Animal ScienceMrs. Rada

Causes of the Shift◦ Refrigerated rail cars and trucks◦ High real estate values◦ Closer to livestock◦ Multi-species plants single species plant◦ Whole Carcasses Boxed beef

Prevent unfair or deceptive practices Continually updated

Packer/processor vs. slaughter-only

Expenses1200 lb steer @

$78/cwt1200 x .78 = $936Slaughter cost=$45Total: 936 + 45 =

$981Drop by-products: Drop credit:

$7.90/cwt

Income63% dressing percent1200 x .63 = 756 lb

car.$119/cwt or $1.19/lb756 x $1.19= $899.64Total Drop Credit: 1200 x .079 =

$94.80$899.64 + $94.80 =

$994.44

$994.44 - $981.00 =

Profit: $13.44/head

Where does all the money go?◦ Cost of Livestock=80%◦ Labor=9%◦ Other Operating expenses=10%◦ Net Income=1%

Purchase meat rather than livestock Higher profit margins that packers (5 to

15%) Sausage making, curing, etc.

Wholesalers/distributors Retailers

◦ 25% of store receipts are for meat, poultry and seafood

Restaurants◦ 50% of consumers’ food dollar

Humane Slaughter Act of 1978◦ Animal handling and stunning

Stunning Render unconscious, not kill Methods

Mechanical (cattle) Electrical (pigs) Chemical (CO2)-Europe for pigs

Sticking (exsanguination) Standard vs. Kosher vs. Halal

Kosher: Rabbi must certify and no stunning Halal: Muslim

Skinning Beef, lamb and sometimes pork Hide (pelt) puller

Hair removal (pork) Scalding Singer (burn off)

Eviscerate Gutting

Split Wash

Hot water, steam or organic chemical Chill

Carcass

Wholesale

Subprimals

Retail Cuts (grocery store)

Uniform Retail Meat Identity Standards (voluntary)◦ Species◦ Wholesale (primal) cut◦ Retail cut

IMPS (Institutional Meat Purchase Specifications)

Size◦ Beef: largest◦ Pork: intermediate◦ Lamb: smallest

Color of lean tissue◦ Beef: cherry-red◦ Pork: reddish-pink◦ Lamb: dark pink to light red

Highest value◦ Middle meats

Rib and loin Next highest value

◦ End meat Chuck, round, brisket, shank

Lowest value◦ Rough cuts

the edible flesh of mammals used for food

Poultry: the edible flesh of poultry used for food

Beef: the meat from mature bovines that are generally over 12 months of age.

Veal: the meat from very young calves, usually less than 3 months of age.

Mutton: the meat from mature ovine carcasses that fail to show a break joint on the front foreleg.

Lamb: meat from lambs or young sheep, up to about one year of age that shows a break joint in the foreleg.

Pork: meat associated with all ages of hog carcasses.

Chevon: meat from mature goats. Cabrito: meat from young goats.

Inspection for wholesomeness is mandatory and is paid for out of tax dollars.

stamped with a round purple mark if passed for wholeness

Food Safety and Inspection Service inspects all raw meat and poultry sold in interstate and foreign commerce, including imported products.

The Agency monitors meat and poultry products after they leave federally inspected plants.

for animals not covered under mandatory inspection (i.e., buffalo, rabbit, reindeer, elk, deer, antelope)

handled under the Agricultural Marketing Act

gives the Secretary of Agriculture the authority to take whatever steps are necessary to make the product marketable

must pay an hourly fee for the service

Grading for quality is voluntary, and the service is requested and paid for by meat and poultry producers/processors.

quality grades - for tenderness, juiciness, and flavor; and

yield grades - for the amount of usable lean meat on the carcass. ◦ There are eight quality grades for beef. ◦ Quality grades are based on the amount of

marbling (flecks of fat within the lean), color, and maturity.

