Principles Of Food Preservation Set 4

Mechanical Engineering

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This set of Principles of Food Preservation Multiple Choice Questions & Answers (MCQs) focuses on Principles Of Food Preservation Set 4

Q1 | In process annealing, heating is limited to avoid excessive oxidation.
  • true
  • false
Answer: true
Explaination:
in process annealing, the material is heated to revert the effects of work hardening by recovery and recrystallization and heating is done in such a way that
Q2 | Which of the following does not happen when a material is annealed?
  • internal stresses get relieved
  • increase in ductility
  • decrease in toughness
  • increase in softness
Answer: decrease in toughness
Explaination:
a material is annealed to relieve internal stresses, increase ductility, toughness and softness and produce specific microstructure.
Q3 | Which material is present above the upper critical temperature line in an iron carbon phase diagram?
  • martensite
  • pearlite
  • ledeburite
  • austenite
Answer: austenite
Explaination:
above the upper critical line in a iron carbon phase diagram, all the material is austenite while below the lower critical no austenite material exists.
Q4 | In stress relief annealing, the annealing temperature is relatively low.
  • true
  • false
Answer: true
Explaination:
the above statement is true. annealing temperatures are low in stress relief annealing so that the useful effects of cold working are not eliminated.
Q5 | Which of the following is not a type of annealing?
  • spherodizing
  • tempering
  • full annealing
  • stress-relief annealing
Answer: tempering
Explaination:
tempering is used to increase hardness by reheating and cooling the
Q6 | If fats and oils prevent bacteria spore formation and help in pore formation, why is it difficult to kill yeast in a salad dressing?
  • because the bacteria get stuck in the oil phase
  • this statement is incorrect
  • it is relative with respect to waster and hence better preserver
  • none of the mentioned
Answer: because the bacteria get stuck in the oil phase
Explaination:
it difficult to kill yeast in a salad dressing because the bacteria get stuck in the oil phase.
Q7 | Statement 1: With the increase in temperature, the enzyme gets deactivated. Statement 2: With the increase in temperature, the enzyme gets reactivated.
  • true, false
  • true, true
  • false, false
  • false, true
Answer: true, true
Explaination:
both the statements are true. this is because some enzymes like peroxide get reactivated after heating.
Q8 | Reeti subjected all of these enzyme based food items to heat. Which among these did not get deteriorated?
  • pickle with vinegar
  • pickle without vinegar
  • pear
  • tomato with slight salt
Answer: pickle with vinegar
Explaination:
all of the mentioned food items have enzyme peroxide in them. vinegar
Q9 | Which of the following food items is the lowest in heating up?
  • broths and thin soup with negligible starch in it
  • fruits packed in water/syrup with large pieces
  • evaporated milk
  • chopped vegetables with high starch content packed with free liquid
Answer: chopped vegetables with high starch content packed with free liquid
Explaination:
broths and thin soup with loads of starch in it. the starch in these solids
Q10 | Which of the following comes under the categories of food – broken curve heating food?
  • evaporated milk
  • fruits packed without water/syrup
  • syrup packed with sweet potatoes
  • all of the mentioned
Answer: syrup packed with sweet potatoes
Explaination:
in syrup packed with sweet potatoes, the heat transfer is through convection initially. but when the starch particles from the solids separate, they retard the heat transfer.
Q11 | Statement 1: In a thermocouple, two wires are of different materials and a voltage difference is created due to the conduction of each material at the juncture and this gives us the difference in temperature in both metals and hence the temperature of the liquid. Statement 2: The zone of slowest heating in a container is called cold point of a container.
  • true, false
  • true, true
  • false, false
  • false, true
Answer: true, true
Explaination:
in a thermocouple, two wires are of different materials and a voltage difference is created due to the conduction of each material at the juncture and this gives us the difference in temperature in both metals and hence the temperature of the liquid. all points inside a container do not heat up at
Q12 | For canning technology, the cold point of the can is determined by soldering stuffing boxes and different depths in different boxes, a thermocouple in each box and a potentiometer in each box.
  • true
  • false
Answer: true
Explaination:
for canning technology, the cold point of the can is determined by soldering stuffing boxes and different depths in different boxes, a thermocouple in each box and a potentiometer in each box.
