Principles Of Food Preservation(Engineering > Food Engineering ) Questions and answers for exam Preparation

Question 1. Which of the following is true about spore formation by cells?

They enlarge and prevent external agents from entering inside
A resisting state from unfavorable environment
They are formed by healthy cells that face starvation
All of the mentioned

Explanation:-

Answer: Option D. -> All of the mentioned
Answer: (d).All of the mentioned

Question 2. The x-axis shows the temperature and the y-axis shows the killing time. This is with respect to spores in a suspension. Curve a = 100,000 spores/ml and b= 1,000 spores/ml. Above curve a is the region of spores killed and below the region b is the region of spores survived. Which of the following do we comprehend from the above?

Greater the spore concentration, more heat resistant the suspension
Spores of a given strain, all have the same heat resistance
Spores of the same strain have many spores of low heat resistance
Spores of the same strain have very few spores of high heat resistance

Explanation:-

Answer: Option A. -> Greater the spore concentration, more heat resistant the suspension
Answer: (a).Greater the spore concentration, more heat resistant the suspension

Question 3. What could be the possible reason for the minimal use of MSG in preserved/ canned food items?

Reduction in spore formation
Increase in spore formation
Facilitating multiplication of bacteria
None of the mentioned

Explanation:-

Answer: Option A. -> Reduction in spore formation
Answer: (a).Reduction in spore formation

Question 4. Which of the following sentences is NOT true?

Bacteria can be killed by treating with heat, both, dry and moist heat treatment
Cell protein coagulates in the absence of air
Order of death by moist heat is logarithmic in nature
None of the mentioned

Explanation:-

Answer: Option B. -> Cell protein coagulates in the absence of air
Answer: (b).Cell protein coagulates in the absence of air

Question 5. The non-functioning of the enzymes in bacteria is a major reason of death of bacteria.

True
False
May be True or False
Can't say

Explanation:-

Answer: Option B. -> False
Answer: (b).False

Question 6. The rate of destruction of an organism per minute at any given temperature in a process is the reciprocal of the time in minutes.

True
False
May be True or False
Can't say

Explanation:-

Answer: Option A. -> True
Answer: (a).True

Question 7. For the thermal death time curve, C= minutes to destroy the organism at 121 °C. Z= slope of thermal death time curve in °C and T= temperature under consideration and t= time taken to destroy. Then, which of the following represents the lethal rate at T?

C
T
t/C
C/t

Explanation:-

Answer: Option D. -> C/t
Answer: (d).C/t

Question 8. Statement 1: In thermal death time curve, after plotting C/t values from it, C value should be equal to C₀ value.
Statement 2: When C₀ value versus process time in minutes is plotted on a linear graph paper, a straight line is obtained.

True, False
True, True
False, False
False, True

Explanation:-

Answer: Option B. -> True, True
Answer: (b).True, True

Question 9. For the thermal death time curve, C= minutes to destroy the organism at 121 °C. Z=slope of thermal death time curve in °C and T= temperature under consideration and t= time taken to destroy. Which of the following is read from the graphs?

C
z
t/C
C/t

Explanation:-

Answer: Option C. -> t/C
Answer: (c).t/C

Question 10. By plotting the C/t values obtained from a thermal death time curve, a curve is obtained. How is the lethal value obtained from this curve?

Area under the curve
The center point on the x-axis with respect to beginning and end of curve and then extends to the curve
The center point on the y-axis with respect to beginning and end of curve and then extends to the curve
None of the mentioned

Explanation:-

Answer: Option A. -> Area under the curve
Answer: (a).Area under the curve