Domain 1 - Food Science, Nutrient Composition of Foods Flashcards
what is the water content of fruits and vegetables
75-93%
what is the cause of crispness (state of turgor) of fruits and vegetables
osmotic pressure of water filled vacuoles
what is the limiting amino acid in soybeans
methionine
what is protopectin converted to
pectin (indicates ripe fruit)
what is pectin converted to
pectic acid (overripe fruit)
what accelerates ripening of fruits during storage?
ethylene gas
what temp should frozen fruit be stored at?
0 degrees F
what fruits ripen best at room temp?
avocado, banana, pear, tomato
how can you delay aging in apples?
store in a controlled atmosphere (reduced oxygen)
why do fruits low in vitamin C darken rapidly when cut? how can you prevent this?
enzymatic action - to prevent dip in citrus juice, add sugar before freezing, heat to boiling
what does a Brix hydrometer measure
% sucrose by weight
describe chlorophyll…… more like borophyll
green, Insoluble in water
olive green in acid (pheophytin)
bright green in alkaline (chlorophyllin)
describe carotenoids
yellow/orange, insoluble in water
little color effect in acid or alkaline
lycopene - red in tomato/watermelon, overtone in aprictos (antioxidant/phytochemical)
what are 2 types of flavinoids
anthocyanins, anthoxanthis (flavones) - they are both soluble in water
describe anthocyanins
red, blue, purple
Soluble in water
bright red in acid
bluish tone in alkaline
describe anthoxanthins
white
soluble in water
colorless in acid
yellow in alkaline
what provides flavor in peas and corn
sugars
what provides flavor in onion and cabbage
sulfur
what is glutamic acid used in
MSG (form of salt)
what provides flavor is fruits (3 things)
acids, sugars, aromatic compounds (such as tannins - cause astringent feeling in mouth, underripe banana)
describe Grade A canned fruits and vegetables
fancy - desserts, salads
describe Grade B canned fruits and vegetables
choice - processed
describe Grade C canned fruits and vegetables
standard - puddings, pies
what are the grades of fresh produce
fancy, extra #1, extra #2, combination, #2
what is the green color under potatoes skin due too
chlorophyll that develops when potato is exposed to light during storage
potatoes contain what compound which is a natural toxicant
solanine
what are benefits of microwaving vegetables
less time, retain color, vitamins, not a large difference in eating quality
describe a #10 can (most important!)
6 cans per case, 6lb 9oz, 13 cups in each can, 20-25 servings
describe a #3 can
12 cans per case, 46 oz, 5 3/4 cups, serves 12-15
describe a #2 1/2 can
24 cans per case, 1lb 13 oz, 3.5 cups, serves 6-8
describe a #2 can
24 cans per case, 1lb 4 oz, 2.5 cups, serves 4-6
describe a #300 can
24 cans per case, 14-16 oz, 1 3/4 cups, serves 3-4
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
what happens to elastin in heat
little change, it is resistant to heat
in potatoes, starch changes to what during storage
sugar
muscle is composed of bundles of fibers called what
myofibrils
what holds fibers in bundles
sheet of connective tissue
what identifies a cut of meat
shape of bone (round bone - leg, t-bone - back and ribs, etc)
what % protein is meat/poultry/fish
16-23%
what vitamins/minerals are meat/poultry/fish high in
thiamin, niacin, riboflavin, iron, copper, trace minerals
pork is an especially good source of what
thiamin
calcium content is higher in what types of fish
canned fish with bones, oysters, shrimp
fish has ____ fat and _____ moisture than meat
less, more
why is TVP mixed with ground meats
more servings, lower costs
soy protein adds ______ due to _____ content
juiciness, water
what is the main contributor to meat color
myoglobin
myoglobin exposed to oxygen turns front red to what color
brown, and green with further breakdown
how does acid (vinegar) and salt increase tenderness
increase water-holding capacity of muscle and lowers pH
how should meat be aged and ripened
hold in cold storage for about 10 days
change in muscle protein by enzymes increase _____ of muscle
water-holding capacity
what may extend storage life of meat
anaerobic (sous vide) packaging - vacuum packed, stored unfrozen at 0 C
what is MAP (modified atmosphere packaging)
air in packaging is removed and replaced with gases (carbon dioxide, nitrogen)
when is USDA inspection and grading of meat done
at slaughter
which act assures the consumer that animals are healthy at slaughter and meat is fit for consumption
Wholesome Meat Act of 1967
what are the grades of meat
prime, choice, select, standard
what are grades of meat based on
maturity of animal, marbling, color, texture
which grade has the least marbling and which has the most
standard has least, prime has most
which cuts of meat are most tender
loin (pork chops), backbone
which cuts of meat are medium tender
shoulder (chuck)
which cuts of meat are least tender
flank, brisket
what is the proper temp for a roast
325 F
when should a meat thermometer be inserted
before cooking
a ____ cooked roast yields less waste
slow
what meats have a safe internal temp of 145 F
pork, beef, veal, lamb, steaks, roast, fish
what meats have a safe internal temp of 160 F
ground beef, ground veal, ground lamb
what meats have a safe internal temp of 165 F
turkey, chicken, duck
collagen is hydrolyzed to _____
gelatin
why must tough cuts of meat be cooked well done
they have more collagen which needs more time to be softened
why do meat surfaces become brown
breakdown of pigments
heat _____ globin
denatures
when meats are heated, iron is _______
oxidized
why are cured meats pink
nitrites
what types of cuts should be cooked with dry heat
tender cuts such as backbone, loin, sirloin
what are dry heat cooking methods
frying, broiling, roasting
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
how long should a roast stand before carving
30 minutes
what types of cuts should be cooked with moist heat
less tender cuts with more connective tissue, tough cuts (round, chick, brisket)
how should a bottom round be cooked
in water for several hours
what are moist heat cooking methods
braising, simmering, steaming, stewing
_______ enzymes such as _____ tenderizes meat
proteolytic, papain
fresh fish with head attached should have ______ red gills, _____ skin
bright, shiny
what is surimi
purified and frozen minced fish with a preservative
egg yolk is a naturally occurring _______
oil in water emulsion
a good quality egg is indicated by what
high proportion of thick white
in an egg, what becomes larger with age
air space within the egg
what holds an egg yolk in the center
chalazae (yolk anchor)
what vitamins/minerals is egg rich in
vitamin A, D, riboflavin
what is color of yolk dependent on
amount and type of pigment in a hen’s diet
what are grades of eggs
AA, A, B
grading of eggs is based on what
thickness of white, location and condition of yolk
what is candling
passing an egg in front of bright light to view contents, helpful when grading and judging quality
what are the sizes of eggs
jumbo, xl, large, medium, small, peewee