FATS 2 Flashcards

1
Q

whats the smoke point?

A

(350-450°F): temperature at which fat or oil
begins to smoke

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2
Q

whats flash point

A

(~600°F): temp at which wisps of fire streak
the surface of heated fat or oil

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3
Q

whats the fire point

A

(~700°F): temp at which heated substance
bursts into flames and burns for >5 sec

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4
Q

wat are triglycerides

A

glycerol + fatty acids

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5
Q

whats glycerol

A

acrolein smoke with sharp, offensive odor

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6
Q

how should fats be fried

A

stable heat in 100% fat; smoke point above 420F

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7
Q

what should you avoid when frying

A

surface moisture and temps that are too low (below 375 may lead to excessive fat absorption)

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8
Q

why should particles of food or breading that break off be
filtered out daily?

A

Darken oil’s color and lower smoke point

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9
Q

Why do foods fry best in oil that has been used at
least once?

A

because oils pick up proteins and sugars from foods
that have been fried in them
+ provide substrates for the Maillard reaction

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10
Q

what has to be broken to release the fat so it can lump
together and be churned into butter

A

Phospholipid layers emulsifying the fat globules in milk

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11
Q

whats used to make butter

A

Cream that floats to the top from unhomgenized milk

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12
Q

what does milk fat consist of

A

triglycerides surrounded by protein + phospholipid membrane

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13
Q

what does milk fat membrane allow for

A

dispersion of fat in
aqueous phase

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14
Q

whats maragine made from

A

partially hydrogenated vegetable oils

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15
Q

whats shortening made from

A

Plant oils that have been hydrogenated to become more
solid and pliable

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16
Q

what are the three extraction methods for oils

A

cold-pressing, expeller-pressing, chemical solvents

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17
Q

whats cold pressing

A

mechanical pressing
*Usually, unrefined

18
Q

whats expeller pressing

A

squeezing at very high pressures

19
Q

how do chemical solvents work

A

chemical removal using non-polar (fat-soluble) solvent
*Majority of commercial vegetable oils

20
Q

describe the flavor, nutritional value, smoke point and rancidity of unrefined oils

A

full flavor of the plant source
*Slightly higher nutritional value
*Have low smoke point, can’t expose to high heat
*More prone to rancidity (lower shelf-life)

21
Q

describe the smoke point, aroma and flavor of refined oils

A

*Low-aroma, bland-flavor
*Higher smoke points

22
Q

whats removed from refined oils

A

naturally present gums,
resins, pigments, soil, free fatty acids

23
Q

why do some oils partially crystalize when stored in the fridge

A

because some fatty acids have higher melting points

24
Q

what does partially crtsalzing create

A

cloudiness (still perfectly edible and reversible
at warmer temps)

25
Q

whats winterization the removal of

A

removal of high-melting point
triglycerides to prevent cloudiness at cold temps

26
Q

what are fat mimetics

A

mimic sensory and/or physical properties

27
Q

what are fat mimetic based from

A

carb- or protein-based
*Cannot replace fat on one-to-one basis

28
Q

what do carb-based fat replacers bind

A

water, swell, mimic texture, mouthfeel, and opacity fat

29
Q

what are protein-based fat replacers broken into

A

microscopic particles that mimic mouthfeel and
texture of fat

30
Q

Olestra (Olean®) is a lipid-based fat replacer that is so big it cannot be digested. what is it made of

A

glycerol portion of triglyceride is replaced with sucrose which can bind 6,7, or 8 fatty acids

31
Q

what are the two types of rancidity

A

hydrolytic and oxidative

32
Q

what does water break down in hydrolytic ranicty

A

large fat molecules into smaller ones

33
Q

what does the the double bond of unsaturated fatty acid reacting with oxygen in oxidative rancidity result in

A

two or more shorter
molecules

34
Q

when does hydro rancidity occur

A

if food is not rid of surface moisture, or from
water found on frozen food to be fried

35
Q

what is hydro rancidity catalyzed by

A

lipases and heat

36
Q

when does oxidative randcity occur

A

when food is exposed to oxygen in the air

37
Q

what increases suspectidty to randicidty in oxidative

A

Higher degree of unsaturation

38
Q

whats the first step of oxidative rancidity

A

Initiation: formation of free radical

39
Q

what occurs during the second step

A

Propagation: free-radical chain reactions

40
Q

what occurs during the third step

A

Termination: formation of non-radical products