Q13 | The period of time elapsed from placing the cans into the retort and starting to heat until the retort reaches processing temperature is termed as  
  • slope of cooling curve, fc
  • slope of heating curve, fh
  • zero time
  • come-up-time
Answer: come-up-time
Explaination:
the period of time elapsed from placing the cans into the retort and starting to heat until the retort reaches processing temperature is termed as come- up-time.
Q14 | Which of the following is a synonym for loss factor of food?
  • loss tangent
  • dielectric loss
  • loss tangent & dielectric loss
  • none of the mentioned
Answer: loss tangent & dielectric loss
Explaination:
loss factor of food is called loss tangent and dielectric loss.
Q15 | Which of the following is true about loss factor of food?
  • it is desirable quality of food
  • it is the ability of food to absorb waves
  • it is represented by Ɛ
  • all of the mentioned
Answer: all of the mentioned
Explaination:
all the given factors are true about loss factor.
Q16 | Penetration depth of food refers to the depth inside the food inside which the heat generation drops to 37%.
  • true
  • false
Answer: true
Explaination:
penetration depth of food refers to the depth inside the food inside which the heat generation drops to 37%.
Q17 | Which of the following is untrue?
  • it is difficult to predict the electric field intensity inside a food material
  • design of oven plays an important role in determining the electric filed intensity in a food material
  • orientations of microwaves is an important role
  • none of the mentioned
Answer: none of the mentioned
Explaination:
it is difficult to predict the electric field intensity inside a food material. design of oven plays an important role in determining the electric filed intensity in a food material. orientations of microwaves is an important role.
Q18 | Hannah heats refrigerated rice which has been devoid of moisture and become dry. She heats it in a microwave. It gets unevenly heated. What should she do?
  • water should be added for even heating
  • she should heat it using equipment that offers conduction or convection
  • none of the mentioned
  • all of the mentioned
Answer: water should be added for even heating
Explaination:
water has a low dielectric constant due to the generation of friction due to rotation of dipoles. hence, water should be added for even heating.
Q19 | One disadvantage of microwave cooking is that the energy efficiency in this process is less.
  • true
  • false
Answer: false
Explaination:
microwave cooking has very high energy efficiency.
Q20 | Although microwave heating can be used for drying of food containing uneven water content, it is isn’t done for certain food products like garlic. Why?
  • no pasteurization
  • essential oils being stripped off
  • none of the mentioned
  • no pasteurization & essential oils being stripped off
Answer: no pasteurization & essential oils being stripped off
Explaination:
for drying of garlic, the essential oils which are the volatile components of the garlic are stripped off from it.
Q21 | Microwave heating is good for puffed products. Why?
  • the rate of heat transfer is less than the rate of moisture loss
  • the heat transfer in these food items takes place so fast that instead of shrinking of the food items due to loss of moisture content, they stay intact and hence puffed
  • none of the mentioned
  • all of the mentioned
Answer: the heat transfer in these food items takes place so fast that instead of shrinking of the food items due to loss of moisture content, they stay intact and hence puffed
Explaination:
the heat transfer in these food items takes place so fast that instead of shrinking of the food items due to loss of moisture content, they stay intact and hence puffed.
Q22 | Which of the following is NOT a part of the microwave heating system?
  • magnetron
  • anode
  • cathode
  • none of the mentioned
Answer: none of the mentioned
Explaination:
all the given above are parts of a microwave heating system.
Q23 | Recently, cancer causing effects, nutritional destructions of food and biological effects of exposure of microwave heating has come into light.
  • true
  • false
Answer: true
Explaination:
recently, cancer causing effects, nutritional destruction of food and biological effects of exposure of microwave heating has come into light.
Q24 | 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?
  • hallinan law
  • burgess law
  • raoult’s law
  • none of the mentioned
Answer: raoult’s law
Explaination:
raoult’s law gives the relationship between the moles of water and the moles of solute in a solution and its water activity.
Q25 | Rice has a higher water activity than apples.
  • true
  • false
Answer: false
Explaination:
rice has a lesser water activity than apples. apples contain higher water per 100 grams of dry material.
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