Sdsu Meat Science Exam 3

Front 1

What is impermeable (anaerobic) packaging used for?

Back 1

Fresh or frozen meat

Front 2

Anaerobic packaging has a decreased potential for...?

Back 2

1. Bacterial growth (increases shelf life)

2. Oxidation

3. Freezer burn

Front 3

What are some examples of impermeable packaging?

Back 3

1. Vacuum packaging with polyester

2. Freezer paper

Front 4

What is Modified Atmosphere (MAP) used for?

Back 4

1. Fresh Meat

2. Long-term storage (Roughly 40 day)

Front 5

How does MAP affect meat?

Back 5

1. Increases quality

2. Decreases microbial growth

Front 6

What is the common mix for MAP?

Back 6

80% oxygen, 15% carbon dioxide, 5% nitrogen

Front 7

What happens as a result of slow freezing?

Back 7

1. Pure ice crystal formation (that damages cells)

2. Increases drip when thawed

3. Muscle fiber shrinkage

4. Concentration of salt and sugar

5. Creates a mushy texture

Front 8

What does IQF stand for? How does this process work?

Back 8

Individually Quick Frozen; Blast freezer with high velocity below 20 degrees. Has nitrogen, dry ice, and liquid immersion/spray.

Front 9

What happens as a result of fast freezing?

Back 9

1. Small ice crystal formation

2. Decreased drip loss when thawed

3. Reduces muscle fiber shrinkage

4. Stabilizes color

Front 10

What are the three methods of thawing?

Back 10

1. Cold air

2. Cold water

3. Cook it -- microwave

Front 11

What are the disadvantages of thawing?

Back 11

1. slow

2. does more damage than freezing does

3. forms new ice crystals

4. creates potential for microbial growth

5. challenges texture (DON'T REPEAT)

Front 12

At what temperature should you maintain your fridge at?

Back 12

33-37 degrees C

Front 13

How does refrigeration improve shelf life?

Back 13

1. slows growth of pathogenic and psychrophilic bacteria

2. slows reactions (both enzymatic and chemical)

Front 14

In what order should you organize your fridge from top to bottom to prevent cross-contamination?

Back 14

1. Ready to eat food

2. whole raw fish

3. whole raw meat

4. raw ground meat

5. raw poultry

Front 15

What are the four steps to food safety?

Back 15

1. clean

2. separate

3. cook

4. chill (don't leave at room temp for more than 2 hr)

Front 16

What are the major objectives of cookery?

Back 16

1. Safety -- kills bacteria

2. Improve palatability

Front 17

What is the reaction called that turns the red color to a brown color (myoglobin to metmyoglobin)?

Back 17

Maillard reaction

Front 18

What are the three types of connective tissue?

Back 18

1. collagen

2. elastin

3. reticulin

Front 19

What percentage of all protein does collagen make up?

Back 19

20-25%

Front 20

How are fat droplets created?

Back 20

Heat reconverts collagen to gelatin (gelatinization)

Front 21

What is fat translocation?

Back 21

Occurs when the temperature of muscle increases and collagen solubilizes and channels develop for melted fat to diffuse

Front 22

In what ways do we lose moisture from meat?

Back 22

1. evaporation

2. water holding capacity

3. subcutaneous fat

4. lipid translocation

Front 23

What are the 3 different types of heat transfer?

Back 23

1. conduction

2. convection

3. radiation

Front 24

What is conduction?

Back 24

particle-to-particle contact/direct heat;

grill

Front 25

What is convection?

Back 25

circulatory motion of heat/indirect heat;

oven

Front 26

What is radiation?

Back 26

energy through waves; microwave

Front 27

What are the 2 types of mass transfer?

Back 27

1. dry heat

2. moist heat

Front 28

What is moist heat?

Back 28

Meat surrounded by hot air

Front 29

What results from dry heat?

Back 29

1. improved flavor by crust formation and carmelization

2. can increase chewiness and decrease tenderness due to coagulation thus protein hardening

Front 30

What types of cuts should be sued for dry heat?

Back 30

Tender cuts; beef rib, loin, sirloin, rump, inside round (low in collagen and elastin)

Front 31

What are some examples of dry heat?

