Water Pt. 3

Question 1

Slow Freezing Causes

Answer 1

Few Nuclei
Rapid crystal growth
A few large ice crystals
(causes cell rupture)

Question 2

• Frozen ruptured cells when thaw cause an

Answer 2

increase of Aw

Question 3

Rapid Freezing Causes

Answer 3

Numerous Nuclei
Less Rapid crystal growth
Lots of small ice crystals

Question 4

Where does nucleation start

Answer 4

the point of imperfection

Question 5

*Freeze drying can allow you to

Answer 5

rehydrate cells due to some cells not being ruptured due to the formation of ice crystals

Question 6

Freezing Involves

Answer 6

+ Formation of Ice Crystals

+ Further concentration of unfrozen portion

+ Glass State

Question 7

Tg

Answer 7

Glass Transition Temperature

Question 8

Forms of Water (Food)

Answer 8

+ Constitutional (Water of Hydration)

+ Bound (monolayer & multilayer)

+ Free (Bulk Phase)-(Capillary)

Question 9

Raoult’s Law

Answer 9

Xh2o = 1 – Xs

Where Xs = n(solute) / n(solute) + n(hso)

Question 10

Isotherms

Answer 10

Curve that describes (specific moisture/constant temp) relation of amount of H2O sorbed by food constituents and vapor pressure or relative humidity (Aw)

Question 11

Desorption

Answer 11

Dehydration

Question 12

Asorption

Answer 12

Rehydration

Question 13

Hysteresis Effect

Answer 13

The difference between dehydration and rehydration

Question 14

Hygroscopic

Answer 14

Wants to bound to water