Unit 5 Flashcards
(118 cards)
1
Q
Organic compound soluble in organic solvents but not in water.
Composed of carbon, hydrogen and oxygen
A
Lipid/fat
2
Q
What are the roles of fats in foods
A
Provide essential nutrients
Provide concentrated source of energy & raw materials for making needed products
Provide taste smell and texture to foods
Stimulate appetite and contribute to feelings of fullness
Heat transfer without burning food during heat transfer
3
Q
How does fat bc part of our food
A
Added at food processing
Added at food prep
Added at table
Found naturally in foods
4
Q
3 major classifications if lipids
A
Triacylglycerols/triglycerides
Phospholipids
Sterols
5
Q
What are triglycerides made up of
A
3 fatty acids and glycerol backbone
6
Q
What 2 characteristics are used to classify fatty acids?
A
Chain length
Degree of saturation
7
Q
F/T
Longer chain fatty acids tend to be softer and melt more readily at room temp
A
False
Shorter chains
8
Q
2-4 carbon length is …
6-10 carbon length is …
12 + carbon length is …
A
Short
Medium
Long
9
Q
Degree of saturation refers to…
A
The number of hydrogen atoms a fatty acid chain is holding
10
Q
The more hydrogen atoms attached in a chain the more ______
A
Saturated
11
Q
What impact does the degree of saturation have on melting temp
A
More unsaturated = more liquid at room temp
12
Q
1 point of unsaturation
A
Monounsaturated fatty acid
13
Q
2+ points of unsaturation
A
Polyunsaturated fatty acid
14
Q
0 points of unsaturation
A
Saturated fatty acid
15
Q
This type of fat is the most saturated
A
Animals fats
16
Q
Most vegetable and fish oils are rich in ____
A
Polyunsaturated fats
17
Q
Found in butter and has 4 carbon atoms, single bonds and it saturated
A
Butyric acid
18
Q
Found in beef and has 18 carbon atoms, single bonds and is saturated
A
Stearic acid
19
Q
Found in palm oil and cocoa butter, has 16 atoms, single bonds and is saturated
A
Palmitic acid
20
Q
Found in olive oil and canola oil, 18 carbon atoms, one double bond and is unsaturated (monosaturated )
A
Oleic acic
21
Q
18 carbon atoms and 2 double bonds. Found in most foods esp oilseed (canola and soybean)
Polyunsaturated
A
Linoleic acid
22
Q
T/F linoleic and linolenic acid are essential fatty acid
A
True
23
Q
Unsaturated fatty acids can be found in both cis and trans for dependent on _____
A
Dependant in their structure at double bond
24
Q
Cis form of fatty acid
Melting point?
A
Hydrogen atoms on same side as double bond
Lower
25
Trans form of fatty acid
Melting point?
Hydrogen atom on opposite side of double bond
Higher
26
How do trans fatty acids occur in our diet?
Can be naturally occurring in meat, poultry, processed milk but majority are formed during hydrogenation
27
a process where hydrogen is added to unsaturated fatty acids to make it saturated
hydrogenation
28
T/F during hydrogenation, the hydrogen attaches at the double bond
T
29
What effect does hydrogenation have on the product?
makes the fatty acid more solid @ room temp and increases shelf life
30
T/F points of unsaturation are less vulnerable to oxidation making them go rancid
F
| more vulnerable
31
Which is more resistant to oxidation...
| hydrogenated fats or unhydrogenated fats
hydrogenated fats
32
using an example, how does hydrogenation affect the vitamins?
decreases the activity of vitamin K
33
what fatty acids change shape when hydrogenated
trans fatty acids
34
type of lipid with 2 fatty acids and 1 phosphorus molecule
phospholipid
35
what molecule makes the phospholipid soluble in water? what role does it have?
phosphorus
keeps fats dispersed in water (an emulsifier)
36
what is lecithin and where is it found?
