Chapter 5 Flashcards
1
Q
The Structures of Sugars: Composed of ___, ____, and ____.
A
carbon, hydrogen and oxygen
2
Q
Simple sugars:
- ______
- _____
A
Monosaccharides
Disaccharides
3
Q
Sugar Alcohols:
- Sugars with ____ of one corner of their molecule.
- Cause ___ ___ in ___ ___ levels.
- Don’t participate in ____ reactions- lacking ___ ___.
A
modification corner molecule slow rise blood insulin chemical aldehyde group
4
Q
Food Lipids: Fat and Oils
- The predominate chemical structure of lipids is the ____.
- Glycerol is a __-carbon molecule containing __ -___ (___) groups.
-Fatty acids are chains of ____ with a ___ at one end and a ___ at the other end.
A
triglyceride 3 3 -OH (alcohol) carbon carboxyl methyl
5
Q
Saturated and Unsaturated Fats:
- ____– does not contain any C=C.
- ______– have one or more C=C.
A
Saturated
unsaturated
6
Q
The omega naming system names fatty acids by where the __ ___ bond occurs counting from the ___ group ____.
A
first
double
methyl
backward
7
Q
The pattern of the double bonds is also important because it determines ___ ___.
When the double bonds occur between every other carbon it is referred to as ____ double bonds.
A
chemical reactivity
conjugated
8
Q
When a carbon without a double bond occurs between two sets of double bonds it is called ____.
More ____ and more ____.
A
interrupted
typical
reactive
9
Q
Cis and Trans Fats:
- Refers to ___ ___ around the double bond of unsaturated ___.
- When the hydrogen are on the same side it is ___.
- When the hydrogen are on opposite sides it is ___.
A
geometric configuration
FA
cis
trans
10
Q
___ is more common in nature, but ___ configuration occurs when vegetable oil is hydrogenated.
A
Cis
trans
11
Q
___ ___- The temperature where a solid is converted to a liquid.
A
Melting Point
12
Q
Lipids that are ___ at room temperature are referred to as fats and they possess ____ structure.
- The composition of the fat affects its __ ___.
- The more similar the triglycerides in a given fat the ____ the melting range.
- ___ chain fatty acids have higher melting points than ____ chain, ____ higher than ___, ___ higher than ___.
A
solid crystalline melting point narrower Longer shorter saturated unsaturated trans cis
13
Q
**___ ____: Characteristic temperature at which fats begin to break down.
- Most fats begin to decompose ___ their boiling point.
- May spontaneously ___ on the stove if their fumes come in contact with flame.
- Depends on initial __ __ ___ content.
A
Smoke Point
before
ignite
free fatty acid
14
Q
Flavor Compounds:
- Fats are highly important to ___, both good and bad flavors.
- _____ Oils
- ___ ___ products
A
flavor
Essential
Lipid degradation
15
Q
Polar Lipids:
-Represented primarily by ____, these lipids have both ___ and ___ regions (___).
A
phospholipids
polar
nonpolar
amphiphilic
16
Q
Pigments: Many of the pigments that provide color to plants and animals are __ ___.
A
fat soluble
17
Q
Waxes:
- Waxes are ___ melting point lipids composed of a long chain __ ___ and a long chain ___ ___, esterified to each other.
- They primarily occur in the ___ layer of ___ and provide ___.
A
high fatty acid fatty alcohol outer plants protection
18
Q
_____ – splits lipids into higher and lower melting point component parts.
-Can produce a good __ ___ and plastic fat for shortening from same ___ material.
A
Fractionation
frying oil
starting
19
Q
_____ – the forced addition of hydrogen to unsaturated lipids.
-This will raise the ___ ___ and increase ____, but produces ___ ___ ___, which may have health disadvantages.
A
Hydrogenation
melting point
stability
trans fatty acids
20
Q
_____ – a reaction requiring heat plus the addition of water molecules to separate fatty acids from glycerol.
- Produces an __ ___ referred to as ___ ___, which is caused by the release of short chain fatty acids.
- When all three fatty acids are lost during heating, the glycerol molecule can be further degraded to ___, which is responsible for the __ ___ of oils that are at their ___ point.
A
Hydrolysis off flavor hydrolytic rancidity acrolein noxious aroma smoke
21
Q
- _______: This is the rearrangement of fatty acids on the glycerol molecule to create less homogenous triglycerides molecules.
