1. Most Heat sensitive vitamin in milk is?
a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D
Discussion
Explanation: Vitamin C is the most heat sensitive vitamin in milk among all others. Milk is a rich source of Vitamin A& D
2. Effect of Pasteurization on Vitamins in Milk ___________
a) Great loss
b) Little or no loss
c) Denature
d) Sublime
Discussion
Explanation: Pasteurization in a plate heat exchanger can however, be accomplished with virtually no loss of vitamin C. The other vitamins in milk suffer little or no harm from moderate heating
3. Which of the following mineral is affected by heat treatment in milk?
a) Calcium
b) Potassium
c) Hydroxyphosphate
d) Zinc
Discussion
Explanation: Of the minerals in milk only the important calcium hydroxyphosphate in the casein micelles is affected by heating. Rest has no effect on heating.
4. Heat treatment on minerals results leads to ___________
a) Clumps formation
b) Bubble formation
c) Foul smell
d) Loss of cheese making characteristics
Discussion
Explanation: When heated above 75°C the substance loses water. Loss of water leads to the formation of insoluble calcium orthophosphate; which impairs the cheese making properties of the milk.
5. Why is it necessary to study flow behavior in dairy?
a) To design food processing plant
b) To prevent spoilage
c) To design food processing plant and prevent spoilage
d) For nutrition
Discussion
Explanation: Study of flow behavior is important for the designing of a food processing plant. In the dairy industry; in particular, there are cream and cultured milk products whose characteristics can be partially or completely spoiled if their flow behavior is not understood
6. The science of deformation and flow of matter is called _____
a) Welding
b) Bending
c) Tapping
d) Rheology
Discussion
Explanation: Rheology is defined as the science of deformation and flow of matter. Bending is one of the flow behaviors.
7. Consistency can be described as ___________
a) Viscosity
b) Elasticity
c) Breakability
d) Viscosity and elasticity
Discussion
Explanation: Rheologically the consistency is described by two components, the viscosity (“thickness”, lack of slipperiness) and the elasticity (“stickiness”, structure). Breakability is the quality of being easily damaged or destroyed.
8. Rheology stands for viscosity measurements, characterisation of flow behavior and determination of material structure.
a) True
b) false
Discussion
Explanation: Rheology involves viscosity measurements; it involves characterization of flow behavior and determination of material structure. Basic knowledge of these subjects is essential in process design and product quality evaluation.
9. The time required to reduce stress in the material by flow is called __________
a) Peak time
b) Relaxation time
c) Stress time
d) No time
Discussion
Explanation: One way of characterizing a material is by its relaxation time, i.e. the time required to reduce stress in the material by flow. It is important to study the flow behavior of the milk.
10. Milk is a ______ fluid.
a) Viscous
b) Elastic
c) Visco-elastic
d) Extraneous
Discussion
Explanation: Gases and liquids are normally described as viscous fluids. An ideal viscous fluid is unable to store any deformation energy.