Exam 2- meat science

the federal law that requires livestock to be made insensible to pain before shackling

HMSA

the harvest step that actually causes the death of the animal is

exsanguinationi

about ___% of the animals blood is removed during esanguination

50%

hogs are scaled in water near __F to loosen the hair

140F

pork carcasses are suspended from the ___ tendon

gambrel

the contents of the thoracic cavity are called the ___

pluck

cattle are classified 30 months or older when one of the ___ pair of permanent incisors has erupted

2nd

the two specified Risk materials removed from all cattle are the ___ and the ___

tonsils

small intestine

the only temporary postmortem inspection status is ___

retained

the typical dressing percentage of a market hog is ___%

75%

the most commonly used organic acid carcass spray is ___ acid

lactic

the maintenance of a steady phsyiologial state is called ___

homeostasis

the hormone released during acute stress that speeds glycogen breakdown is ___

adrenaline

long-term (chronic) stress depletes muscle ___ before harvest

glycogen

the first energy reserve muscle uses to regerate ATP is ___

creatine phosphate

anaerobic glycolysis produces only ___ ATP per gluclose

2

the normal ultimate pH of meat is about ___

5.6

the rigor phase in which ATP is gone and 100% of actomyosin bonds have formed in the ___ phase

rigor

the primary enzyme responsible for postmortem tenderization is ___

calpain

the protein that inhibits calpain activity is ___

calpastatin

cold shortening occurs when pre-rigor muscle is chilled below about ___ C

15C

freezing meat before rigor and then thawing it causes ___ rigor

pre

the form of water most easily lost as purge is ___ water

free

the isoelectric point of meat proteins is about pH ___

0

the most common ingredient used to increase WHC in processed meats is ___

phosphate

the myoglobin form responsible for bright cherry-red, bloomed beef is ___

oxymyoglobin

iron in metmyoglobin is in the ___ Fe3 state

H2O

metmyoglobin reducing ability (MRA) depends on a supply of ___

NADH

the pigment responsible for cooked curedd meat color is ___

nitrosythemochrome

on a colorimeter, the a* value measures ___

redness

ground beef is safe to eat when cooled to ___ F regardless of color

160F

PSE stands for ___,___, and ___

pale

soft

exudative

10 steps of harvest

antemortem inspection

stunning

esanguination

head removal

hide removal

eviscreation

splitting

postmortem inspection

washing and organic acid spray

chilling

6 steps from muscle to meat

exsanguination ends oxygen delivery

creatine phosphate is used up

ATP is depleted

muscle switches to anaerobic glycolysis of glycogen

lactic acid builds up and pH falls

actomyosin bonds become permanent (rigor)

meat color triangle #1

deoxymyoglobin

iron- Fe 2

color- purple

meat color triangle #2

oxymyoglobin

iron Fe2

color- red

meat color triangle #3

metmyoglobin

iron Fe3

color- brown

calcuation for dressing percent

(hot carcass weight/ live weight) x 100

cooler shrink percent calculation

(hot weight-cold weight) / hot weight x 100

three approved methods of stunning

physical

electrical

chemical

tendon used to suspend the carcass for beef

achilles tendon

tendon used to suspend the carcass lamb

achilles tendon

tendon used to suspend the carcass pork

gambrel tendon

which postmortem inspection is temporary

retained

pH 7.2

live resting muscle

pH 5.6

normal ultimate pH

pH 5.2

lowest WHC

isoelectric point

what percent is portion of meat pigment that is myoglobin

80-95%

HMSA (humane methods of slaughter act)

requirnes animals to be rendered insensible before slaughter

stunning (immobilization)

renders animals unconsions

DOES NOT KILL

exsanguination

blood removal

cause of death

stun to stick time

interval between stunning and bleeding

denition

incisor eruption

Specified Risk Materials (SRM)

tonsils and small intestine removed

pluck vs. viscera

thoracic contents vs. abdominal contents

glycogen

stored glucose in muscle

ultimate pH

final pH of meat at harvest

epinephrine or adrenaline

fight or flight hormone

acute stress

fast decline in pH- PSE

chronic stress

glycogen depleted- DFD

halothane gene

mutated SR calcium in pigs- PSE

Rendement Napole (RN)

“acid meat”

more glycogen- low pH

protein denaturation

unfolding of proteins

cold shortening

15-16C chilled before rigor

thaw rigor

frozen pre-rigot

heat shortening

held hot with low pH

heat ring

differential chillding

electrical stimulation

hight ATP depletion low pH

Water holding capactiy

ability meat has to retain water

bound water

tightly held by charged proteins

immobilized water

weakly held layers over bound water

free water

lost as purge and drip

steric effect

more room for water

net charge effect

mrore protein charge

isoelectric point

pH 5.2

phsophates

raise pH

myoglobin

80-95% of meat pigment

deoxymyoglobin

purple

Fe2

vacant

oxymyoglobin

bright red

Fe2

O2

metmyoglobin

brown

Fe3

O2

bloom

20-30 min for oxygen to obtain meat

carboxymyoglobin

red

CO

nitrosylhemochrome

cured pink

hemichrome

brown

premature browning

safety issue

premature pinking

qualityt issue