Official: Prime, Choice, Select, Standard, Commercial, Utility, Cutter and Canner

Industry Uses: Prime, Top Choice, Choice, select and “no roll”

Determined by maturity (A, B, C, D, E) and Marbling (Devoid to Extremely Abundant)◦ Maturity

A, B = Young C, D, E = Old

Problems with USDA Beef Quality Grades◦ 1 in 10 carcasses is mis-graded◦ Marbling is a poor predictor of tenderness

Prime grade ◦ is produced from young, well-fed beef cattle◦ abundant marbling◦ generally sold in restaurants and hotels ◦ Prime roasts and steaks are excellent for dry-heat

cooking (i.e., roasting, broiling, and grilling).

Choice grade ◦ is high quality◦ less marbling than Prime

Select grade ◦ is very uniform in quality◦ normally leaner than the higher grades◦ It is fairly tender, but, because it has less

marbling, it may lack some of the juiciness and flavor of the higher grades

Standard and Commercial grades ◦ frequently are sold as ungraded or as "store

brand" meat. Utility, Cutter, and Canner grades

◦ are seldom, if ever, sold at retail but are used instead to make ground beef and processed products.

Cutability 1, 2, 3, 4, 5 Determined by hot carcass weight, fat

thickness, rib eye area, and percentage of kidney, pelvic, and heart fat (KPH)

Very accurate if accurately applied ◦ 1 out of 4 carcasses is mis-graded

Range from "1" to "5" indicate the amount of usable meat from a

carcass◦ Yield grade 1 is the highest grade and denotes

the greatest ratio of lean to fat ◦ yield grade 5 is the lowest yield ratio

Yield grade is most useful when purchasing a side or carcass of beef for the freezer.

USDA Grades are not used Most pork packers use instrument

assessment of percent lean (% muscle)◦ Fat-O-Meat’er or Ultrasound◦ Measures fat depth and loin eye area

Quality is monitored by:◦ pH◦ Instrumental color

Higher number = darker color

There are five grades for Veal/Calf: prime, choice, good, standard, and utility.

Prime and choice grades are juicier and more flavorful than the lower grades.

Because of the young age of the animals, the meat will be a light grayish-pink to light pink, fairly firm and velvety.

The bones are small, soft, and quite red.

There are five grades for lamb. Normally only two grades are found at the

retail level – prime and choice◦ Prime grade

is very high in tenderness, juiciness, and flavor. Its marbling enhances both flavor and juiciness.

◦ Choice grade has slightly less marbling than prime, but still is of very

high quality.

Lamb is produced from animals less than a year old. ◦ Since the quality of lamb varies according to the

age of the animal, it is advisable to buy lamb that has been USDA graded.

Enjoyment of a meat eating experience is largely dependent on how it is cooked.

Color changes during heating◦ Very rare=130 Degrees F◦ Rare=140 Degrees F◦ Medium rare=150 Degrees F◦ Medium=160 Degrees F◦ Well done=170 Degrees F◦ Very well done=180 Degrees F

Muscle Fibers◦ Gradually shrink

Collagen fibers◦ Buckle

Tenderness◦ Little change

Juiciness◦ Slight Water Loss

Flavor◦ Changes (some

flavors become more intense)

Micro-organisms◦ Active

Muscle Fibers◦ Rapidly shrink

Collagen fibers◦ Begins to solubilize

Tenderness◦ Decreases in low

collagen cuts; increases in high collagen cuts

Juiciness◦ Water Loss

Flavor◦ Changes (some

flavors become more intense)

Micro-organisms◦ Trichinella Spiralis

Destroyed at 137 degrees F

Muscle Fibers◦ Harden

Collagen fibers◦ Continued solubilization

(if moist heat) Tenderness

◦ Decreases rapidly, rapid toughening; Tenderization continues in high collagen cuts (using moist heat)

Juiciness◦ Rapid loss of juiciness

Flavor◦ Changes (some flavors

become more intense) Micro-organisms

◦ 149 degrees F for 12-15 minutes destroys pathogens

◦ Convection Circulating air or water

◦ Conduction Heat passed between molecules

◦ Radiation Radiant waves

◦ Conventional range Oven-convection and radiation Stove-conduction

◦ Forced air convection oven Faster cooking

◦ Impingement oven High pressure air or water Very fast cooking

◦ Microwave oven No browning of meat surface

◦ Frying pan◦ Kettle, crock pot, Dutch oven◦ Grill◦ Continuous flow ovens

Dry-Heat Methods◦ Broiling

Meat directly exposed to heat source Steaks and chops

◦ Panfrying Thin cuts of meat, ground meat

◦ Stir Frying◦ Deep fat frying

Only for very tender meat cuts◦ Roasting

Uncovered, no water added Larger, more tender cuts

Moist heat-methods◦ Braising

Liquid is added Less tender cuts

◦ Cooking in liquid Stewing or simmering

Palatability of meat◦ Tenderness

Greatest animal-to-animal variation◦ Juiciness◦ Flavor

Juiciness◦ Degree-of-doneness◦ Fat content (marbling)◦ WHC (pH and rate of decline)