a phospholipid and its found in egg yolk
37
type of lipid with large molecules consisting of interconnecting rings of carbon atoms with side chains of carbon hydrogen and oxygen
sterols
38
list an example of a sterol
cholesterol
39
____ serves as the raw material for making bile.
Important for fat digestion
cholesterol
40
T/F cholesterol is essential bc it cannot be produced by the body
F - can be produced
41
What do sterol do plants manufacture
phytosterols
42
A process to produce salad oils that do not crystallize at fridge temps
winterization of fats
43
describe the process of winterization
lowering the temp of oil to a point where the triglycerides with high melting points crystallize. then oil is filtered to remove the crystals and the remaining has a lower melting point and doesn't crystalize
44
The chemical spoilage that commonly occurs with fats and fatty foods
rancidity
45
fats and oils exposed to __, ___, and ___ are more likely to become rancid
heat
oxygen
light
46
what foods go rancid easily
nuts
wheat germ
whole wheat flour
47
what are the two types of rancidity
1. oxidative rancidity
| 2. hydrolytic rancidity
48
what type of rancidity occurs within unsaturated fatty acid portions.
involves the addition of oxygen to carbon atoms and results in a formation of hydroperocide
oxidative rancidity
49
what can be used to help prevent/slow down oxidative damage?
antioxidants (BHT)
50
what type of rancidity occurs bc of the breaking of chemical bonds due to the addition of water and enzyme activity.
Resulting in the production of glycerol and free short chain fatty acid
hydrolytic rancidity
51
what acts as a catalyst for hydrolytic rancidity
heat
52
what is an ingredient that replaces some or all of the functions of fat and may or may not provide energy
fat replacer
53
T/F Artificial fats are digestible
F they are either totally or partially resistant to digestion
54
what needs to be proven to FDA to gain consent for a fat replacer
little energy is contributed
non-toxic
doesn't build up in body tissues
doesn't rob the body of essential nutrients
55
what are the only 2 essential fatty acids
linoleum acid and linolenic acid
56
what do essential EFA's do in the body
make eicosanoids which are biologically active compounds that regulate body functions
57
what is an omega-6 fatty acid
example?
RRI recommendation?
sources?
double carbon bond 6 carbons from the end
linoleum acid
recommendation 5-10% energy
vegetable oils, seeds, nuts, whole grain products
58
what is an omega-3 fatty acid
example?
RRI recommendation?
sources?
double carbon bond 3 carbons from the end
linolenic acid
recommendation 0.6-1.2%
flaxseed, canola oil, fish
59
research has shown that a higher intact of _____ can often improve the health of our heart
omega-3
60
what are 3 main types of omega 3 fatty acids?
ALA - plant sources
EPA - fish sources
DHA - fish sources
61
the low incidence of cardiovascular disease in Inuit populations has been attributed to...
higher omega 3: omega 6
| based principally on fish products
62
T/F supplements have sufficient levels of important nutrients from fish
F - lack proteins and minerals
63
T/F fish oil supplements are sufficient
F - may be made form skin and livers of fish, increasing the risk of contamination
64
how is conjugated linoleum acid different from linoleum acid?
CLA has two double bonds separated by one single bond
LA has two double bonds separated by two single bonds
65
CLA is an essential fatty acid found mostly in ____
animal products such as milk and meat.
| ruminants and other animals that chew the cud contain more CLA than non-ruminants
66
compounds made up of carbon, hydrogen, oxygen and nitrogen, arranged in strands of amino acids
Proteins
67
the building blocks of proteins
amino acids
68
T/F all amino acids have a different chemical backgroun
F - all made up of 1 carbon atom and an amino group and an acid group
69
what makes amino acids different?
side chain
70
2 amino acids =
dipeptide
71
3 amino acids =
tripeptide
72
>3 amino acids =
polypeptide
73
linear sequence of amino acids
Primary structure
74
repeating pattern of linear amino acids
Secondary structure
75
three dimensional shape where coils fold back on themselves
Tertiary structure
76
globular proteins combined with each other, complex structure
Quaternary structure
77
T/F proteins from animal sources are of higher quality than plant based proteins
T
78
Protein quality is influenced by ______ and _____
digestibility of the protein
amino acid composition
79
rank the following proteins based on the digestibility of their amino acids
legumes
grain/plant proteins
animal
80
a diet short in any essential amino acids ___ protein synthesis
limits
81
list 4 functional properties of proteins
1. protein hydration
2. protein-surface properties
3. flavour binding
4. denaturation and coagulation
82
describe how hydration is a function of proteins
its water binding capacity is related to the amino acid composition.
