Freezing

Question 1

List preservation methods

Answer 1

1) freezing

2) salting

3) canning

4) drying

5) refrigerating

Question 2

Slow freezing =

Answer 2

1) Few nuclei, nucleation will begin where any impurities in the product container or product are

2) rapid crystal growth

3) a few large ice crystals which can cause cell to burst

Question 3

Rapid freezing =

Answer 3

1) numerous nuclei

2) less rapid crystal growth

3) lots of ice crystals, cells retain their structure, product can be rehydrated

Question 4

What are the three forms of water in food?

Answer 4

1) Constitutional

2) Bound (mono layer and multilayer)

3) Free

Question 5

What are isotherms?

Answer 5

Curve that shows the relationship between water activity and moisture content in a food product at a constant temperature and pressure

Question 6

What are the 2 sorption isotherms ?

Answer 6

1) desorption (dehydration)

2) adsorption (rehydration)

Question 7

What is the hysteresis effect?

Answer 7

The relationship between desorption and adsorption

Question 8

What does hygroscopic mean ?

Answer 8

Wants to bind water

Question 9

What does oxygen do in water?

Answer 9

Oxygen in water creates reactions, often undesirable