- The primary function of interesterification is to cause __ ___ such as lard to have a ___ texture.
A
Interesterification
plastic fats
smoother
22
Q
Oxidation:
-Oxygen reacts at the double bonds of unsaturated fatty acids and causes the production of __ __ compounds that are responsible for “___” odors.
Unsaturated FA react with oxygen to produce ____ and eventually the degradation of the ___ to ___ compounds (__, ___, __, ___).
A
small organic "rancid" hydroperoxides peroxide volatile ketones, aldehydes, alcohols, acids
23
Q
Oxidation:
- The reaction sequence can be caused by __, __, __, ___, etc.
- ____ can prevent the reaction by donating hydrogen which basically terminates the reaction.
A
heat, light, metals, oxygen
Antioxidants
24
Q
______ - Primarily occurs in heated oils where fatty acids that are cleaved from the glycerol molecules link together to produce polymers.
-Contribute to the ____ of overheated oil and the ____ of foods cooked in overheated oils.
A
Polymerization
smoking
darkening
25
____ – also called “creaming the fat” when baking cakes.
- This step incorporates ___ through agitation of a batter which is held in place by the ___ molecule arrangement of the fat.
- Ultimately responsible for the ___, or ___ of many baked products.
```
Aeration
air
crystal
crumb
texture
```
26
_____– all food fats contain very small crystals of fat which are composed of the fat’s triglycerides.
Crystallization
27
Because of differences in the fatty acids that make up the triglycerides, different ____ arrangements (_____) are possible.
- Include the classifications __, __, __-__,
- __-__ (___ __) is the most desirable from a functionality standpoint because they provide a smooth texture.
- __ ___ (__) coarser.
```
crystalline
polymorphism
α, β, β-prime
B-prime (Beta prime)
B crystals (Beta)
```
28
Crystallization: More ____ triglycerides result in __ ___.
- Fats are interesterified to reduce the ____ and produce _-____ crystals.
- Also, the more homogeneous the more ____ the melting range.
```
homogeneous
B crystals
homogeneity
B-prime
narrow
```
29
Emulsification– ____ are an important component of all food emulsions.
Ex: Cake Batter – __ in ___ emulsion
lipids
| Oil in water
30
Flavor – ____ are believed to have the greatest impact on flavor.
-Their contribution to flavor is due to their inherent ____ properties.
lipids
| flavor
31
Lipids:
Also carry flavor compounds that are lipid soluble such as ____.
-Terpenoids are responsible for __ ___, among many other flavors, which are contained in what is referred to as ___ __.
terpenoids
citrus flavor
essential oils
32
Heat transfer:
| ___ can be heated to higher temperature than ___.
Lipids
| water
33
____: Lipids provide a smooth, creamy sensation during the mastication of food.
-Difficult to ___.
Mouthfeel
| replace
34
______- Refers to the physical property of a fat which describes its softness at room temperature.
-Plastic fat will ___ when spread but __ its __ __.
Plasticity
deform
hold
new shape
35
Plasticity:
- This is due to the ____ nature of ___ lipids.
- ____ crystals have a smoother texture, which can be achieved by proper ____.
-Fats composed mainly of β crystals are less __ and more ___ to the touch.
```
crystalline
solid
β-prime
tempering
plastic
grainy
```
36
______: Because of the lubrication properties of lipids, they also promote _____ of foods that contain them.
- Meat that has higher fat content (___) is more ___ than meat that has __ ___ __.
- In baked goods, ___ interferes with ___ formation.
```
Tenderization
tenderization
marbling
tender
less intramuscular fat
lipid
gluten
```
37
Food Proteins:
- Proteins are polymers of __ __.
- Called ____ because the bond between __ __ is the ___ bond.
-Connects the ____ group of one ___ acid to the ___ acid group of another ___ acid.
```
amino acids
polypeptides
amino acids
peptide
amino
amino
carboxylic
amino
```
38
Amino acids all have an ___ group and a ____ group along with a ___ group.
-Functional group dictates classification as __, ___, ___, ___, or ____ containing amino acids.
amino
carboxylic
functional
neutral, basic, acidic, aromatic or sulfur
39
Proteins exist as either:
- ______: Contain only amino acids
- ______: Combined with other nonprotein substances.
