amount of casein in different milk samples

D.A.V PUBLIC SCHOOL

Chemistry project

AMOUNT OF CASEIN IN DIFFERENT SAMPLES OF MILK

MANISHA LOHIA CLASS-XII-A

PREFACE CERTIFICATE This is to certify that Manisha Lohia, Roll no. studying in standard XII-A ,of D.A.V PUBLIC SCHOOL for the session 2015-16 has worked on the project of chemistry and completed the same satisfactorily during the academic year.

ACKNOWLEDGEMENT I wish to express my deep gratitude and sincere thanks to the Principle, Anju Puri, DAV Public School , VK for her encouragement and all the fascilities that she provided for this project work.I sincerely sappreciate this magnanimity by taking me into her fold for which i shall remain indebted to her. I extend my hearty thanks to Ms. Swastika Sharma, chemistry teacher who guided me to the successful completion of this project.I take this opportunity to express my deep sense of gratitude for his invaluable guidance, constant encouragement, sympathetic attitude, constructive comments, and immense motivation which has sustained my efforts at all stages of this project. I cant forget to offer my sincere thanks to my classmates who helped me to carry out this project work successfully and for their valuable advice and support which i received from them time to time.

INTRODUCTION ABSTRACT OF REPORT  Milk is the best and cheapest source of nutrition and an article of daily diet, easily accepted and used by all the age groups in rural as well as in urban areas.  . Although slightly varies in composition and properties, the milk of different species contain the same constituents in general. On average, milk is made up of 87.4% water and 12.6% milk solids (3.7% fat, 8.9% milk solids-not-fat).  The milk solids-not-fat contain protein (3.4%), lactose (4.8%), and minerals (0.7%). Milk fat often called “butter fat” is commercially, the most valuable constituent of milk.  It is also of great importance from the standpoint of the food value of the milk.

 The protein of milk is not a single compound but includes two major proteins and small quantities of others. Between them casein constitute about 80 % of the total and lacto albumin 18%. A third protein recognized as present in milk is lacto globulin. It is present in very small amounts, probably about 0.05 to 0.07 %.

CONTENTS  Aim  Requirements  Theory  Benefits of casein protein  Procedure  Observations  Conclusion  Bibliography

AIM To Study The Quantity Of Caesin Present In Different Samples Of Milk

REQUIREMENT           

Beakers (250ml) 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 

THEORY

Casein is a phosphoprotein which has phosphate groups attached tosome of the amino acids side chains. These are attached mainly to the hydroxyl groups of the serine and threonine moieties. Actually, casein is a mixture of at least three similar proteins, which differ primarily in molecular weight and amount of phosphorus they contain (number of phosphate groups). Casein exists in milk as the calcium salt, calcium caseinate. The pH of milk is about 6.6; therefore casein has a negative charge at this pH and is solubilized as a salt. If acid is added to milk, the negative charges on the outer surface of the micelle are neutralized (the phosphate

groups are protonated) and the neutral protein precipitates: Ca2+Caseinate + 2 HCl ─› Casein + CaCl2 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 Caseinate in the form of “micelles”.these micelles have negative charge and on adding acid to milk the negative charges are neutralised.

BENEFITS OF CESEIN PROTEIN 1. Casein is a Slow Digesting Protein Casein is a slow digesting protein. Casein clots in stomach, forming large globules of protein (1). This slows down the rate of the gastric emptying, meaning amino acids in casein enter the bloodstream at a sustained rate

b.Helps Promote Colon Health In a study performed out of Australia, researchers investigated the health benefits of various proteins and found that dairy proteins promote colon health better than meat and soy. This proves to be yet another reason why you should strongly consider adding casein protein to your daily intake.

2. Casein For Building Muscle , Strength and Recovery Protein has been shown in tons of scientific studies to increase protein synthesis and the development of lean muscle mass. During a workout in order to make progress muscle fibres must be torn and repaired. Through providing an extensive Branched chain amino acid profile, including leucine, iso leucine and valine, casein allows for the repair and recovery of muscle fibres which cannot only decrease muscle soreness, but also help you achieve your goals at a quicker rate.

3. Casein For Bones and Teeth

Studies have shown that casein consumption can help boost teeth enamel, helping to reduce acid erosion.

PROCEDURE 1. A clean dry beaker has been taken, followed by putting 20 ml of milk into it and adding 20 ml of saturated ammonium sulphate solution slowly and with stirring. Fat along with Casein was precipitate 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 40oC and add 1% 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.

WEIGHT OF S.NO.

SOURCE OF MILK

DRIED SOLID MASS ( mg per 20ml of milk)

1

Cow milk

20.10

2

Amul toned

19.99

3

Amul tetra

20.01

pack 4

Buffalo milk

OBSERVATIONS

22.1

CONCLUSION The BUFFALO milk has highest value of the dried solid mass i.e. the composition of Casein is highest in the sample of BUFFALO milk.

REFERENCES /BIBLIOGRAPHY  Wikipedia  Encyclopedia  Icbse.nic.in  Practical chemistry Book