Domain 1 - Food Science, Nutrient Composition of Foods Flashcards
1
Q
what is the water content of fruits and vegetables
A
75-93%
2
Q
what is the cause of crispness (state of turgor) of fruits and vegetables
A
osmotic pressure of water filled vacuoles
3
Q
what is the limiting amino acid in soybeans
A
methionine
4
Q
what is protopectin converted to
A
pectin (indicates ripe fruit)
5
Q
what is pectin converted to
A
pectic acid (overripe fruit)
6
Q
what accelerates ripening of fruits during storage?
A
ethylene gas
7
Q
what temp should frozen fruit be stored at?
A
0 degrees F
8
Q
what fruits ripen best at room temp?
A
avocado, banana, pear, tomato
9
Q
how can you delay aging in apples?
A
store in a controlled atmosphere (reduced oxygen)
10
Q
why do fruits low in vitamin C darken rapidly when cut? how can you prevent this?
A
enzymatic action - to prevent dip in citrus juice, add sugar before freezing, heat to boiling
11
Q
what does a Brix hydrometer measure
A
% sucrose by weight
12
Q
describe chlorophyll…… more like borophyll
A
green, Insoluble in water
olive green in acid (pheophytin)
bright green in alkaline (chlorophyllin)
13
Q
describe carotenoids
A
yellow/orange, insoluble in water
little color effect in acid or alkaline
lycopene - red in tomato/watermelon, overtone in aprictos (antioxidant/phytochemical)
14
Q
what are 2 types of flavinoids
A
anthocyanins, anthoxanthis (flavones) - they are both soluble in water
15
Q
describe anthocyanins
A
red, blue, purple
Soluble in water
bright red in acid
bluish tone in alkaline
16
Q
describe anthoxanthins
A
white
soluble in water
colorless in acid
yellow in alkaline
17
Q
what provides flavor in peas and corn
A
sugars
18
Q
what provides flavor in onion and cabbage
A
sulfur
19
Q
what is glutamic acid used in
A
MSG (form of salt)
20
Q
what provides flavor is fruits (3 things)
A
acids, sugars, aromatic compounds (such as tannins - cause astringent feeling in mouth, underripe banana)
21
Q
describe Grade A canned fruits and vegetables
A
fancy - desserts, salads
22
Q
describe Grade B canned fruits and vegetables
A
choice - processed
23
Q
describe Grade C canned fruits and vegetables
A
standard - puddings, pies
24
Q
what are the grades of fresh produce
A
fancy, extra #1, extra #2, combination, #2
25
what is the green color under potatoes skin due too
chlorophyll that develops when potato is exposed to light during storage
26
potatoes contain what compound which is a natural toxicant
solanine
27
what are benefits of microwaving vegetables
less time, retain color, vitamins, not a large difference in eating quality
28
describe a #10 can (most important!)
6 cans per case, 6lb 9oz, 13 cups in each can, 20-25 servings
29
describe a #3 can
12 cans per case, 46 oz, 5 3/4 cups, serves 12-15
30
describe a #2 1/2 can
24 cans per case, 1lb 13 oz, 3.5 cups, serves 6-8
31
describe a #2 can
24 cans per case, 1lb 4 oz, 2.5 cups, serves 4-6
32
describe a #300 can
24 cans per case, 14-16 oz, 1 3/4 cups, serves 3-4
33
what is the structural part of the tendon that surrounds muscle, and what happens to it in heat
collagen - in heat it is hydrolyzed to gelatin and becomes tender
34
what happens to elastin in heat
little change, it is resistant to heat
35
in potatoes, starch changes to what during storage
sugar
36
muscle is composed of bundles of fibers called what
myofibrils
37
what holds fibers in bundles
sheet of connective tissue
38
what identifies a cut of meat
shape of bone (round bone - leg, t-bone - back and ribs, etc)
39
what % protein is meat/poultry/fish
16-23%
40
what vitamins/minerals are meat/poultry/fish high in
thiamin, niacin, riboflavin, iron, copper, trace minerals
41
pork is an especially good source of what
thiamin
42
calcium content is higher in what types of fish
canned fish with bones, oysters, shrimp
43
fish has ____ fat and _____ moisture than meat
less, more
44
why is TVP mixed with ground meats
more servings, lower costs
45
soy protein adds ______ due to _____ content
juiciness, water
46
what is the main contributor to meat color
myoglobin
47
myoglobin exposed to oxygen turns front red to what color
brown, and green with further breakdown
48
how does acid (vinegar) and salt increase tenderness
increase water-holding capacity of muscle and lowers pH
49
how should meat be aged and ripened
hold in cold storage for about 10 days
50
change in muscle protein by enzymes increase _____ of muscle
water-holding capacity
51
what may extend storage life of meat
anaerobic (sous vide) packaging - vacuum packed, stored unfrozen at 0 C
52
what is MAP (modified atmosphere packaging)
air in packaging is removed and replaced with gases (carbon dioxide, nitrogen)
53
when is USDA inspection and grading of meat done
at slaughter
54
