Food Engineering assessment questions on “Principles of Semi-Moist Foods-2”.
1. The restraint imposed on the behavior of water is dependent on which of the following factors?
a) Nature and binding capacity of polar residues
b) Configuration of hydrophobic and hydrophilic areas
c) Mechanism which alters the structure of water
d) All of the mentioned
Answer: d
Clarification: All of the mentioned impose restraint on the behavior of water.
2. Which of the following is an advantage of semi moist food?
a) Ease in packaging and storage
b) Low in moisture, less bulky
c) Direct consumption and texture closer to normal food than dehydrated food
d) All of the mentioned
Answer: d
Clarification: All of the mentioned are advantages of semi moist food.
3. Which of the following law gives the relationship between the moles of water and the moles of solute in a solution and its water activity?
a) Hallinan law
b) Burgess law
c) Raoult’s law
d) None of the mentioned
Answer: c
Clarification: Raoult’s law gives the relationship between the moles of water and the moles of solute in a solution and its water activity.
4. Rice has a higher water activity than apples.
a) True
b) False
Answer: b
Clarification: Rice has a lesser water activity than apples. Apples contain higher water per 100 grams of dry material.
5. As the moisture content of a food decreases, a restraint is observed on the vapor pressure which is evident from the water activity.
a) True
b) False
Answer: a
Clarification: As the moisture content of a food decreases, a restraint is observed on the vapor pressure which is evident from the water activity.
6. Statement 1: When there is an equilibrium between the vapor pressure and the percentage relative humidity, water activity is directly proportional to the percentage relative humidity.
Statement 2: Even a water activity as high as 0.85 for food items is considered to be very dry for substances.
a) True, False
b) True, True
c) False, False
d) False, True
Answer: b
Clarification: When there is an equilibrium between the vapor pressure and the percentage relative humidity, water activity is directly proportional to the percentage relative humidity. Even a water activity as high as 0.85 for food items is considered to be very dry for substances.
7. Which of the following is true when a solute is added to water?
a) Concentration of water is increased
b) Interaction with solute may break or increase the water structures
c) None of the mentioned
d) Neither of the mentioned
Answer: b
Clarification: When a solute is added to water, concentration of water is reduced and interaction with solute may break or increase the water structures.
8. Statement 1: Sodium chloride has a higher water activity than sucrose.
Statement 2: Sucrose creates structures in water and reduces water activity below what they should be based on concentration alone.
a) True, False
b) True, True
c) False, False
d) False, True
Answer: b
Clarification: Sodium chloride has a higher water activity than sucrose. This is because sucrose creates structures in water and reduces water activity below what they should be based on concentration alone.
9. Statement 1: Just like the vapor pressure on an individual component is higher than when it is in bulk, the water activity is low when in bulk.
Statement 2: Water activity is directly proportional to the surface tension and molecular weight of water and inversely proportional to density of water.
a) True, False
b) True, True
c) False, False
d) False, True
Answer: b
Clarification: Just like the vapor pressure on an individual component is higher than when it is in bulk, the water activity is low when in bulk. Water activity is directly proportional to the surface tension and molecular weight of water and inversely proportional to the density of water.
10. If a dehydrated porous absorptive food is soaked in a solution whose viscosity is not too high to penetrate, then the food will absorb an amount of solution approximately equal to the amount of water it would normally absorb.
a) True
b) False
Answer: a
Clarification: If a dehydrated porous absorptive food is soaked in a solution whose viscosity is not too high to penetrate, then the food will absorb an amount of solution approximately equal to the amount of water it would normally absorb.
11. Semi moist food items work on the principle that the additives will diffuse into the food to an extent that the final concentration in the food and in the solution will be similar.
a) True
b) False
Answer: a
Clarification: Semi moist food items work on the principle that the additives will diffuse into the food to an extent that the final concentration in the food and in the solution will be similar.
12. Semi moist food items work on the principle of equilibrium, that is at a dry state, the food items absorb the solution and in the wet state, water is washed out with another liquid by diffusion.
a) True
b) False
Answer: a
Clarification: Semi moist food items work on the principle of equilibrium, that is at a dry state, the food items absorb the solution and in the wet state, water is washed out with another liquid by diffusion.
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