1
Q
heat of fusion or solidification
A
- at freezing point, 1 grams of water requires 80 CALORIES of energy to be withdrawn
2
Q
heat of vaporation
A
- at boiling point, 1 grams of water requires 540 CALORIES of energy to change to steam
3
Q
water activity
A
- the ratio of the vapor pressure of a food sample (p) to the vapor pressure of pure water at the same temperature
- amount of free water in a food
4
Q
solution
A
- when solute molecules completely dissolve in a solvent without precipitating out
5
Q
saturated solution
A
- solution that has the maximum amount of solute that can be dissolved in the solvent
6
Q
dispersion
A
- formed when substances called colloids are too large to dissolve in a solvent
- instead, they remain in the solvent as an unstable dispersion
- classified as suspensions or emulsions
7
Q
suspension
dispersion
A
- large colloidal molecules remain suspended in the media and are visibly distinct, such as when starch is suspended in cold water
8
Q
emulsion
A
- colloidal particles disperse completely within the medium (the second phase)
- milk, mayonnaise, gravies are examples
9
Q
hydrolisis
A
- chemical reaction where a water molecule is used to split a compound into simpler molecules
10
Q
carbohydrates
A
- one of four major classes of nutrients
- energy: 4 calories per gram
11
Q
glycogen
A
- primary carbohydrate in animal tissue
12
Q
cryoprotectant
sucrose
A
- a molecule that protects biological tissue against structural damage (due to ice formation) during freezing and thawing
13
Q
starch gelatinization
A
- the loss of molecular organization within starch granules characterized by irreversible swelling and loss of birefringence
14
Q
starch gelation
A
- process whereby amylose molecules leach out of the starch granules and form intermolecular hydrogen bonds
- result is a three-dimensional network of amylose molecules with entrapped water and starch granules
- responsible for the texture of many sauces and puddings
15
Q
syneresis
A
- “weeping” of a starch gel due to rapid heating or cooling
16
Q
resistant starch (RS)
A
- starch that cannot be enzymatically digested by humans
17
Q
dietary fiber
A
- carbohydrates and lignin that are intrinsic to a plant’s structure but that are indigestile by human digestive enzymes
18
Q
functional fiber
A
- indigestible carbohydrates that have been isolated, extracted, or manufactured and that have been clinically proven to have a physiological benefit
19
Q
cellulose
A
- a homo-polysaccharide of glucose that is indigestible by human enzymes
- predominant component of plant cell walls
- no caloric contribution
20
Q
temporarily hard water
water hardness
A
- contains bicarbonate salts
- precipitates after boiling
21
Q
permanently hard water
A
- contains calcium and magnesium sulfates
- does not precipitate