Nonconjugated
| conjugated
40
```
Conjugated:
Examples: ____: ___, e.g. __ ___
Lipid:
Metals: metalloproteins, e.g. hemoglobin
Phosphorus: phosphoproteins,
```
carbs, glycoproteins
| egg white
41
```
There are __ levels of protein structure:
1.
2.
3.
4.
```
```
4
primary
secondary
tertiary
quaternary
```
42
_____ is the linear arrangement of amino acids.
Example: ____ (shorthand for primary structure)
Primary
| N-C-C-N-C-C
43
_____ is the structural arrangement of the amino acids such as __-__, __-___ sheet.
Secondary
alpha-helix
beta-pleated
44
_____ is the overall three dimensional structure.
tertiary
45
_____ is the arrangement of more than one peptide chain within a single protein molecule.
Quaternary
46
_____ – preventing a pH change by undergoing an ionization reaction.
_____ – can behave as both acids and bases.
- ___ groups can act as acids.
- ___ groups can act as bases .
Buffering
Amphoteric
Carboxyl
amino
47
_____ can serve as buffers (maintain pH) because of this and can be either ___ or ____ depending on the pH of the food.
Proteins
acidic
basic
48
_______- the loss of three dimensional structure without breaking the primary structure.
- When proteins denature they lose ____ properties.
- Denaturation occurs due to __, ___ ___.
- __ __ __ may cause the protein to coagulate, which is more ___ than mere denaturation.
```
Denaturation
functional
heat, acid, agitation
Excessive energy input
severe
```
49
Enzymes – all enzymes are ____.
Many enzymes impact ___ ___, both naturally occurring & industrial enzymes that are purposefully used in food processing.
Natural enzymes that influence food quality include ____ in meat and ____ in fruits.
-Enzyme activity is affected by ____ (optimum is generally between __-__degreesC), __ (optimum generally between __-__) and __ __.
```
proteins
food quality
proteases
phenoloxidases
temperature
30-40
ph
water activity
```
50
Emulsification – proteins can stabilize emusions by acting at the __-__ interface.
oil-water
51
Fat Reduction – proteins are often used as __ __.
fat replacers
52
Monosaccharides:
-Are the basic ___ ___ around which ___ carbohydrate units are built.
-Nomenclature is based on the number of ___.
-____ – 3 carbons.
-____ – 5 carbons.
-___ – 6 carbons.
__, ___, ___ – C6H12O6
```
building blocks
larger
carbons
trioses
pentoses
hexoses
glucose, fructose, galactose
```
53
Monosaccharides:
-Structural features, which are dependent on the location of ____ groups, have an influence on ____ properties.
-Glucose has a __ membered ring (___)
Fructose has a __ membered ring (___)
-This difference is partially responsible for the fact that fructose is ___ and more ___ than glucose.
```
functional
functional
6
aldose
5
ketose
sweeter
soluble
```
54
Disaccharides:
-___ monosaccharides bonded together by a ___ bond.
two
| glycosidic
55
The three most common disaccharides in food are:
1. _____ (____ + ____) - common table sugar
2. ____ (___ + ___) - milk sugar
3. _____ (___ + ____) - common breakdown product from starch.
```
sucrose
glucose
fructose
lactose
glucose galactose
maltose
glucose
glucose
```
56
Two important functional groups of Sugars:
1. ___ (-___) group– important for solubility & sweetness.
2. ___ (___) group– important for reducing activity and Maillard browning for color/flavor development.
Alcohol -OH
| Carbonyl (-C=O)
57
Sugar functional groups:
These functional groups are either a ___ (on the ___ of the molecule) or an ____ (on the ___ of the molecule).
ketone
interior
aldehyde
end
58
Reducing sugars- contain a ____ group (___ or _____).
-All ______ are reducing sugars.
carbonyl
(aldehyde or ketone)
monosaccharides
59
There are two important browning reactions that occur in sugar:
1. _____ reactions
2. _______
Both are categorized as ______.
Maillard
Caramelization
nonenzymatic
60
____ _____ – a complex series of reactions that requires a reducing sugar and amino acids in foods.
Maillard reaction
61
____ ____ – the browning of foods as a result of the Maillard reaction.
-Intermediate products: _____, which tend to have pleasant aromas and flavor.
- End products: brown pigments called ____.
- _____ and result in ____ of food.
