I A Food science & nutrient composition: F&V, meat/poultry/fish Flashcards
crispness is AKA..?**
state of TURGOR (rigidity)
composition of F&V
mostly water, some carbohydrates and vitamins/minerals
crispness is due to what?***
OSMOTIC PRESSURE of WATER-FILLED VACUOLES
with age, F&V increase in what two compounds?
hemicellulose & lignin (a non-CHO substance not significantly softened by cooking)
what is the limiting AA in soybeans?
methionine
chemical changes in F&V are due to?
enzymes
when F&V ripen, starch is changed to?
sugart
order of ripening: pectic acid, protopectin, pectin
protopectin –> pectin (ripe) –> pectic acid (overripe)
what accelerates the ripening of fruits during storage?***
ethylene gas
out of these: tomatoes, onions, avocados, peaches, oranges, bananas, corn on the cob, pears- which ripen best at room temperature?
avocados, bananas, pears, tomatoes
aging in delayed in apples stored in what kind of environment?*****
controlled atmosphere (reduced oxygen) [ROP]
when should berries and mushrooms be washed?*****
JUST before serving!!
fruits low in ______ darken rapidly when cut due to enzymatic action; therefore, do WHAT to prevent?
vitamin C; dip in citrus juice, add sugar before freezing, heat to boiling
of oranges that yields 1 QUART of orange juice**
one dozen (12)
1 quart = ? cups***
4 cups (you know this, but quart = quartile, 1/4)
1 pint = ? cups***
2 cups
cooking vegetables softens what compound?
cellulose (aka plant fiber)
density of a syrup in packaging of fruit is often expressed as a % by weight of what sugar: fructose, glucose, sucrose?
sucrose - measured with a Brix hydrometer
what pigments are LEAST affected by changes in pH?*****
carotenoids (yellow, orange)
what pigments are MOST affected by changes in pH?**
flavonoids (red, blue, purple)
green (chlorophyll), yellow and orange (carotenoids) pigments are all (soluble/insoluble) in water
insoluble
flavonoids are (soluble/insoluble) in water
soluble - therefore, probably likely why they are affected so much by changes in pH
name the color:
- pheophytin
- chlorophyllin
- lycopenes
- anthocyanins
- anthoxanthins
- pheophytin = olive green
- chlorophyllin = bright green
- lycopenes = red
- anthocyanins = red/blue/purple
- anthoxanthins = white
what pigment/compound acts as an antioxidant?
lycopene (red - watermelon, tomatoes, overtones in apricots)
what makes up the group of flavonoids?***
1) anthocyanins - red/blue/purple
2) anthoxanthins - white
add acid to green vegetables, what happens?***
olive green = PHEOPHYTIN
add alkaline (baking soda) to green vegetables, what happens?***
turns bright green = CHLOROPHYLLIN, MUSHY, hemicellulose broken down
what is glutamic acid?
form of salt - MSG
onion & cabbage get their flavor from?
sulfur
how to cook brussel sprouts for best flavor?
uncovered with little water
____ cause an astringent feeling in the mouth
tannins (aka like an underripe banana)
canned fruits and vegetables have what grades?*****
Grade A, B, C
fresh produce has what grades?**
Fancy, Extxra #1, #1, Combination, #2
F&V are graded by whom**
USDA
what is the green color under the skin of potatoes due to?
chlorophyll that develops when potato is exposed to light during storage
in potatoes, starch changes to ___ during storage***
sugar
older potatoes taste ____, cook to ___ color, and are ___ in texture
OLDER potatoes change in taste, color, texture:
- taste sweeter (starch –> sugar)
- cook to a darker brown (Maillard reaction w/ sugar)
- softer in texture
how should you cook acidic vegetables that need more time to cook?
more water, no lid
frozen vegetables have a (shorter/longer) cooking time than fresh vegetables; why?**
SHORTER- BLANCHING & FREEZING have made them TENDER
best way to cook broccoli?
microwave: less time, same flavor, retains color slightly better, better retention of vitamin C, no large difference in eating quality
when cooking cabbage, how can you minimize the development of a strong flavor?***
cook for a SHORT time, keep kid off initially to let acids escape, cook in a LARGE AMOUNT OF WATER
how many #10 cans come in a case? how many cups is a #10 can?***
6 cans in a case; 13 cups per can
muscle is composed of?***
bundles of fiber- myofibrils
what holds the fibers in bundles together?
sheet of connective tissue
what is collagen?***
STRUCTURAL part of tendon that surrounds the muscle
what happens to collagen in heat?***
HYDROLYZED to GELATIN, becomes TENDER
what happens to elastin in heat?***
RESISTANT to heat, LITTLE CHANGE in cooking
where is elastin found?
ligaments, cartilage, yellow color
elastin vs. collagen in cooking
- elastin = resistant to heat
- collagen = hydrolyzed to gelatin, becomes tender
fat is AKA
marbling
in relation to meat, what is a finish?
amount of fat cover on carcass
pork is a good source of?***
thiamin
nutrients in meat/poultry/fish
- 16-23% protein
- CHO: glycogen in liver, glucose in blood
- vitamins/minerals: thiamin (B1), niacin (B3), riboflavin (B2), iron, copper
calcium content is high in fish that are…?
canned with bones, oysters, shrimp
what is TVP?
textured vegetable protein
what does TVP do?
added into simulated meat products, mixed with ground meats to extend number of servings and lower costs
main contributor to meat color is?***
MYOGLOBIN
progression of meat changing colors (oxidation of meat)***
myoglobin + oxygen –> red –> brown –> green
why does meat turn green?***
FURTHER MYOGLOBIN BREAKDOWN, oxidation of the PIGMENT (NOT bacteria)
aging of meat increases….
tenderness
change in muscle protein is brought about by ____ which do what?***
ENZYMES- INCREASE WATER-HOLDING CAPACITY of the MUSCLE
_____ & ____ increase tenderness by increasing the water-holding capacity of the muscle***
ACID (VINEGAR) & SALT
why do marinades have vinegar?***
vinegar = acid, will increase water-holding capacity of the muscle, therefore increasing tenderness
does physical activity of an animal increase tenderness?
