The Meat We Eat Exam 2

What factors affect dressing percentage in lambs?

Fill, finish, fleece, sex, and muscling

what is the normal range for dressing percentage for sheep

44-56

Extensive Management Systems

Southwestern Range Operations• Utilize fine wool Rambouillet ewes and Hampshire orSuffolk Rams with very little supplementation

Majority of operations
Hands off

Extensive Management Systems

Northwestern Range Operations• Very similar to Southwest only more availability offeed• Often graze federal lands managed by the ForestService and the Bureau of Land Management

Intensive Management Systems

Farm Flock Operations• Common in the Midwest• Smaller in size and represents very small part of U.S. sheep production• Breeding stock and show lambs are produced

show operations
a lot of management

Intensive Management Systems

Lamb Feedlot Industry• Intensively managed system where lambs are fed high concentratediets• All of the consumed feed is harvested and brought to the lamb• Colorado and Texas are the leading lamb feeding states.

Katahdin

Developed in the 1950's on thePiel farm in Maine
• Crossing of hair sheep from theCaribbean with various Britishbreeds, especially the Suffolk
• Blends the best qualities ofCaribbean hair sheep with thesuperior growth and carcassquality of wooled sheep
• Excel in maternal and fitnesstraits, including parasiteresistance
• Most numerous registeredbreed of sheep in the US

which sheep breed is popular in research?

Katahdin

live weight- sheep

Most lambs are marketed between 105 and 130 pounds
• Avg = 125lbs

What is the normal range of dressing percentage for shorn lambs?

an average of 54

What is the normal range of dressing percentage for unshorn lambs?

an average of 52

Fat thickness

Measured at the 12th rib, it is the single factor used in yield grading ribbed lambcarcasses

fat thickness

The normal range is 0.05-.5 inches with an average of .25

Body wall thickness

The measurement taken approximately 4.5 inches form the midline of the ribbed lambcarcass. A lot of variation exists for this measurement based mostly off of age, breed andweight.

body wall thickness

The normal range is between 0.6 and 1.25 inches

rib eye area

The cross-section of the longissimus dorsi muscle between the 12th and 13th rib

what is the Normal range for rib eye area

The normal range is 1.5-3.5 square inches with an average of 2.3

rib eye area

highly correlated to weight
A 125-pound lamb has around a 2.5 square inch rib eye.

Break joints,
rib shape- mod narrow
lean color-slightly pink,
lean texture- fine

lamb

break or 1 spool,
rib shape- mod wide; flat,
lean color-slightly dark red,
lean texture- slightly coarse

yearling mutton

2 spool joints
rib shape- wide and flat
lean color-dark red
lean texture-course

mutton

what do lamb quality grades predict?

palpability

A preliminary grade is determined based on

maturity, flank streakings, and flank firmness

The preliminary grade and conformation score are then used to determine

the final quality grade

4 factors of quality grade

• Maturity
• Flank streakings
• Flank firmness
• Confirmation

what does lamb yield grades predict?

cut-ability

yield grade equation

0.4 + (10 X fat thickness,in)

what is one factor that impacts yield grade for lambs?

fat thickness

95-98 percent of lamb is

prime or choice

what are the three sectors of goat production

hair, meat, and dairy

what is produced by the Angora and is a long, lustrous fiber that is noted for durability and briliant color when dyed

mohair

goat pro facts

There is no grading system for meat goats, so there is agreater inconsistency in palatability and quality of theproduct.

goat pro facts

Boer Goat has played a vital role in improving goatproductivity and carcass characteristics

SouthAfrican Boer Goat

A hardy, fast growingmeat-type goat

• Medium size withprominent horns andbroad, drooping ears

• Generally brown head and neck with white body and legs, having short to medium hair

• Good meat type conformation with superior spring of rib,body length, and muscling

within 24 hrs after death

glycogen--> lactic acid
via anaerobic glyolosis

what is the muscle ph within 24 hrs after death

7.4 --> 5.6
Lactic acid build up
• Rate of lactic acid build up in impacted by the glycogen levels in the muscle at death and postmortem temperature

what is the muscle color during postmortem changes

purple --> bright red or pink

What is the ideal Postmortem pH decline?

gradual decrease from 7.4 to 5.6 or 5.7

What is the high Postmortem pH decline?

pH slowly declines and remains stable around 6.0 to 6.5

what is the outcome of a high pH decline

- Dark cutters or Dark, Firm and Dry

What is the low Postmortem pH decline?

pH drops rapidly to 5.4 or5.5 and then ultimately drops to 5.1 or 5.3

what is the outcome of a low ph decline

- pale soft and exudative

postmortem

The drop in postmortem pH also affects thewater holding capacity (WHC) of meat.

What is Water Holding capacity? (WHC)

WHC is the ability of a muscle to retain water duringcutting, heating, grinding, etc.

pH Impact on Water Holding Capacity

Water-holding capacity is the lowest is the isoelectric point (pH ~ 5.1)
• The number of positively and negatively charged groups of the myofibrillar proteins is equal
• The charges cancel out and no charge is available to hold the bound and immobilized water

Long Term Stress

Long-term glycogen depletion or glycogen deficiency at the time of slaughter
• High pH
• Dark color
• High water holding capacity
• Firm lean texture

Long Term Stress

Physiological response to stress

What are the types of stress?