which act assures the consumer that animals are healthy at slaughter and meat is fit for consumption
Wholesome Meat Act of 1967
55
what are the grades of meat
prime, choice, select, standard
56
what are grades of meat based on
maturity of animal, marbling, color, texture
57
which grade has the least marbling and which has the most
standard has least, prime has most
58
which cuts of meat are most tender
loin (pork chops), backbone
59
which cuts of meat are medium tender
shoulder (chuck)
60
which cuts of meat are least tender
flank, brisket
61
what is the proper temp for a roast
325 F
62
when should a meat thermometer be inserted
before cooking
63
a ____ cooked roast yields less waste
slow
64
what meats have a safe internal temp of 145 F
pork, beef, veal, lamb, steaks, roast, fish
65
what meats have a safe internal temp of 160 F
ground beef, ground veal, ground lamb
66
what meats have a safe internal temp of 165 F
turkey, chicken, duck
67
collagen is hydrolyzed to _____
gelatin
68
why must tough cuts of meat be cooked well done
they have more collagen which needs more time to be softened
69
why do meat surfaces become brown
breakdown of pigments
70
heat _____ globin
denatures
71
when meats are heated, iron is _______
oxidized
72
why are cured meats pink
nitrites
73
what types of cuts should be cooked with dry heat
tender cuts such as backbone, loin, sirloin
74
what are dry heat cooking methods
frying, broiling, roasting
75
what is "carry-over cooking"
after roasting, meat is removed from oven and for about 10 minutes internal meat temp will rise 15-25 F
76
how long should a roast stand before carving
30 minutes
77
what types of cuts should be cooked with moist heat
less tender cuts with more connective tissue, tough cuts (round, chick, brisket)
78
how should a bottom round be cooked
in water for several hours
79
what are moist heat cooking methods
braising, simmering, steaming, stewing
80
_______ enzymes such as _____ tenderizes meat
proteolytic, papain
81
fresh fish with head attached should have ______ red gills, _____ skin
bright, shiny
82
what is surimi
purified and frozen minced fish with a preservative
83
egg yolk is a naturally occurring _______
oil in water emulsion
84
a good quality egg is indicated by what
high proportion of thick white
85
in an egg, what becomes larger with age
air space within the egg
86
what holds an egg yolk in the center
chalazae (yolk anchor)
87
what vitamins/minerals is egg rich in
vitamin A, D, riboflavin
88
what is color of yolk dependent on
amount and type of pigment in a hen's diet
89
what are grades of eggs
AA, A, B
90
grading of eggs is based on what
thickness of white, location and condition of yolk
91
what is candling
passing an egg in front of bright light to view contents, helpful when grading and judging quality
92
what are the sizes of eggs
jumbo, xl, large, medium, small, peewee
93
how long can egg freshness be maintained in cold storage (29-32F)
6 months
94
a fresh egg will _________ in a pan of cold water and has a ______ shell
sink to the bottom, dull and rough
95
at what temperature does protein coagulate
62-70 C
96
what is syneresis
weeping, liquid released from a coagulated product
97
when does syneresis occur
when cooked at too high of a temp or too low of a temp for a long time - leads to tough, watery product
98
what will stiffen an egg white foam
acid - it will tenderize the protein and allow it to extend more easily
sugar will also stabilize egg white foams
99
how are egg white foams compared
measure specific gravity (relative density of a substance in relation to that of water)
weight of given volume / weight of same volume in water
100
egg whites at room temperature whip more quickly and yield a larger volume due to _______ surface tension
lower
101
what helps an egg yolk act as an emulsifier
lecithin
102
what stabilizes the egg yolk emulsion
lipoproteins
103
why do eggs yolks yield stiffer, more stable emulsions than egg whites
they have more protein by weight
104
what can hasten coagulation in egg cooking
vinegar and salt
105
why do egg yolk surfaces turn green when overcooked or cooled to slowly
iron from the yolk and sulfur from the whole egg create ferrous sulfide
106
in dry heat cooking of eggs, what will result from undercooking
excess shrinkage
107
in dry heat cooking of eggs, what will result from overcooking
tougher product
108
the larger the % sag, the ______ tender the gel
more
109
egg substitutes are often ______ in sodium
higher
110
what differences occur when using egg substitutes
color and flavor differences
111
dried eggs are ____ % white, ____ % yolk
70, 30
112
dried eggs can be vacuum packed in what
nitrogen gas
113
what is added to improve foaming ability in bakers special eggs
sucrose
114