NO
what does vacuum-packing meat in an oxygen-impermeable film or sous vide stored unfrozen at 0C do?***
ANAEROBIC –> extends STORAGE LIFE of meat
problem with anaerobic storage?
worry about clostridiums bacteria d/t their anaerobic nature
what is MAP?
modified atmosphere packaging- air is removed and replaced with gases (i.e. CO2, nitrogen)
inspection and grading of meat is done by whom? when?***
inspection and grading = USDA, done at SLAUGHTER
is inspection and grading of meat voluntary or mandatory?**
MANDATORY
what does the Wholesome Meat Act of 1967 ensure?
that the animal was healthy at time of slaughter and the meat is fit for human consumption (assures wholesomeness)
grading of meat indicates?***
QUALITY
grades of meat
Prime, choice, select, standard
grading of meat is based on?
maturity of animal, marbling of fat, color and texture of lean
what grades have the most marbling? the least?
- most marbling = prime (fattier)
- least marbling = standard (more lean)
2 types of meat specifications
IMPS (Institutional Meat Purchasing Specifications) & NAMP (National Association of Meat Purveyors)
relationship between tenderness of meat and muscle use***
inverse relationship:
- most tender cuts = least used muscles
- least tender cuts = most used muscles
most tender cuts of meat are?***
least used muscles
examples of most tender cuts of meat***
loin, backbone, pork chops
least tender cuts of meat are?***
most used muscles
examples of less tender cuts of meat***
flank, brisket, bottom round
least tender meats use what type of heat?***
moist heat (least tender…most used muscles…flank/brisket/bottom round…moist heat)
most tender cuts use what type of heat for preparation?***
dry heat (most tender…least used muscles..loin/backbone…dry heat)
what temperature is used for roasting meat?***
325F
high temperatures for meat do what?***
increase SHRINKAGE, TOUGHEN
a slow-cooked roast yields how much waste?***
less waste!
when should you insert a meat thermometer?***
BEFORE cooking
safe internal temperature for pork, beef, veal, lamb, steaks, roast, fish***
(meat & fish) = 145F
safe internal temperature for ground beef, ground veal, ground lamb***
(ground) = 160F
safe internal temperature for turkey, chicken, duck***
(poultry) = 165F
what happens to collagen when cooked?***
hydrolyzed to gelatin and sotens
how do tough cuts of meat need to be cooked? why?***
cooked WELL DONE, MORE COLLAGEN that needs to be SOFTENED
heat changes the interior of meat to what color? why?
red –> pink –> brown –> gray; heat denatures globin and iron is oxidized
how can you increase the tenderness of meat? what does it do?
adding vinegar –> lowers pH and INCREASES water-holding capacity of muscle
cured meats are what color? due to what compound?***
PINK - NITRITES
cured meats are AKA
vaccum-wrapped
nitrites inhibit what?***
botulinism
what is dry heat? what cuts of meat is it used for?***
NO WATER involved; used for TENDER cuts (loin, sirloin)
what are examples of dry heat cookery?***
1) frying
2) broiling
3) roasting
4) grilling
what is moist heat? what cuts is it used for?***
using water- used for LESS TENDER cuts with MORE CONNECTIVE TISSUE (bottom round, chuck, brisket)
4 methods of moist heat cookery***
1) braising
2) simmer
3) steam
4) stewing
what is a desirable property of fat that is used in frying?***
high smoke point
what is a smoke point? what should is be around (#)?**
temperature to which fat can be heated before puffs of smoke occur; >400F
what types of meat should you not fry?***
TOUGH cuts- bottom round
what is rancidity?
involves the uptake of oxygen in an unsaturated fatty acid
broiling
form of radiated heat
what phenomenon occurs with roasting? what happens?***
“carry-over cooking” = occurs for about 10 minutes, internal meat temperature rises 15-25F
allow a roast to sit for ____ before carving it***
30 minutes
how should you cook a bottom round?***
(remember: tough cut of meat)
in WATER for SEVERAL HOURS
what is braising?
flour meat, brown, and cover and simmer in liquid
what is simmering?
heat in water to 170-185F with appearance of bubbles
what is steaming?
heat over, not in, water
what is stewing?
add water or other liquid during cooking
the tougher the meat, the more it needs what?***
WATER AND TIME
what type of cooking should be used for fish?
either dry or moist heat
receiving criteria for fish (how should it be when it arrives, when should you reject it?)***
- fresh fish with head attached = bright RED GILLS and BRIGHT SHINY SKIN
- reject if = gills are DULL, GRAY, FISHY SMELL
what is surimi?
purified and frozen minced fish with a preservative, used in analogs, may have egg white or starch added to create desired structure
