MUSCLE TISSUE
Skeletal- provides support locomotion; primary component of carcass; attached to bone
Cardiac and skeletal – striated muscles Smooth muscle: visceral muscle, digestive
system, reproductive system Protein – 15-20%, high biological value
MUSCLE CELL MEMBRANE MYOFIBRILS - alternating thick and thin
protein filaments, contractile muscles Small bundles (20-40 fibers) - 1 primary
bundle represents grain Primary bundle surrounded by connective
tissue Several primary bundles for larger secondary
bundle with blood vessels and nerves
COLLAGEN Primarily protein Flexible non-elastic fibers White or colorless Contracts to thick mass when heated More tender - cook with moist heat Some hydrolyzed to water soluble gelatin Older animals - collagen coil less
solubilization due to cross-linkages
ELASTIN
Lesser component More elastic than collagen Holds bone and cartilage together Not softened to gelatin Yellow color
FATTY TISSUE Energy storage Dependent on animal feed, hormones, age, genetics,
breed, biological state, nutritional status, part of carcass cut is from
Percent increases with age Deposited around organs, under skin, between and
within muscles Held by strands of connective tissue Melted contributes to juiciness sensation of
tenderness and flavor
TYPES OF FATTY TISSUE
Adipose tissue -around heart, kidney Suet - hard fatty tissue around organs, more
saturated Subcutaneous fat - under skin, more unsaturated Intermuscular fat - between muscles (seam fat) Intramuscular fat - within muscles (marbling) Mainly triglycerides Fat – 5-40% (lean 7-10%)
WATER 45-75% (lean = higher water content) Decreases with maturity and increased fat In muscle fiber - less in connective tissue Decreases when muscle fibers broken due
to chemical, mechanical, enzymatic tenderization or salting, or change in pH
Curing increases water content Protein releases water as it coagulates
VITAMINS AND MINERALS
Vitamin B complex - no Vitamin C Fat soluble in liver low in A & D in red
meat Iron in heme and myoglobin pigments Zinc and phosphorus in muscle, some
copper
MUSCLE CONTRACTION
Contractile proteins - actin (in thin filaments) and myosin (in thick filaments)
Form actomyosin cross-links Overlap of thick and thin filaments Few overlaps = tender meat Many overlaps = tough meat
MORE TENDER MEAT Minimize cross-links by hanging carcass Control pre-rigor temperature Natural aging or conditioning - hang in 34-
38F for 1-4 weeks Higher temperatures used but increases
growth of bacteria - use ultraviolet light to reduce
Proteases added to break down cross-links
BONE SHAPE
Round hollow bone (leg) – less tender Flat, blade shaped bone – less tender T-bone shape – tender
CONNECTIVE TISSUE
Higher amount of connective tissue less tender the meat
Least used muscles have less collagen (rib and loin)
Age increases cross-linkages less tender
PIGMENTS MYOGLOBIN - holds O2 in muscle Primary pigment in meat Increases with age, level of muscle exercise Varies with species, sex, and muscle Oxymyoglobin - myoglobin exposed to O2;
bright red Metmyoglobin - oxidation of iron molecule =
brownish red color HEMOGLOBIN - transport O2 and CO2
COLOR
Indicates Freshness Amount of iron Kind, species Age of animal at slaughter Doneness after cooking Curing
USDA FOOD SAFETY AND INSPECTION SERVICE (FSIS)
MANDATORY Inspected and passed Safe to eat and without adulteration Exam of carcass and viscera did not
indicate presence of disease – sight, touch, smell
Not meant to imply freedom from all disease causing microorganisms
Inspection of processing plants
SAFETY REGULATIONS
Plants have HACCP plan SOPs for written sanitation requirements Tests for salmonella on raw meat and
poultry products Slaughter plants test for E.coli O157:H7 on
carcasses
SAFE HANDLING INSTRUCTIONS
For beef and poultry Raw or partially cooked food 1994 from USDA Decrease risk of foodborne illness Mandated for products and labeled in
USDA or state inspected processing plants and at retail stores
GRADING OF MEAT
VOLUNTARY PROGRAM -Indicates quality and yield
Evaluation of marbling, maturity, texture, appearance
Prime - very well marbled Yield - Boneless yield (1-5 Best to worst) Different for type of meat (beef, veal, lamb,
mutton)
SAFETY ALL meat contains bacteria Approval of steam pasteurization to
decrease risk of E. coli High intensity pulsed light Irradiation - approved for pork to destroy
Trichinella Hormones - to promote &/or increase lean
muscle, decrease fat
SAFETY Hormones - to promote &/or increase lean
