ice cream

milk composition (6)

water

fat

lactose

proteins (caseins and whey proteins)

vitamins

minerals

% water in cow milk

87%

fat in milk (2)

triglyceride in membrane-enclosed “fat globules”

separates out as cream, floating to top

lactose in milk

main carbohydrate

casein proteins in milk (2)

80% of protein

insoluble and give milk white color

whey proteins in milk

soluble proteins, several different forms

vitamins in milk

fat soluble vitamins are in milk fat

water soluble vitamins are in nonfat component

minerals in milk

many, primary calcium and phosphorus

most milk sold in USA is… (2)

homogenized and pasteurized

pasteurization (3)

destroys pathogens by subjecting to heat

most common is high temperature for short time (71.67C for 15 secs), will not curdle

another method to ultrahigh temperature (137.78C) for 2 seconds, sterilizes milk and increases shelf life

homogenization

reducing size of milk fat globules so that they are dispersed through the liquid of milk, no creaming

churning (4, whipped cream, butter, buttermilk, ice cream)

fat globules must be broken if fat is to be recovered

agitation, beating, or whipping are physical methods, basis of butter making

air incorporated as foam (whipped cream) in agitation, continued agitation breaks foam and yields granules (butter, small particles) and liquid (buttermilk), granules composed primarily of milkfat

ice cream similar process but with frozen water as ice crystals, and air

emulsification

things like egg yolks helping milk fat and water mix

fat byproducts (5)

edible shortening, soaps, oils, lubricants, livestock feed

bone byproducts (3)

bonemeal, glue, buttons

blood byproducts (2)

sausage components, blood meal (animal feed or fertilizer)

hide byproducts (3)

leather, glue, gelatin

pancreas byproducts

insulin, pig insulin historically main source, now made in bacteria

glands byproducts (2)

hormones, pharmaceuticals

calf stomach byproducts

rennet (milk coagulant for cheese making)

intestines byproducts (3)

pet food, animal feed, sausage casings

hair byproducts

paint brushes

curd contains… (4)

casein proteins, fat, minerals, vitamins

whey contains… (5)

whey proteins, lactose, vitamins, minerals, water

acid coagulation

caseins in milk are insoluble at pH 4.6 for cow and pH 4.2 for goat (isoelectric point of casein)

lowering pH to this point will cause casins to coagulate

rennin coagulation

protein digesting enzymes cause caseins to coagulate

rennet widely used by cheesemakers to produce cheese curd

rennet origin

calf abomasum and contains enzyme rennin

also manufactured from vegetable materials or is recombinant

cheese making (2)

different cheeses made in different ways, not just by acid or rennet coagulation

majority of cheese come from curds but some are made from whey (ex. ricotta)

cheese classifications (4)

very hard, hard, semisoft, soft

very hard cheese (2)

romano, parmesan

hard cheese (3)

cheddar, provolone, swiss

semisoft cheese (4)

muenster, limburger, blue, gorgonzola

soft cheese (2)

brie, cottage

milk products (5)

cheese, ice cream, evaporated milk, condensed milk, cultured milk products

ice cream

basic ingredients: milk fat (cream), sugar, eggs, etc

air bubbles introduced as the ingredients are whipped results in the structure of ice cream

evaporated milk

removes most of the water via a vacuum pan

condensed milk

addition of large quantity of sugar to evaporated milk

cultured milk products (3)

from fermentation of milk or milk products by bacteria that produce lactic acid

include buttermilk, sour cream, and yogurt

bacterial species used depends on the desired product

meat aging

held in the cold at 1.1-3.3ºC for 10-14 days (aged beef must be >14 days)

allows enzymic activity to break down complex proteins, improves flavor and tenderness

meat carcass

dressed, slaughtered animal (lacks gut contents, head, skin, reproductive tract, feet)

meat curing

processing to impart flavor, enhance color and preserve meats by injecting salt, sugar, and sodium nitrite

meat cutability

proportion of lean to fat of carcass that is saleable as trimmed (boned or partially boned) retail cuts

meat kosher

meat from animals slaughtered and inspected according to jewish law

meat natural casings

middle wall of small and large intestines of cattle, hogs, sheep, and goats

do not need to be identified by species on label unless used for all beef products

meat nitrates/nitrites

for curing and preserving to prevent clostridium, botulinum spore growth (botulism)

meat palatability

quality of taste or flavor that a meat product imparts when eaten

processed meat

meat that has been changed by cooling, canning, drying, or a combination

meat scalder/dehairer

machine used to loosen and remove hair on swine by immersion in hot water (60-62ºC) while mechanically scraping the carcass

meat smoking

method of processing used to reduce surface bacterial populations, enhance flavor, and impart color to meats

veal meat

very young (milk-fed) calves usually not over 12 weeks of age at slaughter

dressing percentage

(carcass weight)/(live weight)

cattle dressing %

60%

swine dressing %

72%, high because doesn’t have rumen and skin is usually left on after slaughter

sheep dressing %

50%

dressing % and fill

digestive tract and gut fill, could account for 25% of BW

dressing % and fatness

fatter tend to have higher dressing %

dressing % and muscling

more muscled (with fatness) have higher dressing %

dressing % and type

bulkier dress higher than thin

dressing % and pregnancy

later stages of pregnancy dress lower

dressing % and wool

heavy fleece lower dressing %

federal inspection stamp (3)

stamped with food grade vegetable dyes

indicates meat was determined to be “wholesome and fit to eat”

processing facilities assigned different number by federal government to determine origins of meat

carcass quality grades (based on? 8 grades)

based on maturity and marbling

highest to lowest: prime, choice, select, standard, commercial, utility, cutter, canner

carcass yield grades (3)

cutability, based on quantity of boneless, closely trimmed retail cuts from round, loin, rib, and chuck wholesale cuts

determined by: amount of external fat over ribeye muscle, area of ribeye muscle, hot carcass weight, kidney/pelvis/heart fat

1-5, 1 leanest and highest grade

pork carcass grading (3)

US highest to lowest: no. 1-4, utility

determined by quality of lean, measure of fat, expected yield of trimmed hams/loins/picnic shoulders, and boston butts (main wholesale cuts)

USDA grades rarely used; in house grading used for pork carcass value

lamb quality grading

high to low: prime, choice, good, utility, cull

based on conformation, maturity, flank fat streaking within and upon flank muscles, and firmness of the lean flesh and external fat

lamb yield grade

quantity of boneless, closely trimmed retail cuts from the major wholesale cuts (leg, loin, rack, shoulder)

high to low: 1,2,3,4,5

lamb vs mutton

under 14 months with break joint on at least one of front shanks is lamb