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Flashcards in Exam 3 Meat to Muscle Deck (49)
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1

homestasis

-maintenance of a physiologically balanced internal environment
-blood pressure
-oxygen concentration
-energy supply
-temperature
-pH

2

blood pressure post mortem

vaso contractor (reduced diameter of blood vessel)

3

oxygen concentration post mortem

oxygen supply declines so body trys to use up only remaining supply from myoglobin

4

energy supply post mortem

-declines
-only 2 ATP produced

5

temperature post mortem

temp declines

6

pH post mortem

when lactic acid accumulates it goes from 7 (living) to 5 (post mortem)

7

onset of rigor mortis

-stiffness follows removal of blood and oxygen
-muscles stiffen bc ATP isn't produced and actin and myosin bond together 100%

8

rapid metabolism post mortem

-slower chill after death
-caused by more heat from faster/ rapid muscle metabolism
-faster pH decline

9

normal muscle metabolism post mortem

-normal/faster chilling after death
-leads to more tender meat
-more ATP
-reduced bacterial accumulation
-more efficient

10

anaerobic muscle metabolism

-no oxygen
-fast twitch fibers
-pyruvate
-lactic acid build up
-2 ATP
-higher pH

11

aerobic muscle metabolism

-oxygen
-slow twitch fibers
-pyruvate
-TCA cycle
-34 ATP

12

when the muscle stops receiving blood, oxygen is no longer present and _________ metabolism begins

anaerobic

13

glycogenolysis

-glucose molecules are cleaved from glycogen/ breakdown of glycogen to glucose

14

glycolysis

-glucose goes through 10 reactions
-results in 2 pyruvate

15

pH change before and after death

-living muscles: 7.2
-12-24 hours after death: 5.3 - 5.8
-inosine to hypoxanthine

16

substances with high amounts of H+ following death

-low pH (more acidic)
-pH = -log [H+]

17

r-value

concentration of inosine divided by concentration of adenosine
-indirect measurement of ATP status
-breakdown of ATP = higher r-value

18

gravimetric fragmentation

-weight of meat left over on the top of the screen
-smaller number = more tender

19

factors influencing pH drop

-gegentics/ muscle fiber type
-stress (body temp, respiration, blood pressure)
-amount of glycogen present
-postmorte temperature/ cooling rate

20

fast-twitch fibers

produce more lactic acid bc amount lactic acid is directly proportional to amount of carbohydrates broken down for fuel

21

post rigor muscle

-stiff
-actin and myosin is tightly connected
-chill boned muscle

22

pre rigor muscle

-still flexible
-water bound in expanded spaces between myosin and actin
-hot boned muscle

23

5 batter preparations

-cold boned/ traditionally minced
-hot boned/ warm minced with no chill
-hot boned/ chill minced with CO2
-hot boned/ chill minced after crust-freeze-air-chill
-hot boned/ chill minced after 1/4 section/crust-free-air chill

24

caudal

-sarcomere length
-longer sarcomere length = more tender

25

medial

-pH
-r-value

26

cranial

gravimetric fragmentation index

27

3 types of protein

-myofibrilliar (contractile element proteins)
-sarcoplasmic (metabolic proteins)
-stromal (connective tissue proteins)

28

myofibrilliar proteins

-contractile element proteins
-9.5%, 50-55%
-salt soluble
-ex. myosin, actin, troponin, titin

29

sarcoplasmic proteins

-metabolic proteins
-6%, 30-35%
-ex. water enzymes, myoglobin

30

stromal proteins

-connective tissue proteins
-3%, 15-18%
-non-soluble
-ex. collagen, reticulum