Topic 8: Meat

Question 1

What makes meat a red color?

Answer 1

the red color is derived from myoglobin (recieves oxygen from blood and serves as oxygen storage in muscle)

color intensity increases with animal age, more exercised muslces are darker red because of more demand for oxygen

older meat cuts look browner

Question 2

What affects the palatability of meat

Answer 2

tenderness, juiciness, flavor, color, texture,

Question 3

Composition of meats

Answer 3

water, muscle, connective tissue, fatty tissue, bone, vitamin B (B1, B2, B12, folate), minerals (zinc, copper, phosphorus, etc.)

Question 4

types of muscles?

Answer 4

cardiac, skeletal & smooth

Question 5

what determines tenderness of meats?

Answer 5

less excercised, younger age, less connective tissues, more fatty tissues

Question 6

what are more tender cuts of meat?

Answer 6

tenderloin, rib, short loin, sirloin (also priced higher)

Question 7

less tender cuts of meat?

Answer 7

chuck, round

Question 8

least tender cuts of meat?

Answer 8

brisket, flank , short plate, shank

would take longer to cook to make soft

Question 9

How are cuts identified?

Answer 9

the bones attached to pieces of meat help to identify the cuts, it also helps confirm the quality of meat

Question 10

what is marbling?

Answer 10

the distribution of fat in the meat

Question 11

what does beef grading depend on in the US?

Answer 11

the USDA, uses a 1-5 rating system to describe the usable carcass meat, as well as a prime>choice>select rating ov marbling in the meat

Question 12

how does grading beef work in Japan?

Answer 12

they use a letter + number grading system raning from A-C (The letters determine lean beef meat) where as the numbers determine marbling (5) or high in fat (1)

A itself has various levels
A1- A5
A1<A2<A3(3-4)<A4(5-7)<A5(8-12)

Question 13

what is US prime steak comparable to in Japan?

Answer 13

A4 steak

Question 14

How can the tenderness of meat be improved (harvesting)?

Answer 14

1. Choice of animal, species, genetics (eg. Black angus cattle, dairy cattle)
2. type of diet fed, grain fed cattle is more tender than hay
3. post slaughter treatment (winthin 6-24 hours muscles enter state of rigor mortis, lasts for 1-2 days, meet should be cookd prior to rigor mortis)

Question 15

What is rigor mortis?

Answer 15

describes when the the meat becomes hard and inextensible as the muscle tissue contracts. ATP is typically admisnistered to induce the the production of lactic acid, decreasing the pH, this prevents the irreversible cross linkage that contracts the muscles in the meat

Question 16

What pH of meat is good quality?

Answer 16

pH of 5.5

Question 17

what are the steps post-slaughter?

Answer 17

1. stretch muscles by tenderstretch (hanging carcass to maximize tension until onset of rigor mortis)
2. optimum temp 15-20 C (prevent cross-linkage formation in muscles so that they dont contract)

Question 18

what are some pre-slaughtering conditions?

Answer 18

Keep animal calm and relaxed before slaughter

Question 19

What meat will a stressed animal result in?

Answer 19

dark-cutting beef, that is darker in color and has a higher pH

if the animal was stressed or excercised before slaughter
- glycogen is depleted in the muscles, and
- less lactic acid will produced during rigor mortis

Question 20

What is dry aging?

Answer 20

a method of tenderizing meat, using protease(an enzyme) to break down the muscle fiber, the meat is hung in a fridge at 1 C-3 C for 1-6 weeks
20% of the original weight (mostly due to
dehydration) is lost, intensifying meat flavor

!!However, the dried or spoiled exterior layer have to be trimmed.

Question 21

What is wet aging?

Answer 21

similar process to dry aging except the meat is vacuum sealed and refridgerated at 1-4 C for 1-6 weeks

Question 22

What are the benefits of wet aging?

Answer 22

shorter time if done in a warm temp (~21 C for 2 days prior to refridgeration and fast aging, UV is used to inhibit microbial growth

Question 23

methods of tenderizing meat?

Answer 23

1. enzymes (breaks down muscular proteins but commercial tenderizer only work for thin cuts, alternatively a more effect tenderizer is injecting a solution into the animal 10 min before slaughter
2. electrical stimulation (speeds up rigor mortis, and accelerates enzyme activity to disrupt the protein structure)
3. high pressure process (meat is subjected to high-pressure shock wave, chages native structure)
4. Salts (seasons meat and improces juiciness by increased water holding capacity)**calcium chloride and ammonium hydroxide leads to tenderization but has an off-flavor
5. Acid & alcohol (disrupts hydrogen bonding in connective tissue)
6. mechanical tenderization: pounding and needling meat to physically break the muscle and connective tissue, but this will reduce juicines
7. Grinding: usually low quality meat is processed and used to create things like burger patties

Question 24

what are some exampes of enzymes for tenderization

Answer 24

(papain from papaya,
bromelain from pineapple,
ficin from figs,
rhyzyme P-11 from fungi)

Question 25

effect of freezing on meat quality?

Answer 25

increases shelf life, but lower water holding capacity, loss of cell juice when thawed, intracellular enzymes are released and can catalyze unfavourable reaction

Question 26

Why does overcooked meat become dry and tough?

Answer 26

proteins coagulate(lowers water holding capacity), water is lost by evaporation

Question 27

how can tenderness be improved during cooking?

Answer 27

more fat in meat, dry heating methods for tender cuts (high temp, short cooking time), moist heating method for less tender cuts w/ high collagen content (low temp, long cooking time)

Question 28

What causes the cracks in meat when cooked?

Answer 28

protein coagulation

Question 29

purpose of curing meat?

Answer 29

preserving meats (decreasing water content inhibits microbial growth) popular ingredients used to cure meat potassium/sodium nitrate and sodium chloride

Question 30

what happens during curing process?

Answer 30

decreased water content prevent microbial growth, nitrate converts to nitrite, and reacts with myoglobin to form the red color nitrosylmyoglobin (that can help with inhibit bacteria)