if eggs are stored in the fridge for too long, whites become _____, yolks ______, and odors are ______
watery, flatten, absorbed
115
if eggs are stored in the fridge for too long, ______ and ______ is lost
water and carbon dioxide
116
loss of carbon dioxide causes eggs to be more _______
alkaline
117
milk is a good source of what vitamins and minerals
calcium, phosphorus, riboflavin
| Vitamin A, D
118
milk is not a good source of what mineral
iron
119
what is the % composition of milk (water, macronutrients)
87% water, 3.7% fat, 4.9% cho (lactose), 3.5% protein (complete hbv)
120
the protein in milk is ____ % casein
80% (precipitated at ph 4.6, forms soft curd)
121
liquid that drains from curd of clotted milk is known as what
whey
122
how is milk pasteurization done
heat to 145 F for 30 min or 160 F for 15 seconds
123
what is the purpose of pasteurization
destroy pathogenic bacteria
124
name the components of whey (5)
lactose, lactalbumin, lactoglobulin, water soluble vitamins, minerals
125
types of milk
high pressure breaks fat globules to 1/5 regular size; film of protein surrounds each globule; more susceptible to action of lipase, but the pasteurization process destroys lipase
homogenized
126
types of milk
400 USP units added per quart of milk by feeding the cow this vitamin, irradiating the milk, or adding the vitamin
vitamin D milk - must be labeled
127
name the 4 concentrated milks
```
evaporated milk (60% water removed)
sweetened milk (add 15-18% sucrose or glucose)
dried whole milk (26% fat, does not keep well)
dried skim milk (not more than 1.5% fat, keeps well)
```
128
name the 3 fermented milks
cultured buttermilk
sweet acidophilus
kefir
129
2% milk has ______ % fat, low fat milk has _____ % fat, and skim milk has ______ % fat
1.5-2.25%
.5-2%
<0.5%
130
in cultured buttermilk, add ____ ____ bacteria to skimmed or partly skimmed milk
lactic acid bacteria
131
in place of using buttermilk in place of regular milk in a recipe, increase ________
baking soda
132
sweet acidophilus milk (skim milk + sweet acidophilus bacteria) reduces ______
lactose
133
the coagulated product of fermentation of milk sugars by lactic acid bacteria is known as
yogurt
134
when milk is heated, what happens to they whey protein?
it precipitates out on bottom of pan or on surface of milk
135
how do you prevent milk from curdling?
add an acid slowly and agitate
136
in milk, an acid precipitates _______
casein
137
butter is 80% __________ and margarine is 80% ___________ or ____________
milk fat
| vegetable oil or animal fat
138
does butter or margarine turns rancid as it takes up oxygen an releases hydrogen
butter
139
what are the types of cream
```
heavy or thick
medium
whipped cream
light or thin
sour cream
half and half
```
140
which creams have the highest fat content
heavy or thick >36% fat
medium 30-36% fat
whipped cream 35% fat
141
during cheese production, what enzyme is added, which coagulates casein and forms curd
rennet
142
what are the 3 types of cheese
uncured (cottage cheese)
cured (additional whey removed, salt added, ripened)
processed (blend of several natural cheeses)
143
what is the emulsifier added to processed cheese
disodium phosphate- makes cheese better for cooking; fat will not spread out
144
what are the main structural parts of grains and cereals
starchy endosperm rich in protein
outer layer of hull and bran
scutellum within the germ - contains most of thiamin
145
what vitamins and minerals are found in grains and cereals
vitamin E (in germ), thiamin (scutellum), riboflavin, phosphorus
146
grains are ____% starch, ___ % fat found in the germ, and contain ______ proteins
75%, 2%, partially complete
147
what is the inner portion of a wheat kernel called
farina
148
quick-cooking cereals have ________ added
disodium phosphate - makes cereal alkaline so particles swell faster
avoid this on low sodium diets
149
strength of gluten and protein content have a negative or positive relationship
negative - the stronger the gluten, the more protein; the weaker the gluten, the less protein
150
name the 8 different wheat flours
```
graham
bread (hard wheat)
all-purpose (blend of hard and soft wheat)
pastry (soft wheat)
cake (soft wheat)
enriched (with B vits, iron and folic acid)
instant blending
self-rising
```
151
place the following flours in order from strongest gluten and most protein to weakest gluten and least protein: all-purpose, cake, pastry, bread
bread (strong gluten, 11.8% pro)
all-purpose (less gluten, 10.5% pro)
pastry (weaker gluten, 7.9% pro)
cake (least and weakest gluten, more starch, 7.5% pro)
152
what is gluten made from and what does it do
it is made from gliadin and glutenin through process of hydration and mixing
it gives elastic properties, forms framework, holds in leavening agent
153
what is the color of flour due to
