Principles Of Dietetics - topic A: food nutrition and supporting sciences Flashcards
(106 cards)
1
Q
Climacteric fruits
A
ripen post-harvest
examples: peach, pear, banana, apple, tomato
2
Q
Non-climacteric fruits
A
best when ripened before harvest
examples: grapes, melon, citrus
3
Q
olive green in acid
A
pheophytin
4
Q
bright green in alkaline
A
chlorophyllin (mushy: hemicellulose broken down)
5
Q
one dozen oranges will yield
A
one quart of juice
6
Q
cooking method - frozen
A
shorter cooking time than fresh because blanching and freezing have made them tender
7
Q
blanching
A
immersion in boiling water for a short time
8
Q
10, #6/CASE
A
13 CUPS
9
Q
canned fruits and vegetable grades USDA
A
grade A - desserts, salads (fancy)
grade B - processed (choice)
grade C - puddings, pies (standard
10
Q
fresh produce grades USDA
A
fancy, extra #1, #1, combination, #2
11
Q
vitamins and minerals in meat, poultry, fish, and meat alternatives
A
thiamin, niacin, riboflavin, iron, copper, trace minerals
12
Q
pork is a good souce of what
A
thiamin
(high heat destroys thiamin)
13
Q
fish paste
A
good source of nondairy calcium
14
Q
pigments - meat - green colors
A
green colors are due to further myoglobin breakdown, oxidation of pigment myoglobin
15
Q
post-mortem changes and aging
A
- change in muscle protein brought about by enzymes which increase the water-holding capacity of the muscle
- acid (vinegar) and salt also increase tenderness by increasing water-holding capacity of muscle
- MAP (modified atmosphere packaging) prevents deterioration by slowing respiration
16
Q
inspection and grading
A
shown with a round purple inspection stamp/sticker “USDA Inspected and Passed”
17
Q
cookery principles and temepratures
A
temp - 325’F for roasting
- high temp increases shrinkage, toughen
- a slow-cooked roast yields less waste
- insert meat thermometer BEFORE cooking
- safe minimum internal temperatures
- 145’F: pork, beef, veal, lamb, steaks, roast, fish
- 160’F ground beef, ground veal, ground lamb
- 165’F turkey, chicken, duck
18
Q
vacuum wrapped meats
A
cured meats are pink from nitrites (inhibit botulism)
19
Q
tempering meat
A
allows it to cook more evenly
- Letting meat sit out at room temperature before cooking it
20
Q
method of cooking determined by cut of meat - dry heat
A
no water involved, for tender cuts near backbone (loin, sirloin)
21
Q
method of cooking determined by cut of meat - frying
A
heat the fat before it smokes
- desirable property of fat used in frying is a high smoke point > 400’F
- highest = safflower 513’F
- lowest = butter 350’F
22
Q
rancidity in an unsaturated fatty acid
A
involves the uptake of oxygen in an unsaturated fatty acid
- healthiest plant oils are all highly unsaturated (olive oil has more MUS; less susceptible to rancidity than soybean oil which has more PUS)
- greater # of double bonds, greater risk of rancidity
23
Q
fish cookery- smell
A
fresh fish should not smell fishy
24
Q
egg yolk
A
is a naturally occurring oil in water emulsion and has more protein by weight
25
egg freshness
old eggs float, fresh eggs sink
26
eggs - preparation and processing - syneresis
syneresis (weeping) - liquid released from a coagulated product
- occurs when cooked at too high a temperature, or too low a temperature for too long a time; creates a tough watery product
27
egg substitutes
- lower in fat, kcal, cholesterol; often higher in sodium than fresh eggs
- when cooking with egg substitutes, there will be color (added carotenoid) and flavor differences - eliminated yolk
28
when eggs are held in the refrigerator for too long
loss of carbon dioxide makes eggs more alkaline, old eggs = need to increase acidity
29
milk and milk products - whey
whey has lactose
30
milk and milk products - composition and nutritive value
low in iron and vitamin C
31
milk and milk products - processing- where to store if unopened?
