chapter 11

Question 1

define lipid

Answer 1

non-polar
water soluble
composed of CHO

Question 2

define fats

Answer 2

solid at room temp

Question 3

define oils

Answer 3

lipid at room temp

Question 4

define triglycerides

Answer 4

composed of glycerol and 3 fatty acids

Question 5

define glycerol

Answer 5

3 carbon molecules with 3 hydroxyl groups can be esterified

Question 6

define fatty acids

Answer 6

chain of carbons with characteristics of carbonyl groups

can be esterified to carboxyl group

Question 7

define short-chain fatty acids

Answer 7

6 carbons or less

Question 8

medium- chain fatty acids

Answer 8

8-10 carbons

Question 9

long chain fatty acids

Answer 9

12+ Carbons

Question 10

define saturated fatty acids

Answer 10

no double bonds (Stearic acid)

Question 11

define monounsaturated

Answer 11

has 1 double bond (oleic acid)

Question 12

define polyunsaturated

Answer 12

2 double bonds (linoleic acid)

Question 13

define non-conjugated PUFA

Answer 13

there is a CH2 group between the double bonds

Question 14

Define conjugated PUFA

Answer 14

no CH2 group between the double bonds

Question 15

list the omega 3 fatty acids

Answer 15

1. Alpha-linolenic acid
2. Eicosapentanoic acid
3. Docosahexaenoic acid

Question 16

list the sources of Omega 6 fatty acids

Answer 16

1. Linoleic acid
2. gamma- linolenic acid
3. arachidonic acid

Question 17

Describe cis fatty acids

Answer 17

h’s are on same sides of the double bond

Question 18

Describe trans fatty acids

Answer 18

H’s are on different sides of the double bond

Question 19

Describe conjugated linoleic acid

Answer 19

has both cis and trans double bonds

Question 20

melting point

Answer 20

temperature at which the crystals of a solid fat melt

Question 21

simple fats

Answer 21

contain glycerol and fatty acids

Question 22

monoglycerides

Answer 22

1 glycerol + 1 fatty acid

Question 23

diglycerides

Answer 23

1 glycerol +2 fatty acids

Question 24

triglycerides

Answer 24

1 glycerol +3 fatty acids

Question 25

Alpha crystals

Answer 25

very fine, extremely unstable, melt quickly, recrystallize into B' crystals

Question 26

Beta' crystals

Answer 26

moderately stable, extremely smooth, *desired form for baking--> fine texture

Question 27

intermediate crystals

Answer 27

grainy *NOT RECOMMENDES for baking can form B' crystals (melt and recrystallize)

Question 28

beta crystals

Answer 28

coarsest crystals, extremely stable, formed when fat melts completely and recrystallize WITHOUT being disturbed fat becomes OPAQUE

Question 29

oxidative rancidity

Answer 29

degradation of a fat by oxygen in the air (double bonds cleaved in unsaturated fats by free radicals)

Question 30

oxidative rancidity

Answer 30

degradation of a fat by oxygen in the air (double bonds cleaved in unsaturated fats by free radicals)

Question 31

hydrolytic rancidity

Answer 31

lipolysis (hydrolysis) of lipids to free fatty acids and glycerol

Question 32

antioxidants

Answer 32

provide a hydrogen atom to react with a free radical of a fatty acids or with a peroxide that has already formed (MAJOR IMPACT)

Question 33

lipolysis

Answer 33

hydrolysis

Question 34

Reversion

Answer 34

oxidation of linoleic acids

Question 35

Smoke point

Answer 35

temp at which fat or oil will emit smoke 600

Question 36

acrolein:

Answer 36

compound make from the break down of glycerol when oil is over heated, irritant -sharp offensive odor

Question 37

polymerization

Answer 37

process in which free fatty acids link together | especially when over heated--> gummy dark residue +oil becomes more viscous and prone to foaming

Question 38

flash point

Answer 38

temp at which tiny wisps of fire streaj to the surface of a heated substance

Question 39

fire point

Answer 39

temperature at which a heated substance (oil) burst into flames and burns for at least 5 seconds

Question 40

which portion of a glycerol molecule can be esterified?

Answer 40

hydroxyl

Question 41

which portion of a fatty acid attaches to glycerol during esterification?

Answer 41

carboxyl

Question 42

what is esterification?

Answer 42

the removal of H2O to form a triglyceride

Question 43

what is lipolysis?

Answer 43

hydrolysis

Question 44

what is added and removed during these process (esterification)

Answer 44

added: a bond removal: is a water molecule

Question 45

know how to name /Interpret the name of a fatty acid using simple chemical short hand

Answer 45

shorthand: Palmitic acid (16:0) first number is the # of carbons second # is the number of double bonds

Question 46

what are 3 characteristics by which fatty acids can vary? | determine the melting point, stability solubility physical properties

Answer 46

1. chain length 2. presence/ # of double bonds 3. cis-trans

Question 47

• What two types of fatty acids are essential nutrients and why?

Answer 47

Omega 3&6= double bonds before the 9th carbon

Question 48

What are the food sources of omega-3 and omega-6 fats? (extra credit only 😊)

Answer 48

3: oil fish and flaxseed 6: nuts, wheat germ, oils

Question 49

How do fatty acid chain shapes vary between cis, trans, and saturated fatty acids?

Answer 49

because it varies depending on the hydrogen location around the double bond (CHEMICAL DIFFERENCES)

Question 50

What are the general structural characteristics of naturally-occurring fatty acids?

Answer 50

Cis- bent structure at the double bond

Question 51

What factors increase and decrease melting point?

Answer 51

Increase melting point= longer chain length, saturation (no double bonds), trans double bonds Decrease melting point= shorter carbon chains, higher degree of unsaturated, Cis double bonds

Question 52

What types of fats are more likely to be solid vs. liquid? Why?

Answer 52

Fats found as solid and why? Palmitic acid highly saturated

Question 53

which types of fatty acids/ are not soluble in water? | *what is the exception*

Answer 53

short/ medium/ long chain fatty acids are not very soluble Butyric acid is soluble in water

Question 54

• Do all 3 fatty acids esterified to a glycerol molecule in a triglyceride have to be the same?

Answer 54

yes

Question 55

what types of fat crystals are most desirable? How are they formed?

Answer 55

Beta' | formed by agitating during cooling

Question 56

What are the steps involved in oxidative rancidity? what products are formed from oxidative rancidity

Answer 56

Initiation- radical formation Progression- radicals react and transfer their unpaired electron to other compounds Termination- 2 radicals combine to stop the reaction

Question 57

How is oxidative rancidity facilitated or prevented?

Answer 57

facilitated by: 1. certain metals 2. light 3. oxygen 4. warm temperature prevented by: 1. proper storage 2. antioxidants (major impact)

Question 58

What can cause hydrolytic rancidity?

Answer 58

high temp | catalysis of lipases

Question 59

what product is made from hydrolytic rancidity?

Answer 59

free fatty acids and glycerol by water

Question 60

What is the result of reversion? Which fatty acids does it pertain to?

Answer 60

Produce: fishy or beany smelling oil | Linolenic acid