carotenoids
154
if an oxidizing agent is added to flour, what is it labeled as
bleached - natural agents cause oxidation and turn flour from creamy yellow to white
155
adding bran increase or decreases volume of end product
decrease - increase flour and liquid to compensate
156
name 3 leavening agents
steam
air
carbon dioxide (from yeast, baking soda, baking powder)
157
how do you incorporate air into baked flour mixtures
beat, sift, fold, cream
158
what does the action of yeast on sugar yield
carbon dioxide and alcohol
159
________ is produced from the action of acid on baking soda
carbon dioxide
| - acids include sour milk, cream of tartar, molasses
160
baking soda + a dry acid + corn starch =
baking powder
161
baking soda provides
carbon dioxide
162
cornstarch keeps contents ____
dry
163
a dry acid reacts with baking soda to release
carbon dioxide
164
a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods - it works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture
baking powder
165
what are 3 types of baking powder
tartrate, phosphate, combination
166
use ____ tsp baking powder per ___ cup flour
1 1/2 tsp baking powder per 1 cup flour
167
old baking powder becomes more alkaline causing loss of _______ in baked goods
thiamin
168
_____ keeps yeast from sticking in baked flour mixtures
salt
169
_____ provides stability, retains leavening agent, distributes shortening by emulsification, introduces air, adds color and flavor in baked flour mixtures
egg
170
____ adds tenderness by coating gluten products particles in baked flour mixtures
fat
171
______ is hydroscopic, it modifies texture by tenderizing, and it softens gluten and prevents gluten development by absorbing some of the water that gluten needs
sugar
172
too much sugar in a flour mixture results in
coarse cells, thick walls, a shiny crust and a crumbly product
173
most of the sugar in honey is ____ and _____
glucose and fructose
174
term used to distribute fat into dry ingredients
cut-in
175
method of mixing used in foams- a down, across, up and across the top motion while rotating bowl
fold
176
_______ are leavened with steam, air, chemical leavening agents
ex: muffins, biscuits, popovers
quick breads
177
2 basic ingredients in quick breads are
egg and flour
178
excess mixing causes what
loss of carbon dioxide, tunnels from top to bottom, tough and heavy product
179
characteristics of a good muffin
round
pebbled top
pymmetrical shape
no long, narrow tunnels
180
method of mixing cake
cream fat with sugar, add egg, add sifted dry ingredients in portions, alternating with portions of milk
181
2 types of cakes
```
shortened cake (layer, pound cake, etc.)
foam cake (angel cake)
```
182
shortened cake uses _____ as leavening agent, while foam cake uses ____ as leavening agent
chemical leavening; air
183
```
shortened cakes:
layer cake uses _____
pound cake uses ____ and _____
rich cakes uses increased ___, ___, ___
gold cake uses egg _____
white cake uses egg _____
yellow cake uses _____ _____
```
```
baking soda
air and steam
fat, sugar, egg
yolks
whites
whole egg
```
184
foam cakes:
angel cake: ___ ___ foam
sponge cake: ____ foam and ____ foam
chiffon cake: ____, ____, ____ and ____
egg white foam
yolk foam and white foam
liquid yolks, egg white foam, baking powder, oil
185
in cake, the more _____ the more time is needed to reach the elevated coagulation temperature of the gluten
sugar
*as sugar increases, the volume of cake increases up to the point where the volume is so great, and the gluten so weak, that the gluten stands snap and the cake falls in the center (gummy, crystalline appearance)
186
yellowing of cake is caused by
alkaline batter (excess baking soda)
187
fallen center of cake may be caused by
excess sugar, excess fat, excess baking powder, inadequate mixing, oven temp too low, open door during early baking
188
tough, dry crumb of cake is caused by
too much flour or egg, too much mixing, too little fat or sugar, over-baking
189
coarse texture in cake is caused by
too much baking powder or sugar, oven temperature to low, inadequate mixing
190
poor volume in cake is caused by
too little baking powder, improper level of sugar or fat
191
cookies are a modified shortened cake, which are higher in ___ and lower in ____ and ____
higher in fat
| lower in sugar and liquid
192
pastries involve ____, ____, ____ and ____
flour, fat, liquid and salt
193
lard and oil are ___% fat, butter is ___% fat
100%; 80%
| *when substituting butter for lard, need to use more
194
how is the tenderness in pie crust enhanced
by using oil, soft fats, or fat cut into very small pieces
195
how is flakiness of a pastry promoted
