Chemistry Project Report
Study of Quantity of Casein Present in
Various Samples of Milk
Student of XII-Science (Chemistry)
Submitted to :
Lecturer in Chemistry
Sr. Sec. School
(e) Result and discussion
This is certified that the chemistry project report entitled "A
project on the study of quantity of casein in different samples of milk"
submitted for partial fulfillment of XII Sc. Practical examination in the
subject of Chemistry embodies a record of original study carried out by student
under my Supervision.
This project in my opinion is completed and is suitable for presentation.
Lecturer in Chemistry.
Milk is a white liquid secreted by the mammary glands of female cows,
buffaloes etc. It is a food of exceptional inters probability. Milk is the most
nutritious food found in nature. That is why it is widely consumed both in its
natural forms and as diary product like butter, cheese etc.
Milk contains vitamins, proteins, carbohydrates and the major milk protein casein are found only in milk and nowhere else in nature. The Composition of
casein in milk is not constant. It depends upon the source of milk.
The protein, casein, existent, milk as the calcium salt, calcium casein etc. The
salt has a complex structure and form micelles. These micelles have negative
charges on the outer surface.
250-ml. beaker, filtrations flask, measuring cylinder, glass rod, spatula, china
dish, dropper, and weight bore, different samples of milk, 10% acetic acid.
- Measure 20-ml, of a milk sample with the help of measuring cylinder and
transfer into a clean 250ml. beaker.
- Make the volume of milk to about 35ml, by adding water and warm the
mixture to about 40 c.
- Add to the warm mixture drowse and with constant stirring 10% acetic
acid unit the precipitation is completed.
- Stir the mixture for another 10 minutes or till the precipitated casein
forms a large amorphous mass.
- Filter the casein precipitate.
- Wash thoroughly with water, dry foils between folds of filter paper and
then in air for 1-2 days weight the dry solid so obtained.
- Similarly, determine the amount of casein in other samples of milk.
Volume of Milk Taken in each case = 20ml.
||Quality of Milk
||Weight of casein
||percentage of casein
Therefore if an acid is added to milk the negative charge are neutralized and
the neutral protein precipitated out.
Ca+2 (casemated) +2 CH3 COOH (aq)
Casein + (CH3 COO)2 Ca
Results and Discussion :
Different samples of milk contain different percent of casein and the casein
contents in maul brand are appreciable. At present amul is the best brand of milk
available in the market.
- Laboratory manual in chemistry Class XII by B.Bhushan
- Advanced organic practical chemistry for P.G. Students & by O.P.
- Internet Source : www.google.com