LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION - FOOD CHEMISTRY & FOOD PROCESSING
SECOND SEMESTER – APRIL 2012
FP 2802 - CHEMISTRY OF DAIRY PRODUCTS
Date : 21-04-2012
Time : 9:00 - 12:00
Dept. No.
Max. : 100 Marks
Part A
Answer all the questions:
2x10 =20
1. Define milk and write the composition of cow’s milk.
2. What is density and specific gravity of milk?
3. What is mutarotation of lactose?
4. Draw the structure of α and β forms of lactose.
5. List any four treatments that change the milk salt equilibria.
6. Name the proteins present in milk.
7. ‘Infants digest human milk more efficiently than bovine milk’. Why?
8. Write any four functions of milk lipids.
9. Define Koestler’s number.
10. Calculate % total solids of milk if corrected lactometer reading is 32 and fat is 3.0 %.
Part B
Answer any eight questions:
8x5=40
11. Write short notes on the rheological property of milk fat and milk gels.
12. Briefly describe the acidity and freshness of milk.
13. Define Maillard’s reaction. Explain the reaction scheme.
14. i) Mention the methods used for lactose determination ii)Write in brief about lactose redox titration.
15. Write the amino acid composition of casein.
16. i) What are casein micelles?
ii) Draw the structure of casein micelles and write any six stability properties of the micelle
structure.
17. What are the factors that affect the fat content of milk?
18. Graphically represent and write in brief the correlation between concentration of i)sodium and
potassium in milk ii)sodium and chlorides in milk iii)Lactose and solube salts in milk.
19. Briefly describe the synthesis of fatty acids in milk fat.
20. How do you check adulteration of milk with water using a lactometer?
21. Write short notes on syneresis in cheese making and factors affecting it.
22. a) What is cultured or fermented milk product?
b) Diagrammatically represent buttermilk preparation and write the chemistry involved in this.
Part C
Answer any four questions:
4x 10=40
23. Mention the colligative properties of milk .
a) Write in detail about the factors affecting freezing point & determination of freezing point
in milk.
b) Explain in detail about the problems related to lactose crystallization in milk powder and whey
powder.
24. Explain the effect of i) heat on Vitamin A, Folate and Pyridoxine (B6).
ii) light on riboflavin and Vitamin D.
25. Write about the following. a) Heterogeneity in milk proteins.
b) Acid isoelectric precipitation of casein c) gel electrophoresis of proteins.
26. Give a detailed account about the factors that affect the composition of milk salts.
27. a) Define milk fat globular membrane.
b) Give a detailed account about the composition of milk fat globular membrane.
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