fats and oils

Question 1

bond in triglyceries?

Answer 1

ester

Question 2

phospholipid structure

Answer 2

same as TGLYC except one FA is replaced by a phosphate and nitrogenous base

important for emulsification

Question 3

sterols

Answer 3

C rings with side chains

• only in animal sources
• not an essential nutrient
• phytosterols: found in plants

Question 4

2 types of rancidity?

Answer 4

1. hydrolytic: from exposure to h2o
   - catalyzed by heat and lipase
   - TG is hydrolyzed to smaller subunits
2. oxidative: exposure to o2
   has 3 steps:
   -initiation: free radical is formed
   -propagation: o2 combines w/ free radical = peroxide free radical is formed
   -termination: no more H at DB to react with O2

Question 5

expeller vs cold pressed oil

Answer 5

cold pressed:

• no heat = doesnt destroy nutrient
• high quality
• more unstable

expeller:

• high heat (loss of nutrrients)
• bigger yield but more expensive

Question 6

refined vs unrefied oils

Answer 6

unrefined:

• pressed
• stronger taste
• not processed

refined:
-chemically processed to remove undesirable components
-higher mp
-

Question 7

catalyst in hydrogenation?

Answer 7

nickel

Question 8

what is interesterification?

Answer 8

rearragning FA portion of TG on glyerol backbone

advantage: can modify properties without transf FA

Question 9

what is winterization?

Answer 9

cooking oils at low temp

solids are separated by filters

Question 10

what is fractionation

Answer 10

similar to winterization

Question 11

functions in food

Answer 11

emulsion
nutrients
satiety
heat transfer

Question 12

what happens if you deep fry multiple times?

Answer 12

particles and contaminants lowers smoke point

if doesn’t get replaced = carcinogenic

Question 13

do refined or unrefined have lower smoke point?

Answer 13

unrefined

more refined = more stable