8/8/2019 UPTU Food Chemistry Qp

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B.TECH EFT-501

FIFTH SEMESTER EXAMINATION, 2009-10

Food ChemistryTime: 3 Hours Total Marks: 100

Note: (1) Attempt all questions.

(2) All questions carry equal marks.

Q 1 Attempt any FOUR parts of the following: 5x4=20

(a) Describe the correlation between water activity and growth of microorganism in foods.

(b) Explain the interaction mechanism of water with non-polar substances of foods.

(c)  Explain in brief hysteresis in moisture sorption isotherm.

(d) Differentiate between amylopectin and protopectin and indicate their sources.

(e) Explain the factors influencing the strength of food grade polysaccharides gels.

(f)  Discuss the browning reactions of food. Explain the merits and demerits of these

reactions.

Q2 Attempt any FOUR parts of the following: 5x4=20

(a) Discuss the factors affecting the consistency of commercial fats.

(b) Describe the general characteristics of auto-oxidation of lipids.

(c)  Describe the control measures for good manufacturing practice for fried foods.

(d) Differentiate between hydrolytic rancidity and oxidative rancidity.

(e) What do you understand by lypolysis of lipids. Explain the implications of lipolysis in

foods.

(f)  Comment on safety of heated and oxidized fat.

Q3 Attempt any TWO parts of the following: 10x2=20

(a) Define food proteins. Write names of amino acids of protein. Also indicate the aminoacids essential for human being and infants.

(b) What do you understand by denaturation of proteins. Explain its implications and name

the physical and chemical agents causing denaturation of proteins.

(c)  Describe the changes in the functional properties of proteins due to modification in its

conformation during processing of foods.

Q4 Attempt any TWO parts of the following: 10x2=20

(a)  What are general causes for loss of vitamins and minerals during processing and storage

of foods.

(b) Describe the structure of chlorophyll. Comments on the preservation of green colour in

processed foods.

(c)  Comment on development of process and reaction flavor volatile compounds.

Q5 Write a technical notes on any TWO of the following: 10x2=20

(a) Milk Protein

(b) Biochemical changes in muscle postmortem

(c)  Functional properties of egg

8/8/2019 UPTU Food Chemistry Qp

http://slidepdf.com/reader/full/uptu-food-chemistry-qp 2/2

B.TECH EFT-501

FIFTH SEMESTER EXAMINATION, 2009-10

Food ChemistryTime: 3 Hours Total Marks: 100

Note: (1) Attempt all questions.

(2) All questions carry equal marks.

Q 1 Attempt any FOUR parts of the following: 5x4=20

(a)  Define aw. Explain the effect of temperature on aw. Discuss correlation between aw and

stability of foods.

(b)  Explain the importance of hydrolysis reaction of carbohydrate in food industry.

(c)  Explain the correlation between water activity of foods and growth of microorganisms in

foods with suitable examples.

(d) Describe the structure function relationship of polysaccharides and their implications in

foods

(e) Describe the moisture sorption isotherms of foods. Explain hysteresis and its implication in

foods.

(f)  Discuss the merits and demerits of browning reactions in food processing.

Q2 Attempt any FOUR parts of the following: 5x4=20

(a)  Describe the good manufacturing practices for deep fat fried foods.

(b)  Explain the implications of lipolysis in foods.

(c)  Discuss the polymorphic behavior of commercial fats with suitable example.

(d)  Explain Solid fat Index (SFI).Discuss its relevance in functional properties of fats.

(e) Discuss the factors influencing the rate of lipid oxidation in foods.

(f)  How do you assess the quality of frying oils.

Q3 Attempt any TWO parts of the following: 10x2=20

(a)  Describe the processing-induced physical, chemical and nutritional changes in proteins.

(b) Describe the emulsifying and foaming properties of food proteins

(c)  What do you understand by protein quality? Describe the various ways to evaluate the

nutritive value of protein.

Q4 Attempt any TWO parts of the following: 10x2=20

(a)  Enlist water soluble and fat- soluble vitamins. Explain the chemical and physiological

characteristics of vitamin C. what are deficiency problems in human being.

(b)  What are natural color pigments occurring in plants?Describe and discuss the effect of 

heating / cooking, and pH on the color pigments.(c)  Explain the factors affecting the bioavailability of minerals in unmodified and processed

foods.

Q5 Write a technical notes on any TWO of the following: 10x2=20

(a) Muscle tissues & quality of meat

(b)  Casein micelle and milk salts

(c)  Egg inhibitors