Back 31

Broil, roast, grill, fry

Front 32

What is moist heat?

Back 32

Makes use of hot liquids and steam (steam injection is included as well)

Front 33

What cuts are recommended when using moist heat?

Back 33

tough cuts -- roasts, shanks

Front 34

What are some examples of moist heat?

Back 34

braise, simmer, steam, sauteing, stewing, pressure cooker

Front 35

How long should you allow meat to rest after cooking to take temperature? How do you properly take the temperature of the meat?

Back 35

approximately 10 min; from the geometric center

Front 36

At what temp is meat considered very rare?

Back 36

130 F

Front 37

At what temp is meat considered rare?

Back 37

140 F

Front 38

At what temp is meat considered medium rare?

Back 38

145 F

Front 39

At what temp is meat considered medium?

Back 39

160 F

Front 40

At what temp is meat considered well done?

Back 40

170 F

Front 41

At what temp is meat considered to be very well done?

Back 41

180 F

Front 42

What influences a perfect steak?

Back 42

1. texture of meat

2. type of beef

3. temp of meat before cooking

4. thickness and volume of the piece

5. temperature

6. desired doneness

7. heat source

Front 43

What is the main component affecting meat color?

Back 43

chemical state of myoglobin

Front 44

What states are ferrous (Fe ++)

Back 44

1. deoxymyoglobin

2. oxymyoglobin

3. nitric oxide myoglobin

4. carboxymyoglobin

Front 45

What color is deoxymyoglobin?

Back 45

purple

Front 46

What color is oxymyoglobin?

Back 46

red

Front 47

What color is nitric oxide myoglobin? What do you add to to the oxymyoglobin to get this?

Back 47

unstable pink; nitric oxide

Front 48

What color is carboxymyoglobin? What additive causes this?

Back 48

red; carbon monoxide (CO)

Front 49

What chemical states are Ferric (Fe+++)?

Back 49

1. metmyoglobin

2. denatured metmyoglobin

3. sulfmyoglobin

4. choleglobin

Front 50

What color is metmyoglobin?

Back 50

brown

Front 51

What color is denatured metmyoglobin?

Back 51

brown/grey

Front 52

What color is sulmyoglobin? What additive is added to create it?

Back 52

green; SH

Front 53

What color is choleglobin? What additive is used to create it?

Back 53

green; H202

Front 54

How does pH affect meat color?

Back 54

Higher pH equals darker colors; lower pH equals lighter colors

Front 55

What is meat color dependent on (more specific than just myoglobin and its chemical state)?

Back 55

1. pigment content

2. ultimate pH and rate of pH decline PM

3. nature of group attached to iron and state of the iron

4. ingredients, processing, and packaging

Front 56

What are the two main pigments? What is the majority of color due to?

Back 56

Hemoglobin and Myoglobin; myoglobin

Front 57

What is the structure of myoglobin? What is its purpose?

Back 57

Globin protein attached to a prophyrin ring containing a heme iron (with either an ionic or covalent group attached to the iron); takes oxygen from hemoglobin and stores it for use by living muscle

Front 58

What are the 4 major chemical forms of myoglobin?

Back 58

deoxymyoglobin, carboxymyoglobin, metmyoglobin, oxymyoglobin

Front 59

Why is metmyoglobin formed from oxymyoglobin?

Back 59

Complete oxygen consumption from cellular respiration

Front 60

What are the four factors that affect meat color regarding the amt of myoglobin in the muscle?

Back 60

1. age (oldest has more)

2. species (pork (2) <lamb (6) <beef (8) )

3. type (support<locomotive)

4. red vs white muscle fibers

Front 61

How does feeding Vitamin E affect meat color?

Back 61

prevents oxidation; retards conversion of myoglobin to metmyoglobin

Front 62

How does bacteria affect meat color?

Back 62

produces metmyoglobin, choleglobin, and sulfmyoglobin pigments

Front 63

How does curing affect meat color?

Back 63

nitrosylhemochromagen is the stable cured meat pigment (pink)

Front 64

Feeding vitamin E increases the concentration of what antioxidant?

Back 64

alpha-tocopherol

Front 65

How does long-term and short-term stress affect color?