by leavening fat in coarse particles. Fat in pieces melts and flows, leaving a hole where steam collects and pushes upward against the upper surface of the resulting cell. the cell is locked into that extended position, resulting in a flaky crust
196
```
proportion of liquid to flour parts in the following:
pour batter (ex. waffles)
drop batter (ex. muffins)
soft dough (bread)
stiff dough (ex. pie crust)
```
liquid to flour
1: 1
1: 2
1: 3
1: 4
197
Use high protein bread flour in __________
```
yeast dough
(low protein flour causes crumbly products with poor texture)
```
198
what does yeast do
ferments sugar and releases carbon dioxide
199
which method of preparing dough involves all ingredients being added before dough is allowed to rise
straight dough method
200
which method of preparing dough involves combining liquid with yeast and part of flour and allow this batter (sponge) to ferment for several hours; add sugar, salt, fat, rest of flour; knead
sponge dough method
201
which method of preparing dough:
- reduces processing time
- not as affected by fermentation time and temp
- commercial process that substitutes intense mechanical energy to a large degree for traditional bulk fermentation
continuous bread-making method
202
what is the final rising of the dough (fermentation) called
proofing time
* shortened in sponge method
* use strong flour, high in protein (bread flour)
203
when baking at high altitudes, you may have to decrease amount of ________ and increase amount of _______
baking powder, liquid
204
starch is compose of _____ and _____
amylose and amylopectin molecules
205
______ is responsible for gelation in cooled, cooked pastes
amylose
206
corn, rice and sorghum have only ______
amylopectin
* non-gelling; stable to freezing and thawing
* used in frozen foods
207
place the following starches in order of the effectiveness of thickening ability:
wheat, waxy rice, tapioca, waxy sorghum, potato, waxy corn
potato (best thickener), waxy corn, waxy rice, waxy sorghum, tapioca, wheat
208
wheat _____ is even less effective than pure wheat ______ because of the protein content
flour; starch
209
pastry and cake flour have more starch and less gluten, so they thicken (better or worse)
better
210
________ is the swelling that occurs when starch is heated in water close to the boiling point
gelatinization
| *heat dissociates bonds, water moves in and swells granules
211
during gelatinization, sugar increases ________ and reduces _____ and ______
translucency; viscosity; gel strength
212
what happens if lemon juice (acid) is added to lemon meringue pie before cooking is complete and why
filling will be runny because acid breaks down starch and will give a runny product
213
what occurs in starches with a high proportion of amylose and is undesirable (reduced quality)
retrogradation (recrystallization)
| -gives a gritty texture
214
what white sauce is half fat, half flour made by first melting the fat and adding flour
roux
215
to get a clear, shiny, translucent sauce, use ______ as thickener
cornstarch
216
name 3 crystal inhibitors (in crystallization)
acid (cream of tartar, vinegar)
fat (chocolate, milk)
protein (milk, egg whites, gelation)
217
overrun ice cream is the increase in volume from ______ and ______
freezing and whipping
218
how does fat interfere with crystal formation
it makes crystals small and smooth
| *to make smoother ice cream, increase fat
219
gelatin
___ calories per gram
incomplete protein with no _____, and low ____ and ____
4 kcal/g
no tryptophan
low in methionine and lysine
220
an enzyme in fresh or frozen pineapple the breaks down protein and prevents gelation
bromelain
221
for best flavor, coffee should be brewed at ____ F
185-203 F
| *at high temps, tannin is extracted and coffee is bitter
222
the FDA controls ______
additives (emulsifiers, humectant, stabilizers, anti-caking, nitrates etc.)
223
monoglycerides
diglycerides
lecithin
disodium phosphate
all examples of what
emulsifiers
224
gylcerol monostearate is what
humectant - retains h20
225
propionate is what
preservative; mold inhibitor
226
______ foods provide more benefits than the basic nutritional benefits
functional foods
227
functional food that reduces total and LDL cholesterol; found in fortified margarines
plant sterols and stanol esters
228
functional food that is found in grape juice and red wine; reduces platelet aggregation
resveratrol
229
functional food that is found in tomatoes; may reduce prostate cancer
lycopene
230
biologically active, naturally occurring chemical components in plant foods, act as natural defense for the plant - these are called what
phytochemicals
231
example of a phytochemical; from the cruciferous vegetables; detoxification of carcinogens
thiols
232
the additive influence of foods and constituents which, when eaten, have a beneficial effect on health
food synergy