The more charged the AA, the greater the hydration capacity
83
what is a food system function of protein hydration
- sausages, cakes breads
| - soups, gelatin desserts, dairy products
84
describe how protein-surface properties is functional
proteins are amphiphilic (exhibit both hydrophobic and hydrophilic characteristics, helping to stabilizing emulsions)
involved in the production of food foams
85
what is a food system function of protein-surface properties
- salad dressings, bologna, sausages, ice cream, soups, cheese and sauces
- sponge cakes, whipped toppings, beer froth and ice cream
86
describe the flavour binding properties of proteins
Proteins bind to flavour molecules
| They can also be used to enhance the flavour of processed food
87
what is a food system function of flavour binding properties of proteins
simulated meats (textured soy protein, tofu)
88
describe the denaturation and coagulation properties of proteins
Denaturation changes the original properties of the protein. In most cases, denatured proteins are less soluble. If it is an enzyme, functional ability will be lost
89
what is a food system function of denaturation/coagulation properties of proteins
egg white coagulation when heated
90
what is the term used to describe a browning reaction that occurs when some fruits/veggies are exposed to oxygen
enzymatic browning
91
how can enzymatic browning be blocked?
denaturing the enzyme using heat or by excluding oxygen by covering the surface of the food or by adding ascorbic acid (vitamin C).
92
list 2 types of non enzymatic browning
caramelization
| maillard reaction
93
A series of chemical reactions occur when sugars are heated to temperatures greater than their melting point.
Caramelization
94
Reaction between the carbonyl group (CO) of carbohydrates and amine group (NH2) of an amino acid or protein at high temperatures.
Maillard reaction
95
what are the major components of meat
water
fat
proteins
~some vitamins and minerals
96
what makes meat susceptible to spoilage? how can this be reduced?
high water content and neutral ph
curing (adding salt) or drying
97
why is fish flesh highly perishable?
high levels of unsaturated fatty acids that can be readily oxidized
98
what in the near perfect food and is an important source of high quality protein, minerals, B vitamins, an energy
Milk
99
milk is composed of what two protein fractions
casein (80%)
| whey (20%)
100
list varieties of milk
```
cultured (fermented)
evaporated
sweetened condensed
ultrahigh temp
skim milk powder
```
101
Type of milk
Bacterial cultures are added to ferment the lactose into lactic acid. This increased acidity results in a thickened consistency. Examples include yogurt, sour cream, buttermilk and kefir.
Cultured (fermented)
102
a canned product, where over half of the water content (~60%) is evaporated out of the milk prior to canning. In Canada, evaporated milk is fortified with Vitamins D and C.
Evaporated
103
a canned product where approximately half of the water content is evaporated out of the milk prior to canning and to which a high percentage of sugar is added.
Sweetened condensed
104
the milk is heated for approximately 2-6 seconds at 300oF to remove all viable microorganisms, i.e., the product is sterile.
Ultra high temp
105
The water content of the milk is removed, first through the use of a vacuum and then by spray drying (see unit 2 for more information drying methods). This form of milk can be used in baked goods and can be added to water to reconstitute fluid milk.
Skim milk powder
106
list the functional characteristics of eggs
Emulsification
Foaming
Coagulation
107
organic nutrients that do not contribute energy. They facilitate the release of energy from carbohydrate, fat and protein.
vitamins
108
Vitamins are divided into what 2 categories
fat-soluble
| water-soluble
109
vitamins A, D, E and K are in what category?
fat-soluble
110
vitamin C and the 8 B vitamins are in what category?
water-soluble
111
T/F vitamins still function even if they aren't intact
F
112
In order to preserve vitamins how should they be cooked
short times at moderate temperates with small amounts of water
113
process in which nutrients are added back into foods
enrichment
114
example of enrichment
vitamin D is added back into milk
115
energy role of minerals
act as co-factors in energy-yielding reactions
116
how many minerals are currently known to be essential in human nutrition?
16
117
what two groups are essential minerals broken into?
major minerals
| trace minerals
118
T/F
minerals are heat stable and can impact the chemical and physical properties of foods