Back 65

Affects glycogen content of muscle and ultimate pH of muscle

Front 66

Long term stress causes what? What will be the ultimate pH be above in cattle and pork?

Back 66

Dark cutters; beef: 5.9; pork: 6.5

Front 67

What does short term stress cause? What is the ultimate pH below in pork? How can this problem be overcome?1

Back 67

PSE; 5.4; with enhancement

Front 68

What are the purposes of meat processing?

Back 68

1. preservation - OLD

2. flavor

3. nutrition

4. convenience - NEW

5. variety - NEW

6. add value

7. provide a market for live animals

Front 69

What percentage of the pork carcass can be cured? Examples?

Back 69

about 80%;

hams, bacons, picnics, pork hocks, jowls, loins, boston butts

Front 70

What is the most commonly sold cured beef item? Where did it get its name? What beef cut is used?

Back 70

corned beef; from the name "corn" given to the corn-sized rock salt used to cure the meat; brisket (sometimes beef rounds when brisket supply is short)

Front 71

At levels high enough to preserve, salt alone produces products that are:

Back 71

1. too salty

2. dry

3. harsh

4. undesirable in color

Front 72

What does salt extract from meat? What is the purpose of this?

Back 72

proteins; creates bind

Front 73

What can be used to replace salt? How much of the salt can it replace?

Back 73

KCl; 40%

Front 74

What is the main purpose of phosphates?

Back 74

it increases pH, thus increasing water holding capacity

Front 75

What percentage can phosphate not exceed in meat? What happens if it does?

Back 75

0.5%; gives soapy flavor

Front 76

What is the most common nitrite used?

Back 76

Sodium nitrite (NO2-)

Front 77

What is the function of nitrite?

Back 77

fixes color and inhibits bacteria and other pathogens

Front 78

What vegetable juice is most commonly used due to natural nitrate (NO3-) levels?

Back 78

celery juice

Front 79

What is the stable state of cooked cured meat?

Back 79

nitosohemochrome

Front 80

What are the concerns about nitrite?

Back 80

Is toxic! 1 kg is lethal and it relaxes smooth muscle and blood pressure. It also reacts with many things w/in the meat system and can be carcinogenic this way

Front 81

How does nitrosamine form?

Back 81

when a NO+ ion from nitrite reacts with an amine in acidic condition

Front 82

What is the FDA Delaney Clause?

Back 82

A provision in the "food additives amendment of 1958" that if a substance was found to cause cancer in a man or animal, then it could not be used as a food additive

Front 83

What does sodium erythorbate do?

Back 83

accelerates curing reaction

Front 84

What are the functions of sweeteners?

Back 84

1. flavor - counteracts harshness of salt

2. substrate for lactic acid bacteria - acid formation

3. some improve casing peeling

Front 85

What is the content of sweeteners limited to? by who? what level do most consumers prefer in hams?

Back 85

2%; USDA; 2%

Front 86

What are the different sweeteners that can be used?

Back 86

1. sucrose

2. dextrose or glucose (corn sugar)

3. corn syrup and corn syrup solids

4. sorbitol

5. honey

6. brown sugar

Front 87

What is the threshold for taste level for sucrose?

Back 87

0.5%

Front 88

What is the threshold for taste level for dextrose?

Back 88

0.6%

Front 89

What is the sweetness value of sucrose? What does it do?

Back 89

100%; it is a browning sugar --> maillard rxn

Front 90

What is the sweetness value of dextrose? what is it used as?

Back 90

70-80%; browning sugar - maillard rxn and in fermented sausage it creates lactic acid and in fresh sausage it creates color

Front 91

What is the sweetness value of corn syrup and solids? What is the benefit of it?

Back 91

40-50%; less expensive

Front 92

What is the sweetness value of sorbitol? what is different about it?

Back 92

60%; non-browning

Front 93

What does honey do? What is bad about it?

Back 93

creates different flavoring and product images; is expensive

Front 94

Why is brown sugar used? What are 2 negatives about it?

Back 94

it provides additional flavor with a sweetness between sorbitol and corn syrup; it is costly and it is difficult to manage dryness

Front 95

What does MSG stand for? What does it do?

