animal science mrs. rada. causes of the shift ◦ refrigerated rail cars and trucks ◦ high real...
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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