dry storage if unopened
32
buttermilk in place of regular milk in a recipe
increase the baking soda
- buttermilk is more acidic = need to increase base
33
sweet acidophilus milk
skim milk plus lactobacillus acidophilus bacteria which reduces lactose
34
use of milk in food preparation- when milk is heated & to prevent curdling
- when milk is heated, whey protein precipitates out on bottom of pan or on surface of milk
- to prevent curdling, add an acid slowly and agitate - an acid precipitates casein in milk
35
butter
at room temp, hydrolytic rancidity (uptake of water) leads to flavor changes in butter (saturated fat)
- saturated fats take up water
- unsaturated oils are more subject to oxidative rancidity (soybean oil) (uptake of oxygen at a double bond in an unsaturated fat)
36
cream
heavy or thick > 36% fat
medium 30-36% fat
whipped cream 35% fat
37
cheese
- uncured - refrigerate immediately (cottage cheese, cream cheese)
- cured - additional whey removed, salt added, ripened over time
- %moisture content high to low: cottage (79), cream, mozzarella (45-55), camembert, bleu, Swiss, cheddar, gorgonzola, parmesan (31)
38
wheat flours
graham, whole wheat - entire grain, use freshly ground, spoils quickly due to fat in germ
39
hard wheat bread
strong gluten; bread highest in protein - 11.8%
40
all-purpose (blend of hard and soft wheat)
less gluten; 10.5% protein, used in bakery
41
pastry (soft wheat)
weaker gluten; 7.9% protein, used in bakery
42
cake (soft wheat)
least and weakest gluten, more starch, 7.5% protein, used in bakery, least amount of protein
43
baked flour mixtures - gluten
gluten gives elastic properties, forms framework, holds in leavening agent; made from gliadin and glutenin (when you add a liquid and blend them together) through process of hydration and mixing
44
adding bran to gluten
decreases the volume of the end product
- increase flour and liquid to compensate -> adds strength
45
leavening agent - steam
expands the hollow shell formed by flour and egg
46
leavening agent - air expands
when heated before proteins coagulate and retain it
47
leavening agent - carbon dioxide
- from action of yeast on sugar, yielding carbon dioxide and alcohol
- from action of acid on baking soda (sodium bicarbonate)
- sour milk = more acidic, can add lemon juice
- baking powder: provides both the acid and the alkali needed for reaction
- old baking powder is more alkaline
- baking soda and corn starch can provide CO2
48
sugar - hygroscopic
modifies texture by tenderizing
49
sugar - too much sugar
- results in coarse cells, thick walls, a shiny crust, and a crumbly product
- weakens the gluten by holding water
50
quick breads and yeast
quick breads don't use yeast
51
quick breads ingredients
egg and flour are basic ingredients
52
quick breads - excess mixing
stirred until moisted, not beaten
- loss of CO2 and overdeveloped gluten
- tunnels from top to bottom, tough, heavy product
53
types of cake - shortened cake
layer, pound cakes
- comparatively large amount of fat; uses chemical leavening
54
types of cake - layer cake
baking powder
55
types of cake - pound cake
air and steam
56
types of cake - rich cake
increased fat, sugar, egg; increases keeping quality. lasts longer because crumb is dense
57
types of cake - gold cake, white cake, yellow cake
egg yolks; egg whites, whole egg
58
cakes - alterations in the amount of sugar
the more sugar, the more time is needed to reach the elevated coagulation temperature of gluten. as sugar increases, the volume of cake increases up to the point where the volume is so great and the gluten is so weak that the gluten strands snap and the cake falls in the center (gummy, crystalline appearance - sticky and shiny). water is needed to develop gluten.
59
pastry- lard and oil
are each 100% fat; butter and margarine are only 80% fat
60
pastry- pie crust tenderness
is enhanced by using oil, soft fats, or fat cut into very small pieces. flakiness is promoted by leaving fat in coarse , larger particles
61
what happens to batters and dough when flour goes up in product
the product becomes more dense
62
straight dough method
all ingredients are added before dough is allowed to rise
63
sponge dough method
proofing time (final rising of the dough) is shortened: use strong flour, high in protein (bread flour)
64
waxy starches
corn, rice, sorghum have only amylopectin
- branched fraction: 1,4 and 1,6 alpha glycosidic linkages
65
thickening ability of starches- what is the most effective?
potato is most effective
66
gelatinization
is the swelling that occurs when starch is heated in water close to the boiling point. heat dissociates bonds, water moves in and swells granules. friction is created causing paste to thicken
67
role of sugar in gelatinization - when to add acid?
add an acid when cooking is complete because acid breaks down starch and will produce a runny product
ex:lemon meringue
68
retrogradation
gritty texture
- undesirable - reduces the quality of food
- examples - staling of starch products, such as bakery goods; separation when a gravy thaws; old pudding; stale breads
69
starch uses in food prep - white sauce?
