JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY
University Examinations 2016/2017
YEAR IV EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN ANIMAL HEALTH, PRODUCTION AND PROCESSING
AFS 2310: FUNDAMENTALS OF DIARY SCIENCE
DATE: DEC, 2016 TIME: 2 HOURS
INSTRUCTIONS: Answer ALL Questions in Section A and any TWO question from Section B.
Section A – 30 Marks
a) Write short notes on the following as they relate to the composition of milk:
i. Stage of lactation [3 marks]
ii. Feeding [4 marks]
iii. Disease [3 marks]
b) i. Some ingenious farmers add water to milk to increase its volume but small processing plants are unable to detect it. Explain why. [3 marks]
ii. Write short notes on the following constituents of milk.
Alkaline phosphate [3 marks]
Lipases in milk [3 marks]
Color/pigment of milk [3 marks]
c) i. Name any three lipids and their percentages of the total lipids in milk. [3 marks]
ii. Define the term “milk adulteration.” [2 marks]
iii. What is the main carbohydrate in milk and where does it comes from. [2 marks]
iv. Define the term “cow’s milk.” [1 mark]
Question Two – 20 Marks
a) Some people do not take milk due to its proteins. Discuss this statement indicating negative and positive attributes of milk proteins. [10 marks]
b) Explain the importance of the following adulterants in milk and simple way of detecting them in the dairy plants.
i. Hydrogen peroxide [3 marks]
ii. Starch [3 marks]
iii. Neutralizes [4 marks]
Question Three – 20 Marks
a) Discuss the importance of minerals as they relate to its osmotic pressure. [5 marks]
b) Discuss the functional properties of proteins and fats indicating the products in which they are important. [5 marks]
c) Discuss the oxidation/reduction potential of milk and how it is used in the assessment of milk quality. [10 marks]
Question Four – 20 Marks
a) A milk producer delivered milk that exhibited the following characteristics to the dairy plant.
i. Higher mineral content than normal milk. [3 marks]
ii. Higher fat content than normal milk [3 marks]
iii. Relatively normal but slightly higher levels of acidity. [4 marks]
With reasons identify the nature of the above milk and explain whether or not it should be accepted.
b) Discuss how various milk constituents influence its pH and levels of titratable acidity. [5 marks]
c) Discuss the synthesis and secretion of milk lipids. [5 marks]