Back 95

Monosodium glutamate; it is a flavor enhancer by reacting with umami receptors on tongue creating a more savory taste

Front 96

What are the major functional properties of protein?

Back 96

1. water holding capacity

2. fat stabilization

3. particle-to-particle binding ability

4. development of desirable color properties

Front 97

What are the factors that influence processing quality?

Back 97

1. Protein- water interaction
WHC and function of pH

2. fat quality

saturated and unsaturated

Front 98

What are the three types of water?

Back 98

1. bound

2. immobilized

3. free

Front 99

What influences WHC?

Back 99

Mainly the pH of the protein. When it is at its isoelectric point (5.2), it does not bind with water very well. Therefore, can add phosphates and salt to change pH (phosphate raises and salt extracts proteins)

Front 100

What proteins are the most important proteins in the binding of H20 in the meat? What are their net charge?

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Back 100

Myofibril proteins; net negative charge

Front 101

Describe saturated fat.

Back 101

has NO double bonds and is solid at room temperature. It is less subject to oxidation but at high levels it increases blood cholesterol and can cause heart disease if it is a long chain. Short chains have no affect on health.

Front 102

Describe unsaturated fat.

Back 102

Has one or more double bonds and has 2 forms - cis and trans. It is liquid and room temperature and is susceptible to oxidation = rancid flavors

Front 103

How do fish, pork & poultry, and beef & lamb compare in terms of unsaturated fat?

Back 103

Fish has highest concentration of unsaturated fat, pork and poultry have over 50% unsaturated fat, and beef and lamb have less than 50% unsaturated fat

Front 104

Why do beef and lamb have the least unsaturated fat?

Back 104

because the rumen synthesizes mostly saturated fats for deposit

Front 105

Does internal or external fat have the highest amount of saturated fat?

Back 105

Internal fat

Front 106

What three selections can be used to choose more unsaturated or saturated fat?

Back 106

1. species

2. location of fat

3. diet

Front 107

What is the pro and the con for feeding saturated fat?

Back 107

pro: better for processing quality

con: health risk and therefore less consumer appeal

Front 108

what is the pro and the con for feeding unsaturated fat?

Back 108

pro: better for health and therefore increased consumer appeal

con: poorer quality products

Front 109

What are meat emulsions?

Back 109

Fat dispersed in water with emulsifying agent molecules surround the fat or oil droplet. Created by grinding or chopping meat and water with the addition of nacl to a fine homogenate

Front 110

What bone is used in TAMU tenderstretch?

Back 110

Obturator foramen - pelvic bone

Front 111

What muscle is most improved by TAMU tenderstretch?

Back 111

semimembranosus

Front 112

Where is the TAMU tenderstretch used? Where is it not used?

Back 112

Australia; USA

Front 113

Where was the tendercut came up with?

Back 113

VA tech

Front 114

How does the tendercut happen? How does it improve the meat?

Back 114

Pre-rigor cut of the 12th thoracic vertebrae; increases sarcomere length of the LD by about 25%

Front 115

What is proteolysis?

Back 115

degradation of structural proteins

Front 116

What structural proteins are destroyed by proteolysis?

Back 116

titin, nebulin, and tropoin T

Front 117

How long after PM is connective tissue not effected?

Back 117

10 days

Front 118

What are the 4 theories of marbling?

Back 118

1. Bulk Density Effect - Tenderness

2. Lubrication Effect - Water

3. Insurance Theory - Moisture

4. Strain Theory - Weakens

Front 119

What is the heritability for marbling?

Back 119

0.40

Front 120

What ways can you measure palatability?

Back 120

1. Warner Bratzler Shear Force (Tenderness)

2. Cook Loss - Juiciness

3. Gas chromatography - Flavor

4. Sensory analysis

Front 121

How can you improve palatability via processing?

Back 121

1. mechanical tenderization - disrupt fibers

2. brine enhancement - water and salt

3. ingredients - add flavors

bromelain = pineapple

papaya = papain

Front 122

What are the 4 factors that effect tenderness?

Back 122

1. connective tissue

2. sarcomere length

3. proteolytic enzymes

4. adipose/marbling