Food Science Answers for Desklib

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Food Science Answers

1. Which of the following is NOT applied for food preservation?
A. Storage at 37°C
B. Addition of salt or sugar
C. Fermentation of food materials
D. Control of concentration of O2 and CO2 present in the package
2. An evaporator is used to concentrate fresh milk containing 3.7% fat and 13.0% total solids to a
product containing 18.0% fat. What is the total solids concentration in the final product?
A. 44.1% B. 57.1% C. 63.2% D. 64.0%
3. Refer to question 2 above, what is the yield of product from 2000 kg of fresh milk assuming there are
no losses of solids?
A. 219 kg
B. 285 kg
C. 411 kg
D. 813 kg
4. A juice squash is produced by mixing fruit juice and sugar syrup. Calculate how much apple juice at
15% sugar content, and sugar syrup at 60% sugar content will be needed to produce 1125 g of
fresh fruit squash containing 25% sugar.
A. 250 g apple juice and 875 g sugar syrup

B. 750 g apple juice and 375 g sugar syrup
C. 825 g apple juice and 300 g sugar syrup
D. 875 g apple juice and 250 g sugar syrup
5. During production of milk, pasteurisation is used on the milk for:
A. Destruction of wild yeast
B. Develop pasteurize flavor and taste
C. Destruction of pathogenic microorganisms
D. All of the above
6. In heat processing, the term z-value is the temperature change required to bring about a ten-fold
change in the decimal reduction time of microorganisms.Given that: z-value = (T2-T1)/(log D1 –
log D2). Which of the following statements is correct?
A. T is thermal resistance time and D is 10% reduction time for a surviving population to be reduced by 1
log cycle.
B. T is the given temperature for a surviving population to be reduced by 1 log cycle and D is the
decrease in population of spores.
C. T is the temperature and D is the decimal reduction time at a given temperature for a surviving
population to be reduced by 1 log cycle.
D. None of the above
7. F and F0 values are used to calculate the process time in sterilisation. F0 is obtained:
A. At any temperature and z-value

B. At a reference temperature and D-value
C. At a reference temperature and z-value
D. At a reference temperature and L-value
8. In an evaporator, separation is achieved by exploiting:
A. The difference in solubility between solutes
B. The difference in melting point between water and solutes
C. The differences in volatility between water and solutes
D. The difference in vacuum pressure between water and solutes
9. Which of the following are taken into account when selecting a suitable evaporator?
A. Properties of the product
B. Required product quality
C. Degree of concentration
D. All of the above
10. Concentration process in food processing refers to a reduction of water in which of the following?
A. Solid foods
B. Liquid foods
C. Liquid and some types of solid foods
D. All types of foods
11. In comparison to evaporation, membrane processing has:
A. Lower capital cost

B. Higher volatiles retention
C. Higher yields due to no fouling
D. Significant damage to vitamins
12. The drying efficiency of thermoplastic foods can be enhanced by using the following techniques,
EXCEPT:
A. Cold zones
B. BIRS spray-drying
C. Freeze drying
D. Rotating disk
13. BIRS spray dryers utilize countercurrent cool, dry air of about:
A. 25°C and 3% relative humidity
B. 30°C and 2% relative humidity
C. 30°C and 3% relative humidity
D. 35°C and 3% relative humidity
14. What is the maximum obtainable concentration in a typical freeze concentration process?
A. 45% B. 48% C. 65% D. 85%

15. Which of the following is NOT an example of a chemical change occurring in foods during
dehydration?
A. Loss of elasticity
B. Maillard browning
C. Protein denaturation
D. Loss of vitamins
16. Most dehydration methods involve which of the following processes?
I. Drying by hot air, process
II. Drying by heated surfaces,
III. Freeze drying
IV. Concentration
A. I, II and III only
B. I and II only
C. I, II, III and IV
D. III and IV only
17. Which of the following is NOT a heated-surface dryer?
A. Conveyor belt dryer
B. Vacuum shelf dryer
C. Ball dryer
D. Drum dryer