Hello everyone this is a chemistry project

1. ARMY PUBLIC SCHOOL
JHANSI
2022-2023
CHEMISTRY PROJECT
-TOPIC-
STUDY THE QUANTITY OF CASEIN PRESENT
IN DIFFERENT SAMPLES OF MILK
SUBMITTED BY: SUBMITTED TO:
NAME-Anuj Kumar Mr. Rajesh Trivedi
CLASS-XII A
ROLL NO.-06

2. CERTIFICATE
2022-2023
NAME-Anuj Kumar
Class-XII A
ROLL NO.-06
INSTITUTION-ARMY PUBLIC SCHOOL JHANSI
This is to certify that Anuj Kumar of class XII A has
successfully completed the project on the topic "STUDY
THE QUANTITY OF CASEIN PRESENT IN
DIFFERENT SAMPLES OF MILK". During the academic
year 2022-2023.
Examiner’s Signature Teacher in charge
Principal
Institution rubber stamp

3. ACKNOWLEDGEMENT
I wish to express my deep gratitude and
sincere thanks to Mr. Rajesh Trivedi for his
encouragement and for all the guidance
that he provided on this project work. I
take this opportunity to express my deep
sense of gratitude to my parents for their
invaluable guidance, constant
encouragement, constructive comments,
sympathetic attitude and immense
motivation which has sustained my efforts
at all stages of my life.

4. CONTENT
➢INTRODUCTION
➢OBJECTIVE OF THE PROJECT
➢MATERIAL REQUIRED
➢PROCEDURE
➢OBSERVATION
➢CONCLUSION
➢BIBLIOGRAPHY

5. INTRODUCTION
Milk is a white liquid produced by the mammary glands of
mammals. It is the primary source of nutrition for infant
mammals (including humans who breastfeed) before they are
able to digest other types of food. Early-lactation milk contains
colostrum, which carries the mother's antibodies to its young
and can reduce the risk of many diseases. It contains many
other nutrients including protein and lactose. As an agricultural
product, milk is extracted from non-human mammals during or
soon after pregnancy. Dairy farms produced about 730 million
tons of milk in 2011, from 260 million dairy cows. India is the
world's largest producer of milk, and is the leading exporter of
skimmed milk powder, yet it exports few other milk products.
The ever increasing rise in domestic demand for dairy products
and a large demand-supply gap could lead to India being a net
importer of dairy products in the future. The United States, India,
China and Brazil are the world's largest exporters of milk and
milk products. China and Russia were the world's largest
importers of milk and milk products until 2016 when both
countries became self-sufficient, contributing to a worldwide glut
of milk.
Model of Casein Micelle

6. The major milk protein casein is found only in milk and now here in the
world. The composition of casein is not constant and depends upon the
source of milk.
Average composition of milk from different sources is given below:
Source of
Milk
Water
(%)
Mineral
(%)
Protein
(%)
Fats
(%)
Carbohydrates
(%)
COW 87.1 0.7 3.4 3.9 4.9
HUMAN 87.4 0.2 1.4 4.0 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 alkalies. Casein is present in milk as calcium.
Casein ate in the form of micelles. These micelles have negative charge
and on adding acid to milk the negative charges are neutralized.
C𝑎2+
-Caseinate+2C𝐻3COOH(aq)→Casein+(C𝐻3COOH)𝟐Ca
Diagram showing the action of rennet on the Casein Micelle. The
enzyme in rennet cleaves the Casein releasing a large peptide. The
surface of the Micelle changes from being hydrophilic and negatively
charged to hydrophobic and neutral. As a consequence, the Micelle
aggregate to trap fat globules and microorganism in developing curd.

7. OBJECTIVE OF THE PROJECT
"To Study The Quantity Of Casein Present In
Different Samples Of Milk"
Casein Micelle

8. MATERIAL REQUIRED
➢ Beaker (250ml)
➢ Filtration Flasks
➢ Measuring Cylinder
➢ Glass Rod
➢ Spatula

9. ➢ China Dish
➢ Dropper
➢ Weight Machine
➢ Different Samples of Milk

10. ➢ Acetic Acid (10%)
➢ Saturated Ammonium Sulphate
➢ Burner
➢ Water (𝐻2𝑂)

11. ➢ Filter Paper

12. PROCEDURE
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 precipitate out.
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.
The milky solution was heated to about 40° C and adds 10% acetic acid
solution drop-wise, when casein got precipitated.
Filtered the precipitate, washed with water and the precipitate was
allowed to dry.
Weighed the dry solid mass in a previously weighed watch glass.
The experiment was repeated with other samples of milk.
Protein Chain with Peptide Bond
R=Amino Acid Group

13. OBSERVATION
Sample No. Source Content of
Proteins
% of Casein
1 Cow Milk 0.60 3.00
2 Goat Milk 0.65 3.25
3 Buffalo Milk 0.85 4.20
4 Amul Milk 0.75 3.88

14. CONCLUSION
Different samples of milk contain different
percentage of Casein.
Milk Protein: Casein
➢ Caseins are the primary protein in milk (80%)-other 20% is whey
➢ Exist as micelles whose biological function is to deliver large amounts
of calcium to the infant
➢ Why is it able to do that? High phosphate content
➢ Denaturation at pH 4.6
➢ Random, loose structure due to the amino acid composition (high
proline content)
➢ Heat alone will not denature casein (acid is needed, too)
➢ Curdles once hydrophobic residues are exposed

15. BIBLIOGRAPHY
1. XII class Chemistry NCERT Books
2. iCBSE.com
3. XII class Chemistry Practical Book
4. Photos from Google images
5. More Information from Wikipedia...
THE END!