Inman Need to Know - Food Science

super important things to know from inman study materials

Crispness (state of turgor) is due to what in fruits and vegetables?

the osmotic pressure of water-filled vacuoles

what accelerates the ripening of fruits during storage?

ethylene gas

what can delay aging of apples?

storing them in a controlled atmosphere (reduced O2 environment)

what ripening characteristic do peaches, pears, bananas, apples, and tomatoes have?

they are climacteric and ripen post-harvest

what does chlorophyll transform to when combined with acid?

pheophytin (olive green color)

what does chlorophyll transform to when combined with an alkaline agent?

clorophyllin (bright green color; food may have mushy texture because hemiceullose is broken down)

what pigments are least affected by changes in pH?

carotenoids

what are lycopenes?

a type of carotenoid that acts as an antioxidant; it is a phytochemical

what pigments are most affected by changes in pH?

anthocyanins (a type of flavonoids); red, blue, and purple pigments

How do anthoxanthins or flavones react to alkaline environments/ when they are cooked in aluminum?

they turn yellow (flavones chelate aluminum)

when should berries and mushrooms be washed?

immediately prior to serving/ using (otherwise will get mushy)

how many oranges does it take to make one quart of juice?

12

How do starches change during storage?

they change to sugar (old potatoes taste sweeter, cook to a darker brown, and are softer in texture)

how does cooking previously frozen foods differ from fresh foods?

cooking time is shorter than fresh because blanching/ freezing have made them tender

How to best reduce strong flavor when cooking cabbage

cook for a short time, cook in a large amount of water, and keep the lid off initially to let acids escape

how many #10 cans come in a case?

6

how many cups in a #10 can?

13

what entity grades canned/ fresh fruits and vegetables?

USDA

what is collagen in meat?

structural part of tendon that surrounds muscle

what happens to collagen in heat?

is hydrolyzed to gelatin and becomes tender

what is elastin in meat?

found in ligaments and cartilage, is yellow in color

what happens to elastin in cooking?

it is resistant to heat so little change occurs with cooking

pork is a good source of which micronutrient?

thiamin

what meats are high in calcium?

fish canned with bones, oysters, shrimp

how does myoglobin change with oxygen exposure?

turns red, then brown, then eventually green (O2 gradually breaks down myoglobin)

how does aging affect meat?

increases tenderness

what biological change makes meat more tender?

increases in the water holding capacity of the muscle

how does acid and salt increase meat tenderness?

increases in the water holding capacity of the muscle

how can the storage life of meat be extended?

through vacuum-packing in an O2 impermeable film (sous-vide) and storing at 0 degrees C/ 32 degrees F

How does removing O2 and replacing is with other gases (CO2/ nitrogen) affect shelf life?

extends it; prevents deterioration by slowing respiration

what is mandatory for meat and done by the USDA at slaughter?

inspection; shown with round purple stamp “USDA inspected and passed”

what is voluntary for meat and done by the USDA at slaughter?

grading; grade appears on a shield

what temperature is used for roasting?

325 degrees F

what is the safe minimum temp for pork, beef, veal, lamb, steaks, roasts, and fish?

145 degrees F

what is the safe minimum temp for ground beef, ground veal, and ground lamb?

160 degrees F

what is the safe minimum temp for turkey, chicken, and duck?

165 degrees F

what differs in how tough cuts of meat need to be cooked?

they need to be cooked well done because they have more collaged, which needs more time to be softened

what makes cured meats pink?

nitrates added (they are added to inhibit botulism)

what method of cooking should be used for tender cuts of meat near the backbones (loin/ sirloin)?

dry heat (no water involved)

what fat has the highest smoke point?

safflower oil (513 degrees F)

what fat has lowest smoke point?

butter (350 degrees F)

what happens to fats as they become rancid?

there is an uptake of O2 in unsaturated fatty acids

what are characteristics of the healthiest plant oils?

they are highly unsaturated; have more MUFA and are less susceptible to rancidity than those with more PUFA

What cooking method should be used with less tender cuts of meat (bottom round, chuck, brisket)?

moist heat (water involved), because there is more connective tissue

process of braising

flour meat, brown, cover and simmer in liquid, done in oven or range-top

process of simmering

heated in water to 170-185 degrees F with appearance of bubbles

process of steaming

heat over, not in, water

process of stewing

add water or other liquid during cooking

what is papain?

a proteolytic enzyme that is a blend of papaya and salt and tenderizes meat

what is TVP?

texturized vegetable protein; made from soybeans and mixed with ground meats to extend number of servings and lower costs

during receiving, what should be the appearance of fresh fish with the head attached?

bright red gills, and bright shiny skin. if gills are dull and gray, reject it

what is surimi?

purified and frozen minced fish with a preservative, may have egg white or starch added to create desired texture

what can happen if tuna, mackerel, or mahimahi are inadequately refrigerated?

histamine toxicity (scromboid poisoning)

what part of the egg has the most concentrated levels of nutrients?

the yolk

How are eggs graded and what are the grades given?

by candling (passing the egg in front of a bright light), grades are AA, A, and B

what will happen to a fresh whole egg when put in cold water?

it will sink to the bottom (also egg will have a dull, rough shell)

what is syneresis and when does it occur

weeping - liquid released from a coagulated product. occurs when product is cooked at too high a temperature or too low a temp for too long a time; creates a tough, watery product

what is needed to stabilize egg white foam and how does it work?

acid stiffens/ stabilizes egg white foam by tenderizing the protein

what characteristics do egg white need to whip quickest and yield the largest volume?

they should be at room temperature so they have LOWER surface tension

What part of an egg creates the most stable emulsion?

the egg yolk because it has more protein by weight than egg whites

how is custard quality measured?

% sag (higher % = more tender gel)

how will dehydrated eggs affect a custard?

it will be grayer and less yellow, have a stronger egg flavor, and be watery

what are they key differences between egg substitutes and regular eggs?

egg substitutes are often higher in sodium than fresh eggs and have added carotenoids

what happens when eggs are held in the fridge for too long?

there is a loss of CO2 that makes the eggs more alkaline

at what pH does casein form a curd?

4.6 (acidic)

what is whey?

the liquid that drains from the curd of clotted milk (contains lactose, water soluble vitamins, minerals)

what micronutrients is dairy low in?

iron and Vit C

what type of processing allows milk to be stored without refrigeration if it is unopened?

UHT (ultra-high temp) aseptic packaging

what is cultured buttermilk?

a fermented milk where lactic acid bacteria has been added to skimmed or partly skimmed milk

what adjustments need to be made when using buttermilk in place of regular milk in a recipe?

increase the baking soda

what is sweet acidophilus milk?

a fermented milk that is skim milk with added lactobacillus acidophilus which reduces lactose

what happens to milk when it is heated?

whey protein will precipitate out on the bottom of the pan or on the surface of the milk

how much of butter is milk fat?

butter is 80% milk fat

what happens to butter when it is stored at room temperature?

hydrolytic rancidity (uptake of water) leads to flavor changes (in saturated fat)

what is the fat % in heavy (thick) cream?

>36%

what is the fat % in medium cream?

30-36%

what is the fat % in whipping cream?

35%

what is uncured cheese?

those that need to be refrigerated immediately (cottage cheese, cream cheese)

what is cured cheese?

those with additional whey removed, salt added, and ripened

what cheese has the highest moisture content?

cottage cheese (79%)

what cheese has the lowest moisture content?

parmesan (31%)

what is processed cheese?

a blend of several natural cheese (American cheese), with an emulsifier added. better for cooking because fat will not separate out

what is added to quick-cooking cereals

disodium phosphate

memorize flour types