Fats and Oils

Question 1

what are lipids used for in food?

Answer 1

frying, formation, to finished products (ex. butter on bread)

Question 2

triglyceride structure:

Answer 2

a glycerol attached to three fatty acids

Question 3

trans fatty acids have hydrogens on ___ of the double bond, cis fatty acids have hydrogen bonds on ___ of the double bond

Answer 3

opposite sides/the same side

Question 4

linoleic: omega-___, alpha-linolenic; omega-___

Answer 4

6/3

Question 5

physical properties are affected by:

Answer 5

chain length, saturation, cis/trans configuration

Question 6

phospholipid structure:

Answer 6

glycerol, two fatty acids, one phosphate group

Question 7

what are the two types of emulsions?

Answer 7

oil in water and water in oil

Question 8

sterols

Answer 8

interconnected C rings with varying side chains

Question 9

plant sterols are thought to do what to cholesterol?

Answer 9

lower it

Question 10

waxes

Answer 10

long fatty acid and alcohol hydrocarbon chains

Question 11

what are waxes used for?

Answer 11

coating fruits and vegetables to hold in moisture and prevent damage during transport

Question 12

smoke point is lowered by:

Answer 12

unrefined oils, reuse

Question 13

you can store MUFA/refined oils ___, PUFA/unrefined ___, refrigerate ___, ___, ___, ___

Answer 13

~1yr/~6mo

PUFA, butter, margarine, unrefined oils

Question 14

rancidity

Answer 14

chemical deterioration causing off smells and flavours, caused by light, heat, and O2

Question 15

what are the two types of rancidity?

Answer 15

hydrolytic (when exposed to water, heat, or lipase the bonds in triglycerides break) and oxidative (free radicals are formed in initiation, combined with O2 to make peroxides in propagation and used up in termination when all the H are gone)

Question 16

antioxidants:

Answer 16

combat free radicals by being oxidized, donating H, or sequestering metals)

Question 17

oil extraction is ___ (higher yield, potential nutrient loss) or ___ (either ___ or ___ pressed)

Answer 17

chemical

mechanical/cold/expeller

Question 18

refined

Answer 18

chemicals and physically processed after pressing to remove any undesirable compounds

Question 19

unrefined

Answer 19

not processed after pressing

Question 20

options for refinement and what they remove:

Answer 20

degumming (phospholipids), neutralization (free fatty acids), bleaching (colour), deodorization (colour, flavour, free fatty acids), winterization (waxes)

Question 21

hydrogenation

Answer 21

hardens vegetable oils by adding H to double bonds, may produce trans fatty acids

Question 22

interesterification

Answer 22

rearrangement of fatty acid on the glycerol to change the physical properties without creating trans fatty acids

Question 23

winterization

Answer 23

oils are cooled for a long period of time and any solids that form are removed

Question 24

fractionation

Answer 24

a more sophisticated version of winterization with moe specific results

Question 25

functions of lipids in food:

Answer 25

heat transfer, shortening, emulsion, flavour, texture, satiety, nutrients

Question 26

tips for low fat cooking:

Answer 26

use nonstick pans or parchment paper, pick lean cuts, trim any visible fat, choose other cooking methods instead of frying, choose healthier fats

Question 27

in baking what can be used to replace fats?

Answer 27

apple sauce, banana, beans, shredded zucchini, tofu

Question 28

coconut oil has a middle melting point because:

Answer 28

high saturated fatty acids but mostly medium chains