Domain 1

what gives vegetables their crispness (turgor)?

osmotic pressure of water-filled vacuoles

what chemical changes occur during ripening

starch -> sugar; protopectin -> pectin -> pectic acid

what gas accelerates fruit ripening

ethylene gas

name three climacteric fruits

tomato, apple, banana

name two non-climateric fruits

grapes, citrus, melon

what pigment turns olive green in acid

chlorophyll -> pheophytin

what pigment turns bright green in alkaline conditions (from → to)

chlorophyll -> chlorophyllin

anthocyanin color changes in acid vs. alkaline

acid = red; alkaline = blue/green

what pigment becomes yellow in alkaline conditions and when cooked in an aluminum pan

anthoxanins (flavones)

how do you prevent enzymatic browning in cut fruit

add acid (citrus), sugar, or heat

why do old potatoes taste sweeter and brown more

starch —> sugar during storage, increases browning (maillard reaction)

what connective tissue becomes tender with heat

collagen -> gelatin

what connective tissue does not soften with heat

elastin

what is the main contributor to meat color

myoglobin

what are the changes in meat color when myoglobin is exposed to oxygen

red —> brown —> green

what do acids + salt do to meat texture

increases tenderness by increasing the water-holding capacity of the muscle

what is the wholesome meat act of 1967?

• claims that the animal was HEALTHY at the time of slaughter

• claims that the meat is fit for human consumption

• wholesomeness

what does the USDA grading evaluate

• animal maturity

• marbling of fat

• color and texture of lean

which grade has the most marbling

prime

what is the safe minimum temperature for poultry

165 F

what is the safe minimum temperature for ground meat

160 F

what is the safe minimum temperature for whole cuts of meat/fish

145 F

what type of heat is used for TENDER cuts

dry heat (fry, roast, broil, grill)

what type of heat is used for TOUGH cuts

moist heat (braise, simmer, steam, stew)

what is surimi

minced fish + additives, used in seafood analogs

what causes histamine toxicity

improper storage of tuna, mackerel, mahimahi

what indiciates a fresh egg in water

sinks

what does candling evaluate

thickness of white; condition of yolk

why do egg foams whip better at room temperature

egg whits at room temperature whip quicker, yield larger volume d/t lower surface tensions

what stabilizes egg white foam

sugar

what effect does acid have on egg white foam

acid stiffens foam by tenderizing protein

what causes the surface of egg yolk to turn green?

• overcooked or allowed to cool slowly

• this is due to a combination of iron (yolk) + sulfur (whole egg) → ferrous sulfide

what is syneresis

weeping of liquid due to overcooking or low cooking temperature

what does lecithin in egg yolks do

acts as an emulsifier (mayo)

what does a high % sag indicate in custards

more tender custard

main protein in milk

casein (80%)

what causes milk to curdle when acid is added

acid precipitates casein

what causes scorching on the bottom of heated milk

whey proteins precipitating

what prevents a film from forming on heated milk

covering or stirring

pasteurization temperatures

145 F for 30 minutes OR 160 F for 15 seconds

what process breaks fat globules into smaller sizes

homogenization

why does evaporated milk look brown

lactose caramelization

which type of rancidity affects butter at room temperature

hydrolytic rancidity

which type affects unsaturated oils (i.e. soybean oil)

oxidative rancidity

what enzyme is used to coagulate casein in cheese

rennet

what separates during cheese production

curd (casein) and whey

which cheeses have the highest moisture content

cottage cheese

why does processed cheese melt smoothly

emulsifiers (disodium phosphate)

how do you prevent cheese from getting stringy

cook briefly at moderate temperature

what part of the grain contains most of the starch and protein

endosperm

where is most of the thiamin found in a grain kernel

scutellum in the germ

what nutrients are concentrated in the germ

fat, vitamin e, thiamin

why does whole wheat four spoil faster

fat in the germ —> rancidity (spoilage of fat and oils)

what is farina

inner portion of the wheat kernel

why should quick-cooking cereals be avoided on low-sodium diets

they contain disodium phosphate

what does disodium phosphate do to cereal

makes cereal alkaline —> particles swell faster

what milling method improves baking quality by separating particle size

air classification

which wheat flour has the strongest gluten

bread flour (hard wheat)

protein content of bread flour

11.8%

which flour has the weakest gluten

cake flour

why is cake flour best for tender baked goods

low protein, weak gluten, high starch

what nutrients are added during enrichment

thaimin, riboflavin, niacin, iron, folic acid

what is self-rising flour

flour + baking powder + salt

what type of wheat is used for pasta

durum wheat

what is semolina flour made from

ground endosperm after bran and germ removal

why should rice be cooked in absorbed water, not excess?

prevents vitamin loss

standard rice-to-water ratio

1 cup rice:2 cups water

what 2 proteins form gluten

gliadin + glutenin

what does gluten provide in baked products

elasticity, structure, gas retention

what happens when bran is added to flour mixture

decreased volume

how do you compensate for bran addition

increase flour and liquid

what causes air to act as a leavening agent

expansion when heated before proteins coagulate

how is air incorporated into batters

beating, creaming, folding, whipping

what produces CO2 in yeast breads

yeast fermentation of sugar

what produces CO2 in chemical leavening

baking soda + acid

what ingredients make up baking powder

baking soda, dry acid, cornstarch

why does old baking powder cause darker crusts

more alkaline

why is salt important in yeast doughs

controls yeast activity

how does fat tenderize baked products

coats gluten —> prevents strong network

why is sugar considered hygroscopic

attracts and holds water

what is the effect of too much sugar in baked goods

coarse crumb, shiny crust, weak structure

what causes tunnels in miffins

overmixing

why does excess sugar cause cakes to fall

weakens gluten —> structure collapses

what causes yellowing in cakes

excess baking soda (alkaline batter)

how do cookies differ from cakes

higher fat, less sugar and liquid

what is the best flour for yeast breads

high protein bread flour

what is the straight dough method

all ingredients mixed before fermentation

what is the sponge method

yeast + liquid + some flour fermented first

why does strong flour shorten proofing time

higher protein = faster gas retention

why do baked goods rise too quickly at high altitude

lower pressure —> gasses expand faster

how to adjust for high-altitude? (___ baking powder, ___ liquid, ___ bake time)

decrease baking powder, increase liquid, longer bake time

two main components of starch

amylose and amylopectin

what is gelatinization

swelling of starch granules when heated in water

how does sugar affect gelatinization

it competes for water —> thinner consistency

what is the effect of acid on starch

it breaks the starch creating a runny product

what is retrogradation

recrystallization of amylose during cooling/freezing

examples of retrogradation

stale bread, watery gravy, old pudding

what controls the crystal size in candy

acid, fat, protein (inhibitors)

what is invert sugar

glucose + fructose from sucrose hydrolysis

example of crystalline candy with SMALL crystals

fudge