This is my investigatory project of class 12th chemistry. If you want to take help from this just download it guyz

1. Submitted by:
Dheeraj Singh
Class:XIth‘A
Roll No.:18
Under the Guidence of:
Mr.Sudhir Maingi
PGT(Chemistry)
Department of Chemistry
Kendriya Vidyalaya No. 1, Pathankot
Punjab

2. This is to certify that RAHUL KUSHWAHA, a student
of class XII-A has successfully completed the project
entitled “Quantity of casein in milk”under the
guidance of Mr. Sudhir Maingi during the year 2015-
16.The project is found worthy of acceptance as final
project for the subject Chemistry of class 12th. He has
prepared the project under my guidance.
(Signature of external examiner) (Mr. Sudhir Maingi)
PGT (Chem)
(Department of Chemistry)

3. Every organized report requires a lot of hard work and seeks a lot of
helping hands. Up to the completion of this project report, I was not so far
from this strategy or rule. Apart from the efforts of an individual, the
success of any project depends largely on the encouragement and
guidelines of many others. I take this opportunity to express my gratitude
to the people who have been instrumental in the successful completion of
this project.
First of all, I would like to show my greatest appreciation to our respected
teacher Mr. Sudhir Maingi for his proper guidance and moderation during
my class. I feel motivated and encouraged every time I attend their
lectures. Without their encouragement and guidance, this project would
not have materialized. Then I would like to give thanks to our respected
principal Mr. J.D Guru. I would like to thank him for his tremendous
support and help.
Plus, I would also like to thank to my dear friends and my dear parents for
their continuous support and help on the completion of my project work.
The guidance and support received from all the members who contributed
and who are contributing to this project, was vital for the success of the
project.
At last, I would like to remember and thank every individual who helped
me to complete my project report successfully.

4. INDEX
1. AIM OF PROJECT
2. INTRODUCTION
3. THEORY
4. APPARATUS REQUIRED
5. PROCEDURE FOLLOWED
6. OBSERVATION
7. CONCLUSION
8. BIBLIOGRAPHY

5. AIM OF THE
EXPERIMENT
 To study the quantity of casein
present in different samples of milk

6. INTRODUCTION:
Milk is a complete diet as it contains in its Minerals, Vitamins,
Proteins, Carbohydrates, Fats and Water. Average
Composition of milk from different sources are given below:
Source
of Milk
Water
(%)
Mineral
(%)
Protein
(%)
Fats
(%)
Carbohydrates
(%)
Cow 87.1 0.7 3.4 3.9 4.9
Goat 87.0 0.7 3.3 4.2 4.8
Sheep 82.6 0.9 5.5 6.5 4.5
Casein is a major protein constituent in milk and is a mixed
phosphor-protein. Casein has isoelectric pH of about 4.7 and can be
easily separated around this isoelectric pH. It readily dissolves in dilute
acids and alkalis.
Casein is present in milk as calcium caseinate in the form of micelles.
These micelles have negative charge and on adding acid to milk the
negative charges are neutralized.

8. THEORY:
Natural milk is an opaque white fluid Secreted
by the mammary glands of Female mammal.
The main constituent of natural milk are
Protein, Carbohydrate, Minerals, Vitamins, Fats
and Water and is a complete balanced diet.
Fresh milk is sweetish in taste. However, when it
is kept for long time at a temperature of 5
degree it become sour in taste because of
bacteria present in air. These bacteria convert
lactose of milk into lactic acid which is sour in
taste.
In acidic condition casein of milk starts
separating out as a precipitate. When the acidity
in milk is sufficient and temperature is around
36 degree, it forms semi-solid mass, called curd.

9. APPARATUS REQUIRED:
 Beakers (250 ml)
 Filter-Paper
 Glass Rod
 Weight box
 Filtration Flask
 Buchner funnel
 Test Tubes
 Porcelain Dish
 Different samples of Milk
 1% acetic acid solution
 Ammonium Sulphate
solution

10. PROCEDURE:
1. A Clean dry beaker has been taken, followed by
putting 20 ml of cow’s milk into it and adding 20
ml of saturated ammonium sulphate solution
slowly and with stirring. Fat along with Casein was
precipitated out.
2.The solution was filtered and transferred the
precipitates in another beaker. Added about 30 ml
of water to the precipitate. Only Casein dissolves in
water forming milky solution leaving fat
undissolved.
3. The milky solution was heated to about 40 degree
Celsius and add 1% of acetic acid solution drop-
wise, when Casein got precipitated.
4.Filtered the precipitate, washed with water and the
precipitate was allowed to dry.
5.Weighed the dry solid mass in a previously weighed
watch glass.
6. The experiment was repeated with other samples of
milk.

11. OBSERVATION:
Volume of the milk taken in each case = 20 ml
Name of milk: Percentage of Casein
Cow Milk 2.5-3.6
Goat Milk 2.5-3.3
Sheep Milk 4.3-4.6

12. Conclusion:
Different samples of milk contains
the different percentage of casein.

13. BIBLIOGRAPHY:
oHelp From Internet
oInformation from Library

14. oHelp From Teachers