muscle, decrease fat Must be discontinued for specified period of
time prior to slaughter Random samples by FDA to monitor Antibodies - treat existing disease, prevent
disease, promote growth Subtherapeutic doses - 1989 National
Academy of Sciences
CUTS OF MEAT
PRIMAL OR WHOLESALE SUBPRIMAL - boneless cut from primal RETAIL - cut from either Most tender = Rib, short loin, sirloin Medium tender = Chuck, round Least tender = flank, brisket, foreshank,
short plate, tip
ALTERATIONS
Meat changed by mechanical, chemical, or enzymatic treatment altering the taste, appearance, and keeping quality of the product
RESTRUCTURED MEAT
Flaked, ground, chunked Reformed Shaped Salts, phosphates, nonmeat binders added to
hold protein particles together
CURING OR SMOKING
Increases shelf life Forms pink color Produces salty flavor Contains nitrite – control growth of
Clostridium Botulinum Smoking – heat processed, dehydrates for
microbial growth
EFFECT
Peptides denature, reunite to coagulate releases water and melted fat Muscle fibers tighten Connective tissues become more tender
TENDER CUTS
Small amount of connective tissue Cook short time at high temperature Dry heat Longer at lower temperature
LESS TENDER CUTS
Prolonged cooking methods Will depend on amount of collagen, method
of cooking, cooking time and temperature
COOKING METHODS
DRY HEAT- broiling, frying, pan frying, roasting, stir-fry
MOIST HEAT - reduces surface drying, allows collagen to become gelatin
Braising, pressure cooking, stewing, steaming, cover with water
ARTIFICIAL TENDERIZERS MECHANICAL - cuts muscle fibers and
connective tissue Electrical - ultrasonic vibrations stimulate
muscle to breakdown ATP to Lactic Acid and decrease pH
Natural enzymes - from tropical plants Papain - papaya Bromelain- pineapple Ficin - figs Acid marinades
COMPOSITION AND STRUCTURE
Comparable to beef, lamb, pork Good source of iron, phosphorus, B vitamins Dark meat: more iron, zinc, riboflavin
more fat, connective tissue, myoglobin
less protein Light meat richer in niacin Chicken/turkey breast lower in cholesterol and fat Fat content increases with age
USDA FOOD SAFETY AND INSPECTION SERVICE (FSIS)
Wholesome Poultry Act of 1968 Mandatory Sanitary processing and freedom from
disease Operate with HACCP
LABEL
1997 labeling rule Defines terms fresh and frozen Hard chilled 2002 label percent of absorbed or retained
water Nutrition labels required either as posters,
brochures, or labels
COOKING Young, tender birds - same methods as
tender cuts of beef Frying for young, tender poultry Roasting for older bird Microwave not recommended due to
uneven distribution of microwaves and nonuniform response of chicken
Spoils readily - not aged, high salmonella
FLAVOR
Volatile carbonyls - aroma of cooked poultry
Sulfur compounds give meaty-brothy taste Fresh - better taste and higher aroma than
reheated or after frozen storage Yield - varies by age usually 1# = 2 servings
FIN FISH
Fat content <5%: Bass Flounder Halibut Perch Sole
Fat content 5-20% Albacore Herring Mackeral Salmon Shad Sardines Smelt Tuna
SHELLFISH
Skeleton - hard shell on the outside Invertebrate Crustaceans - segmented armor: crabs,
crayfish, lobster, prawn, shrimp Mollusks - Soft unsegmented body -
calcified shell: abalone, clams, mussels, oysters, scallops, octopus, squid, periwinkle, snail
COMPOSITION Excellent source of protein-quality and
quantity equivalent to meat Shellfish slightly sweet due to glycogen Saltwater fish - iodine Excellent source of phosphorus Low in iron, calcium (except for salmon
with bones) Fish with vertebrae low in B vitamins
CUTS
Steaks cut perpendicular to backbone Fillets cut parallel to backbone Whole Drawn Dressed Sticks Butterfly
INSPECTION
FDA Office of Seafood Required to follow HACCP system since
1997 For processors, repackers, and warehouses
– not retailers Standards for contaminants FDA administers National Shellfish
Sanitation Program
GRADING
US Dept. of Commerce – National Oceanic Atmospheric Administration
Quality grades – US Grade A, US Grade B, substandard
Appearance, uniformity, absence of defects character, flavor, odor
Breaded items – proportion of edible fish to breading and presence of bone
SAFETY Spoilage occurs rapidly due to powerful
digestive enzymes, fat content, composition Marine toxins - scrombroid poisoning and
ciguatera Rarely botulism Oysters pathogens from water with
untreated sewage Parasites killed with cooking
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