INTRODUCTION
Milk is a multinutrient fluid and it is the primary source of nutrition for human. It consists of 80 % of proteins. The protein in the milk is classified into casein and protein. Milk protein consists of 80% of casein and 20% of protein. The function of casein is to provide energy to human body. The name of casein is related to the family of phosphoproteins. These protein are commonly found in the mammalian milk.
Casein is the main protein constituent of milk. It constitutes about 80% of the tot protein in cow’s milk and about 3% of its weight. It group of protein precipitated when the milk is slightly acidified. It dissolves slightly in water, extensively in alkalis or strong acids. Casein is a complete protein meaning that it contain all of the essential amino acids, which the body can not manufacture on its own. When dried, it is a white, amorphous powder without taste and odour. It is a mixed phosphoprotein and occurs in milk as calcium salt in the form of micelle. The micelle has a negative charge. When an acid is added to the milk, the negative charge are neutralized.
Calcium caseinate + Acetic acid gives Casein + Calcium acetate
The quality, quantity and fat content from the various milk samples differ with the type of particular mammals and their fodder. The composition of milk varies with according to the animals from which it comes, providing the correct growth rate and development for the young of that species.
Casein in a slow digesting protein and it was suspended 8n the milk in a complex called micelle. The micelles are spherical and are 0.04 to 0.03 m in diameter. The primary function of protein in living cell is ti promote growth and maintenance. The nitrogen content of milk is distributed among casein 76%, when protein and non- protein nitrogen is 6% . The structure of protein consist of a polypeptide chain of amino acids joined together by perude minister. Around the world, there are more than six villian consider of milk and milk products. Over 750 million people live in dairy farming households. It is used in points for fast drying water double medium. Casein based house are formulated fo. The picture of casein, water, hydrated like and podiyum hydroxide.
The composition of milk avarude with according to the animals from which it comes, providing the correct dosth rate and development for the young.
This study deals with the precipitation of casein from the various milk samples such as cow, goat , human and market milk. The technique of precipitation of casein is used to predict the protein content in the milk samples.
OBJECTIVES
1. To determine the amount of casein present in Cow milk.
2. To determine the amount of casein present in Goat milk.
3. To determine the amount of casein present in Human milk.
4. To determine the amount od casein present in market milk.
5. Compare the amount of casein present in different samples of milk.
PROCEDURE
Apparatus and Chemicals
. Beakers
. Funnel
. Chemical balance
.Test tubes
. Burner
. Different samples of milk.
Acetic acid solution
. Ammonium sulphate solution
1. Take a clean dry beaker, put into it 20cc of cow’s milk and add 20 ml of ammonium sulphate solution slowly and with stirring. Fat along with casein will precipitate out.
2. Filter the solution and transfer the precipitate in another beaker.
3. Add about 30 ml of water to the precipitate.
4. Only casein dissolves in water farming milky solution leaving fat undissolved.
5. Heat the milky solution to about 40c and add acetic acid solutions drop., When casein gets precipitated dry .
6. Filter the precipitate wash with water and let the precipitate dry.
7. Filter the precipitate wash with water and let the precipitation dry.
8. Repeat the experiment with other samples.
DATA COLLECTION
For this study, data collection was done by using primary sources like experimental method. This experimental method various apparatus and chemical substances are used to determine the amount of casein present in different samples of milk like, cow, goat , human and market milk.
Chemical substance like ammonium sulphate and acetic acid are used in experimental method.
ANALYSIS AND INTERPRETATION
From this study, the yield od casein precipitated from the various milk samples of cow, goat , human and market milk contains 6.2 gm ,5 gm ,4.1 gm and 3.5 gm respectively. This show that the casein precipitated from the cow milk contain more amount of casein protein than the goat and human milk samples. The lower amount of casein in the market milk is may be due to the more fat content in it.
Pure casein is an amorphous white solid without tast or odour. Commercial casein is slightly yellow, with a pleasant odour. Dry casein keeps well if protected from insects and rodents, damp casein is quickly attacked by molds and bacteria and acquires a disagreeable odour. The specific gravity is 1.25 to 1.31 . Casein is a mixture of phosphoprotein of differing molecular weight.
Casein is a lyophilized colloid akin to albumin and gelatin. It is isoelectric at pH 4.6 where it’s solubility in water is but 0.01 percent. It is amphoteric, below pH 4.6 casein forms moderately soluble salts such as casein chloride, above pH 4.6 casein forms salts with bases.
Sodium caseinate and other alkali salts are soluble without limit, while calcium caseinate, other alkaline earth salts and heavy metal salts are nearly insoluble. Formaldehyde forms an insoluble compound with casein . Paracasein is less lyophilic but otherwise identical with casein . Casein is insoluble in most organic solvents
Casein is usually made from skim milk, by one of three methods,
1. Naturally soured casein curdles when enough lactic acid develops from fermentation of milk sugar by the ever present bacterium streptococcus lactis.2
2. Acid casein is precipitated by adding dilute hydrochloric acid or sulphuric acid.
3. For rennet casein ,warm skim milk is set with rennet extract until the calcium paracaseinate clots, after which the clot is cut into small pieces to allow the whey to drain.
In all three methods the whey is drawn off , the curd washed with water, drained or pressed, dried in warm air, ground and packed for sale. Rennet casein retains much of the calcium phosphate from the milk.
FINDINGS AND CONCLUSION
This study clearly indicated that the amount of casein precipitated from the cow milk samples. The quantitative analysis of casein precipitated from the various milk samples provide the ample scope to the cottage cheese manufacturers.
According bro research finding, cow milk contains the largest amount of casein protein. Thus, the cow milk is suitable for the best muscle growth and basic body building achievement. It was found that goat milk contain the small amount of casein protein . Although the mineral content of goat milk and cow milk is generally similar, goat milk contain more calcium, potassium , iron , magnesium and sodium. All milk has lots of casein but there are different types of casein and for someone who has casein sensitivity, goat milk may provide an alternative to which they do not react.
My findings 