ansc 255 exam 2

what determines meat quality

visual appeal

palatability

what is the most important characteristic at purchase

meat color

what proteins control meat color

hemoglobin

myoglobin

what causes meat color variation

species

sex

age

muscle location

function of myoglobin

oxygen transport

main source of iron in meat

composition of myoglobin

heme ring

globin

heme ring has --- which determines color

6th ligand

states of myoglobin

deoxymb

oxymb

metmb

what is deoxymb

most stable

nothing bound to ligand

purple color

what is oxymb

most desirable

least stable

o2 bound to ligand

red color

what is metmb

least desirable

h2o bound to ligand

brown color

what causes mb oxidation

oxygen

heat

light

oxidants

palatability

desirable taste and texture properties

properties of palatability

tenderness

juiciness

flavor

appearance

3 factors of tenderness

connective tissue

sarcomere length

proteolytic enzymes

what is connective tissue

background toughness

collagen and elastin

what is connective tissue impacted by

age

muscle location

sex (males have more)

what is sarcomere length

actin myosin cross linking

toughening, tightly packed

what are proteolytic enzymes

degrades proteins post mortem

type of proteolytic enzymes

calpains (m calpain, u calpain, calpastatin)

what is the “fourth factor” of tenderness

marbling

how does marbling impact tenderness

acts as a lubricant for chewing

what impacts juiciness

intramuscular fats

water

how does intramuscular fat impact juiciness

acts as barrier for moisture loss

melts during cooking

what is flavor

gustatory and olfactory

factors of flavor

sex

muscle location

postmortem aging

processing ingredients

lipid oxidation

objectives of cooking

safety (kill pathogens)

improve palatability

types of cookery

high temperature

low temperature

reasons for processed meat

preservation

flavor/palatability improvement

convenience

adding value

2 ingredients

meat

non meat

what are the types of non meat ingredients

important (water, salt)

optional/other (phosphates, seasoning, nitrite/nitrate)

what are the key processing ingredients

meat

water

salt

phosphate

seasonings

nitrite

what is the meat ingredient

source of protein

source of fat

what is the water ingredient

disperse ingredients

temperature control

increase juiciness

what is the salt ingredient

extracts proteins

add flavor

helps with water holding capacity

what is the phosphate ingredient

increases pH

improves water holding capacity

what is the seasoning ingredient

provides product indentity

what is the nitrite ingredient

increases preservation/shelf life

sets cured pink color

what does nitrite do in curing

prevents warmed over color

fix reddish pink color

inhibit micro growth

what does sodium erythorbate/ascorbate do in curing

curing accelorator

alternatives to nitrite

vegetables (celery juice, radishes, lettuce, zucchini squash)

methods to curing whole muscles

dry rub

pickle/brine

what is dry rub

no water added

slow

increases quality

bone sour

what is pickle/brine

use water

immerse or soak (slow)

pump/inject (rapid disperse)

fast

decrease quality if too fast

possible micro growth

types of sausage

fresh

smoked, uncooked

fully cooked

luncheon loaves

dry and semi dry

what is fresh sausage

uncooked

not smoked

not cured

ex. breakfast sausage, bratwurst

what is smoked, uncooked sausage

no thermal process

not cured

“cold smoke”

least common

ex. traditional kielbasa

what is fully cooked sausage

thermal processed (rte)

may or may not be smoked

usually cured

not shelf stable

most popular

ex. hot dogs

what is luncheon loaves

fully cooked, rte

3 types: whole muscles (restructured), chunked and formed, ground sausage

ex. boneless ham, roast beef, bologna

what is dry and semi dry sausage

reduced pH (

what are the dairy breeds

holstein

jersey

brown swiss

guernsey

ayrshire

milking shorthorn

holstein

dutch origins

most commercially used breed in the US

high volume

jersey

english origins

smallest in body size

most heat tolerant breed

very high butter fat milk

brown swiss

swiss origin

considered oldest breed

milk has high protein to fat ratio

good for cheese

guernsey

english origin

milk has beta carotene (vit a)

yellow/golden color milk

ayrshire

scottish origin

most easily to adapt to environment

found globally

milking shorthorn

great british origin

duel purpose breed

milk has high protein to fat ratio

dairy family tree

milk

add something (heat, bacteria, salt, flavor)

remove something (water, fat, lactose)

mammary gland

commonly called the udder

inguinal canal

has arteries, veins, lymph vessels, nerves

before milking, udder can weight up to ---kg

50

cow udders have --- sections

4

posterior of the cow udder makes --% of milk

60

udder portions are drained by the ---

teats

alveoli

tissue that secretes milk (epithelial cells)

remove water and nutrients from body to convert to milk

major ducts

do not secrete milk

gland cistern

continuous with teat cistern

collection of 15-20 major ducts

annular fold

dense connective tissue before entering teat

teat cistern

made of many folds

holds 0.5-1.5 oz of milk

teat meatus/streak canal

3-5 convex epithelial projections (star shaped)

prevents escape of milk

barrier to bacterial and foreign material

at milking ---% milk in cistern and major ducts

40

at milking, ---% milk is in the alveoli

60

stages of dairy cows

calving

lactation

dry cow

stages of lactation

fresh cow

early lactation (peak, breed)

mid lactation

late lactation

length of fresh cow

20 days

length of early lactation

20-150 days

when is peak lactation

40 day

when is breeding

90 day

how long is mid lactation

150-210 days

how long is late lactation

210-305 days

milking process

disinfect udder

strip udder

wipe disinfectant off udder

place machine on udder

disinfect udder

what is the udder disinfected with

iodine

milk composition

water

carbohydrates

fat

protein

vitamins/minerals

how much water is in milk

87-89%

how many carbs are in milk

5%

how much fat is in milk

3%

how much protein is in milk

3%

how many vitamins/minerals are in milk

0\.7-1%

lactose

2 anomers

can convert back and forth between anomers

solubility is temperature dependent

what are the 2 anomers

a lactose

b lactose

what is a lactose

soluble at high temperatures

crystalizes at low temperatures

what is b lactose

crystalizes at high temperatures

soluble at low temperatures

over --- fatty acids identified in milk

400

saturated fat concentration in milk

65%

monounsaturated fat concentration in milk

30%

polyunsaturated fat concentration in milk

5%

protein in milk is considered ---

complete

protein families

casein

serum ‘whey’

casein

82% of protein

contains phosphorus

will precipitate at pH 4.6

random and open structure

stable to heat treatment

whey

18% of protein

no phosphorus

remain in solution at pH 4.6

contains large amounts of sulfur containing AA

more sensitive to heat (good for yogurt and meat products)