```
Maillard browning
pyrazines
melanoidins
Irreversible
darkening
```
62
The Maillard reaction is responsible for both ___ and ____ quality attributes, depending on the product.
positive and negative
63
The Maillard reaction takes place at relatively __ temperatures and can be accelerated by ___ molecular weight sugars, low __ __ (<15%) and in the pH range of __-__.
low
lower
moisture content
5-8
64
Caramelization – takes place at ___ temperature (200 C)
- Due to the _____ of the sugar molecule.
- ___ ___ refers to a brown coloring used in the food industry.
- Caramel refers to sauces or candies made from carbohydrates that have been allowed to ____.
high
dehydration
Caramel coloring
caramelize
65
Crystallization:
- ___ ___ can exist as syrups or the crystallized state.
- Crystallization– implies organized __-_ arrays of unit cells into solid form.
- In candy manufacture, control of the ____ process is highly critical to the ultimate quality of the candy.
Simple sugars
3-D
crystallization
66
____– a substance that has an affinity for moisture, also referred to as hygroscopic substances.
-This is ultimately related to their ability to form ____ bonds with ____.
Humectant
hydrogen
water
67
Inversion refers to the process where ___ is hydrolyzed to ___ and ____, which are then called ___ ___.
-Inversion can be induced by __, ___, or a special enzymes called ___.
```
sucrose
fructose
glucose
invert sugars
heat, acid
invertase
```
68
Sugars undergo __ ___ reactions that promote important functional characteristics
Oxidation of the aldehyde group in sugars causes a loss of ___ and converts it to an ___.
Reduction of the ___ group of reducing sugars causes the formation of __ ___, which are moderately sweet.
Ex: ___ and ___
```
oxidation reduction
sweetness
acid
carbonyl
sugar alcohols
mannitol and sorbitol
```
69
Sweetness is probably the most notable functional characteristic of __ ___, although ___ varies between different sugars.
-___ is usually used as the reference with other sugars.
____>___>____>___>___>___
```
simple sugars
sweetness
Sucrose
Fructose>sucrose>
glucose>maltose>
galactose>lactose
```
70
Effect on texture through their interaction with ___.
-Sugar can provide ___, ____ (e.g. in baked goods) and can influence other texture promoting compounds such as __.
water
bulk
tenderization
starch
71
Polysaccharides:
Also called ___ ___ because of their large size.
-Polymers of monosaccharides and classified as either:
_____ (3-10 units)
_____ (>10 units)
complex carbohydrates
Oligosaccharides
polysaccharides
72
Oligosaccharides
Ex: ____ and ____.
- Present in ___ ___.
- Not digested in the __ ___ but are fermented by microorganisms in the ___ ___.
```
raffinose
stachyose
dried beans
small intestine
large intestine
```
73
Polysaccharides are much more ____ in foods than oligosaccharides and are commonly used as ___ to food for specific aspects of functionality.
abundant
| additives
74
Beta-glucans:
-___ of glucose.
-Considered a ___ __ ____.
-Found primarily in __, __, and ___
-Have been found to lower ___ __(FDA allows this claim).
-Used as a __ __ in many different manufactured food products.
___ – used in baked goods, fillings and frostings, frozen desserts, salad dressings, etc.
```
Polymers
soluble dietary fiber
oats, barley, and yeast
serum cholesterol
fat replacer
Oatrim
```
75
Cellulose:
-Most ___ of all carbohydrate polymers.
-Structural component of all __ __.
-The main source of __ __ __.
-Microparticulate form of cellulose:
Used as a __ __ and to increase dietary fiber in foods.
abundant
plant cells
insoluble dietary fiber
bulking agent
76
Dextrins & Maltodextrins:
- Both are derived from the breakdown of ___.
- Have ___ glucose chains than starch but are still considered polysaccharides.
-The term dextrin is generally applied to any __ molecule that has undergone ___, usually by __.
```
starch
shorter
starch
degradation
heat
```
77
_____ are more specifically related to commercially generated products, usually from cornstarch.
-Used in sauces, baked goods, processed meats as fat replacer and bulking agent.
Maltodextrins
78
Fructooligosaccharides:
- Polymers containing primarily ___, usually in association with ___.
- Found in a variety of ___ including garlic, onions, bananas, etc.
-Considered ____ because they are not broken down in the __ __ and make it to the large intestine where they nourish good bacteria (___).