white sauce
- melt fat, add flour (roux-half fat, half flour)
- to get a clear, shiny, translucent sauce, use cornstarch as thickener
70
candies - types - small crystals
fondant, fudge, more ingredients that interfere with crystallization: milk, chocolate, corn syrup)
71
how to make candies
heat sugar and liquid
- acid, fat, protein added, softer it will be
72
candies - how is crystallization prevented?
is prevented by adding interfering substances (fat, milk) or by increasing the concentration of sugar
73
ice cream is a product of
crystallization
74
ice cream formation
fat interferes with crystal formation, making crystals small and smooth
- not adding enough fat produces a grainy ice cream with large crystals
75
gelatin - incomplete protein
no tryptophan
76
gel formation - enzymes
- bromelain is an enzyme in fresh or frozen pineapple that breaks down protein and prevents gelation (inactivated by heat 170-180'F) - could use canned pineapple
- papain is a proteolytic enzyme from papaya that will prevent gelation
77
beverages - brew coffee
at 185-203'F for best flavor, at higher temps, tannin is extracted and coffee is bitter
78
who controls food additives
the FDA
79
food additives - emulsifiers
monoglycerides, diglycerides, lecithin, disodium phosphate
80
food additives - sorbitol
humectant (retains moisture), sweetener, bulking agent, limits mold
81
food additives - mold inhibitor
propionate, sodium benzoate (soda)
82
sensory evaluation of food - qualitative (subjective)
uses organoleptic measurements (sense organs) - opinions - to test color, odor, taste, texture
83
sensory evaluation of food - analytical (under qualitative)
differences or similarities, qualities
84
sensory evaluation of food - affective
used with untrained panelists, determine preference, acceptance, or opinions of a product
85
examples of affective sensory evaluation of food
- hedonic rating - scale; facial hedonic - smiling faces - all opinions
86
sensory evalution of food - flavor profile method
descriptive flavor analysis profile (DFAP). trained panel, subjective opinion
87
objective measures of food quality - viscosimeter (viscometer)
measures viscosity of liquids that flow; measures the flow on an incline plane or on a rotational basis
88
objective measures of food quality - line-spread test
measures viscosity of liquids or semi-solid foods that flow in a flat surface
89
food biotechnology and genetic engineering (GMO)
scientific techniques used to produce specific desired traits in plants, animals or microorganisms through the use of genetic knowledge
90
composition of food
-food synergy is the additive influence of foods and constituents which, when eaten, have a beneficial effect on health
-collective additive results is better
91
probiotics
live microbial food ingredients that benefit health (kefir, acidophilus, milk, yogurt)
92
prebiotics
nondigestible food ingredients that support growth of probiotics
- fibers (fructooligosaccharides (FOS), soluble dietary fiber, found in onions, garlic, asparagus
- inulin (fructose polymer)
93
functional foods
provides more functions than the basic nutritional benefits
94
what foods have resveratrol
grape juice, red wine, and fatty fish
- which reduces platelet aggregation
95
phytochemicals - indoles
cruciferous vegetables (sulfur) - detoxification of carcinogens
96
phytochemicals - isoflavones
anthoxanthin in soybeans - lower elevated cholesterol
97
labeling and packaging claims
nutrition labeling and education act - fda
98
label regulations - low kcal
no more than 40 kcal/serving
99
label regulations - low fat
3 grams or less per serving
100
label regulations - low sodium
no more than 140 mgs / serving
101
label regulations - gluten free
< 20 ppm
102
label regulations - organic
minimum of 95% organic ingredients; up to 5% non-organic allowed
103
% DV
% of the daily value for each nutrient a serving of the food provides, based on a 2000 kcal intake. increase DRV (daily reference value) and RDI (reference daily intake)
104
packaging claims - health claims
based on authoritative statements from a scientific body of the US Gov or the national academy of sciences.
" a calcium,-rich diet may help prevent osteoporosis"
105
packaging claims - qualified health claims
emerging evidence of a relationship, but not conclusive. requires a disclaimer: " Evidence suggests but does not prove that..."
106
packaging claims - structure function claims
-may describe the role of a nutrient or dietary ingredient intended to affect the normal structure or function of the human body
-may be used without FDA permission "fiber maintains bowel regularity"