Flavor◦ Preparation

Cooking method and degree-of-doneness◦ Animal Age◦ Animal Diet◦ Fat content (marbling)

Inadequate Tenderness◦ #2 concern of beef retailers and restaurateurs

Two factors in tenderness◦ Connective tissue factors

Muscles differ in amount of connective tissue Older animal = increase collagen cross-linking =

decrease collagen solubility

◦ Myofibrillar factors Sarcomere length (ex. Cold shortening)

Shorter sarcomere length results in tougher meat Postmortem protein degradation

Dry aging vs. wet agin Majority of tenderization occurs within first 7 days

postmortem Cytoskeletal (structural) proteins are degraded (broken

down)

USDA Quality Grades◦ Official: Prime, Choice, Select, Standard,

Commercial, Utility, Cutter, Canner◦ Industry Uses: Prime, Top Choice, Choice,

Select, “no roll”◦ Determined by maturity (A, B, C, D, E) and

marbling (devoid to extremely abundant) Maturity:

A, B=Young C, D, E=Old (Hardbone)

◦ Problems with USDA beef quality grades 1 in 10 carcasses is mis-graded Marbling is a poor predictor of tenderness

USDA Yield Grades

Need microscope to see Food borne microorganisms Intoxication or infection

◦ Intoxication Microorganism produced toxin on food Ingested toxin causes sickness

◦ Infection Live organism is ingested and grows inside host

Produces toxin inside host

Bacteria◦ Most predominant

1 tsp. soil – 2 billion bacteria Human body – 100 trillion (outnumber cells 10 to 1)

Molds and Yeast (fungi)◦ Minor importance in meat

Molds like lower water activity Yeasts need sugar

Viruses◦ Usually not a problem in meat

Except raw shellfish Parasites

◦ Trichinella spiralis (Trichina) Causes trichinosis Pork Cook to 144 degrees F, freezing, curing to kill Very rare in US Feeding garbage to hogs

High in moisture Rich in nitrogenous foods Minerals and accessory growth factors Fairly favorable pH

Temperature◦ Mismanagement of temperature is #1 cause of

foodborne disease◦ Most organisms grow best between 40 and 140

degees F Keep meat hot or cold USDA recommends cooking ground meat at 160

degrees◦ Muscle interior is considered sterile

Time◦ Temperature-time relationship is most critical

aspect of food safety◦ Meat should pass between 40 and 140 degrees in

four hours or less Moisture

Oxygen pH

◦ Most organisms grow slower at ph above 5.0 Competing organisms

Vast majority of bacteria are not harmful Pathogens

◦ Bacteria that could potentially cause human illness Usually requires a large number to make you sick

◦ Examples Salmonella

2 million illnesses 200-1000 deaths annually

Escherichia coli (most strains are harmless) E. Coli 0157:H7

.025 Million illnesses 100-200 deaths annually Can be fatal to children

Pesticides and other chemical residues◦ 99.99% of pesticides in human diet are natural◦ Smith et al., 1992

Tested beef for 25 pesticides, 500 tests – 0 violative No difference between “organic,” “natural,” and

conventional beef◦ Risk of illness

1 in 1,000,000

Antibiotics◦ Residue in human food is not a problem◦ Infectious multiple-antibiotic resistance transfer

Create resistant strains of bacteria Potential problems

◦ Anabolic steroids/hormones Growth promotant 58% more estrogen in implanted beef

1.2 ng estrogen in non-implanted beef 1.9 ng estrogen in implanted beef

Daily production of estrogen by human body Men: 136,000 ng Women: 1,000,000 ng