```
fructose
sucrose
plants
prebiotics
small intestine
probiotics
```
79
Inulin: Dietary Fiber
- ___ is a type of fructooligosaccharide found in onions, asparagus and especially chicory root.
- Serves as a ___ to stimulate the growth of good bacteria.
- Can be used to adjust ___ attributes.
Inulin
prebiotic
textural
80
Pectic Substances:
- ___ molecular weight polysaccharides found in plant cell walls, primarily for ___.
- Composed of ____ acid units some of which are methylated, which determines functionality.
High
support
galacturonic
81
Pectic Substances:
-___ chemically distinct substances:
1. ____ – nonmethylated and found in immature fruit
2. __ __ – methylated and produced during ripening
3. __ ___– demethylated derivative of pectinic acid and associated with overripe fruit
three
Protopectin
pectinic acid
pectic acid
82
Pectic substances:
Degree of ____ (_____) deterimines functionality. High methoxyl (HM) pectin have > __% methylation, whereas low methoxyl (LM) pectin generally has < __% methylation.
esterification
methoxylation
50
30
83
Pectic Substances:
-Pectin ____
Pectins are able to form ___ ___ (sols and gels).
Gelation
| colloidal dispersions
84
To convert a HM pectin sol to a gel it is necessary to reduce the association of pectin with ___ by incorporating ___ and reduce the __ __ between pectin molecules.
water
| sugar repulsive forces
85
LM pectin can be converted into a gel without ___ by adding ___ ___ such as calcium.
Thus, LM pectin is used in the manufacture of __ __ ___.
sugar
divalent cations
sugar free jelly
86
Starch is the predominate source of __ __ in the world’s food supply.
It is a ___ of glucose molecules, found in two forms:
____– a straight chain.
_____ – numerous branches.
dietary energy
polymer
amylose
amylopectin
87
Starch:
Packaged in the plant as __ __.
Starches that are high in ___ can form gels.
Starches high in amylopectin can’t but do increase in ___.
\
starch granules
amylose
viscosity
88
Starch is often modified to change its ____.
| An example of a modified starch is ___ ___, which is used in instant pudding and pie filling.
functionality
| pregelatinized starch
89
Starch Gelatinization:
Starch is not soluble in __ water, but if __ and ___ it undergoes a conversion that is referred to as ____
During gelatinization, the heated starch granules absorb ___ and ___.
- ___ reaction.
- Increased ___.
```
cold
agitated and heated
gelatinization
water and swell
Irreversible
viscosity
```
90
Starch Pasting and Gel Formation:
__ ___ – a starch/water system the has both thick liquid and solid-like properties.
____ can be thought of as a continuation of gelatinization where the thickening of the slurry occurs.
Starch paste
| Pasting
91
Starch Pasting and Gel Formation:
In a paste, majority of starch granules have ___, producing __ and ___ granules.
____ – the formation of a gel from a cooled paste.
____ ___ – a thick starch/water mixture that has properties of a solid.
gelatinized
swollen and disrupted
Gelation
Starch gel
92
Starch Retrogradation:
_____ is the contraction of starch gels due to interactions between amylose molecules.
As the gel tightens it can __ water, which is referred to as ____.
Retrogradation
lose
syneresis
93
Vegetable Gums:
Vegetable gums are a broad category of ___ ___ that contain a variety of sugars including __ and ___.
complex polysaccharides
| pentoses and hexoses
94
Gums are derived from a variety of sources including __ __ (__), seaweed (___), and microorganisms (___).
plant seeds (guar)
carageenans
xanthan
95
_____– proteins are good foaming agents because they can reduce interfacial tension and allow air to be incorporated into liquids.
Egg white meringues.
Foaming
96
____– some proteins can form three dimensional networks that allow incorporation of water and form gels.
Collagen that is used in Jell-O™ products.
Gelation
97
______– functionality is often dictated by solubility, which is affected by pH, temperature, etc.
Certain applications such as edible film manufacture require highly __ ___.
Solubility
| soluble proteins
98
___-____ ___– This is the ability for a protein to bind water and is due to its hydrophilic components.
Water holding capacity is lowest, which means ___ is lowest at the ____ (__), where the charge on the molecule is neutral, which reduces the water protein interactions and maximizes the protein-protein interactions (causes protein to precipitate out of solution).
Water-holding Capacity
solubility
isoelectric pH (pi)