Temperature
• Sound
• Space
• Handling
• Transportation
• Sickness
• Exhaustion

DFD beef (Dark Cutters

caused by long term glycogen depletion as a response to "alarm"
a) Glycogen is converted to lactic acid and pyruvic acid inorder to generate more ATP; initiated by adrenaline

factors for DFD beef

exhaustion, exposure to cold, excitement,feed withdrawal, sickness

how to prevent DFD

Stress prevention and proper handling are best solutions

short term stress

High levels of lactic acid in muscle at time of slaughter• Rapid decline in pH

short term stress

Low pH
• Pale color
• Loss of water holding capacity
• Decreased processing yield
• Increase cook loss
• Decreased juiciness

Short Term Stress

Less than 6 hours prior toharvest

short term stress

Typically in pork
• Short-term glycogen depletion -hereditary
• Porcine Stress Syndrome
• Extreme muscularity
• Anxious behavior
• Muscle tremors
• Redding of skin

Pale, Soft, and Exudative (PSE) Pork

Results from short-term glycogen depletion

Pale, Soft, and Exudative (PSE) Pork

Caused by swine susceptibility to PSS and toexcitementa) Antemortem: rapid glycolysis due to excitementb) Postmortem: too long on kill floor accelerates glycolysiswhile carcass temperature is high

Pale, Soft, and Exudative (PSE) Pork

pH of muscle reaches 5.2 within 2 h4. Solution: decrease emphasis on heavy muscle;• rest prior to slaughter and handle properl

ph impact- normal

Muscle color- normal
Glycogen at death- 1.0%
Glycogen at 24 hr- 0.1%
Lactate production- high
Ultimate muscle pH-5.6

ph impact-dark

Muscle color-dark
Glycogen at death- 0.3%
Glycogen at 24 hr-0.1%
Lactate production- low
Ultimate muscle pH- 6.0 to 6.5

ph impact- pale

Muscle color-pale
Glycogen at death- 0.6
Glycogen at 24 hr-0.1
Lactate production- very high
Ultimate muscle pH- 5.1- 5.3

what is rigor mortis

stiffness of death

what stage is rigor mortis complete?

stage 3
100% rigor

what are the phases of rigor mortis

1. Delay phase
2. Onset phase
3. Completion phase
4. Resolution

taste and eating satisfaction

Tenderness
Juiciness
Flavor
Appearance
Aroma
Freshness

what is the goal for taste and eating satisfaction

Best possible eating experience each time a consumer chooses meat

why is tenderness the most studied?

Accounts for ~ 80% of consumer's overall acceptability
• Varies far more than flavor and juiciness
• Flavor and juiciness can be influenced by cooking method and seasonings

Warner-Bratzler Shear Force (objective)

Pounds of force to shear one-half-inch cores, removed parallel to the muscled fibers of cooked muscles from steaks and roasts

Slice Shear Force (objective)

Pounds of force to shear the lateral end of each steak a 1-cm-thick, 5-cm-long slice that is parallel to the muscle fibers

SENSORY TESTING (subjective )

Sensory Testing Environment
• Trained vs Consumer Panel setting

reasons for cooking meat

Food Safety
• Improve Palatability
•Aroma• Flavor

what does cooking meat impact?

tenderness and juiciness

dry heat

Roasting
• Broiling
• Grilling
• Pan Broiling
• Griddle
• Deep-fat frying
• Stir-frying
• Air frying

moist heat

Braising
• Cooking in liquid
• Boiling
• Simmering
• Stewing

what is the most popular in the meat industry wet or dry aging?

wet

what are the two types of cut for tenderness

High collagen
• Low collagen

tenderness

Increase Degree of Doneness
• Reduce muscle fiber tenderness
• Gelatinize collagen

what impacts juiciness

marbling

juiciness

Ultimate pH impacts water holding capacity• Dry Heat• Less Juicy when cooked for extended time• Moist Heat

in terms of flavor what is impacted by animals

marbling
finishing ration

in terms of flavor what is impacted by the industry

Chill time
• Tenderization

in terms of flavor what is impacted by the chief

Salt
• Pepper
Marinades

beef flavor development

Rich beef flavor moves front to back (follows fat)
• Chuck & Rib = very rich beef flavor
• Loin and Sirloin = moderate beef flavor
• Round = mild beef flavor

what are the odds of a bad eating experience for Prime

3% (1 in 33)

what are the odds of a bad eating experience for upper 2/3 choice

10 % ( 1 in 10)

what are the odds of a bad eating experience for choice

16% (1 in 6)

what are the odds of a bad eating experience for select

27% (1 in 4)

what are the odds of a bad eating experience for standard

50% (1 in 2)

what is the oldest method of tenderizing

grinding

What meat quality issue results from short-term glycogen depletion?

pse

What factor does not impact Palatability?

hot carcass weight

What is the ideal fat thickness of a market lamb?

0.25

Which of the following species has the fastest onset of rigor?

pork

What is the ideal pH of meat?

5.6

What type of meat quality issue results form short-term glycogen depletion and causes meat to have the lowest water holding capacity?

pse

What is the safe end point cooking temperature for ground beef?

160

wet vs dry

safe end point