pasteurisation temperature has been

attained.


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DETECTION OF VARIOUS

CONSTITUENTS OF MILK

CARBOHYDRAYES

PROTIENS

PHOSPHATE

WATER

MILK SUGAR

VARIOUS SAMPLES OFMILK TAKEN

SAMPLE A: MOTHER DIARY-Full Cream MILK

SAMPLE B: PARAS MILK

SAMPLE C: ORDINARY OPEN MILK


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EXPERIMENT 1

AIM : To study the presence of carbohydrates in given samples.

FIRST TEST : Take 1ml of milk. Add 0.5 ml of Molish Reagent and add a fewdrops of H2SO4 to it.

RESULT

SAMPLE A : Reddish ring formed

SAMPLE B : Reddish ring formed

SAMPLE C : Reddish ring formed

CONCLUSION : All 3 samples contain carbohydrates

SOCOND TEST : Take 1ml of milk. Add 0.5 ml ofHCL. Add Fehlings Solution A & B

to it. Heat the solution.RESULT

SAMPLE A : Red ppt. is formed

SAMPLE B : Red ppt. is formed

SAMPLE C : Red ppt. is formed

CONCLUSION : All 3 samples contain carbohydrates


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EXPERIMENT 2

AIM : To study the presence of proteins

present in given samples.FIRST TEST : Take 1ml of milk. Add 0.5 ml of

CuSO4 and NaOH to it.

RESULT

SAMPLE A : Violet Colour formed

SAMPLE B : Violet Colour formed

SAMPLE C : Violet Colour formed

CONCLUSION : All 3 samples contain proteins.

SOCOND TEST : Take 1ml of milk. Add MillionsReagent. Heat for some time

RESULT

SAMPLE A : Red Colour formed

SAMPLE B : Red Colour formed

SAMPLE C : Red Colour formed

CONCLUSION : All 3 samples contain proteins.


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EXPERIMENT 3

AIM : To test the presence of phosphatepresent in the given samples.

PROCEDURE : Take 5ml of milk. Add 2 ml of Conc.HNO3 and AmmoniumMolybdate on slight heating.

Observations

SAMPLE A : Yellow ppt. formed

SAMPLE B : Yellow ppt. formed

SAMPLE C : Yellow ppt. formed

Inference : All 3 samples contain Phosphate.


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EXPERIMENT-4

AIM : To study the presence of water in

the given samples.

PROCEDURE : Take 5ml of Diphenylamine

solution and pour the milksamples along the sides of the test

tube.

Observations

SAMPLE A : Blue ring formed

SAMPLE B : Blue ring formed

SAMPLE C : Blue ring formed

Inference : All 3 samples contain water.


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DETECTION OF VARIOUS

ADULTRANTS IN MILK

UREA

CAUSTIC SODA

BACTERIA


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EXPERIMENT-5

AIM : To detect the presence of urea in

the given samples of milk.

PROCEDURE : Prepare dimethyl aminobenzaldehyde solution in Conc.Hcl.Add a few drops of milk in the test

tube along with the preparedsolution.

Observations

SAMPLE A : No ppt. formed

SAMPLE B : Pale Yellow ppt. formed

SAMPLE C : Yellow ppt. formed

Inference : Sample C contains maximum

amount of urea. Hence,

it is synthetic in nature.Sample A is the purestone followed by B.


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EXPERIMENT-6

AIM : To detect the presence of causticsoda in the given samples

of milk.

PROCEDURE : Take the sample of milk and add afew drops of

phenolphthalein to itObservations

SAMPLE A : No change is observed.

SAMPLE B : No change is observed.

SAMPLE C : Pink coloration.

Inference : Sample C contains caustic soda. Itfurther ensures that it issynthetic in nature.

Sample A & B are pureand free from caustic

soda.


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EXPERIMENT-7

AIM : To estimate the amount of

bacteria present in the givensamples of milk.

PROCEDURE : Take equal volumes of givensamples. Add 2ml ofmethylene blue to it.

Note the time taken byeach sample to reduce

the dye indicated by

conversion of blue colorto white. For pure milk itshould not be less than 5

hours.

Observations

SAMPLE A : 5 hrs. 30 minutes.

SAMPLE B : 5 hrs. 38 minutes.

SAMPLE C : 35 minutes.

Inference : Sample C is highly contaminated

with high level of bacteria. Sample A & B

are pasteurized.


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CONCLUSION OF THE PROJECT

SAMPLE A: MOTHER DIARY-Full Cream MILK

Mother diary milk contains all the nutrients and amount

of adulterants was negligible. Hence, it is good quality

milk. Urea, caustic soda and bacteria presence is null.

SAMPLE B: PARAS MILK

Paras milk was more or less equivalent to Sample A

except for the quantity of the nutrients which is little

high. The presence of urea, caustic soda and bacteria is

negligible, Hence it is also pure.

SAMPLE C: POLYPACK-ORDINARY OPEN MILK

Open milk is highly contaminated and contains large

amount of adulterants. It certainly is synthetic milk, as it

contains Urea, Caustic soda and bacteria.


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BIBLIOGRAPHY

1. Lab Manual in Chemistry

2. Internet

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