Meat & Poultry

Meat

Refers to the flesh/muscles of animals used as food o Internal organs are considered also as meat

• Common animals: cattle, sheep, pig, poultry

• Philippines: carabao, goat

o East Africa: gazelle (African dear), zebra meat

• North America: Buffalo

o Arctic: polar bears, seals, whales

• red meats

• white meat - fish and poultry

Poultry

Refers to several kinds of domesticated fowl used as food

Wild fowls (game), chicken, duck, goose, turkey, pigeons, quail, ratite family

• Ratite: ostrich, emu (Australian bird), rhea

broiler,fryer,roaster,stewers,capon,rooster

TYPES OF CHICKEN

broiler

chicken that is 7-12 weeks, very tender with 5% fat

fryer

14-20 weeks chicken

roaster

3-5 months chicken

stewers

10 mos-1 year; mature females, high fat

capon

castrated, 4 mos; very tender chicken

rooster

mature male chicken less tender, more flavor, 10 mos

duckling,duck,peking duck

types of ducks

young tom, tom turkey

Types of turkey

duckling

duck that is less than 8 weeks; very tender, highg fat

duck

duck that is mature, 6 mos , lacks fat

peking duck

a special breed; meat has a distinct flavor

young tom

a turkey that is roasting type, 16-30 weeks

tom turkey

a mature turkey

squabs

young immature pigeons, 4 weeks old

veal

meat from very young cattle, 3 weeks to 3 months of age

calf

3 months to 8 months cattle

beef

cattle from steers and heifers

steers

young male cattle up to 4 years old and may oftentimes

be castrated

heifers

cows that have not produced calves and are less than

3 years old

meat from older cows

sold as beef

pork

Meat derived from pigs

suckling pigs

less than a month old; used for lechon de leche

lechon

Pigs up to 6 months - used for ——

meats from sows (castrated meals)

used for processed meats

carabeef

Meat from carabao

chevon

meat from goat

lamb

meat from sheep less than 6 months

mutton

meat from older sheep

meat

• a high value food; high grade protein

filipinos

people who are more on pork and chicken

overconsumption of meat

• major culprit of lifestyle disease

local production

not sufficient for local consumption

NATIONAL MEAT INSPECTION SERVICES

NMIS

meat structure

Consists of 3 kinds of tissues: Muscular (lean), fatty connective tissues, bones

lean tissue,connective tissue, fats

meat structure consists of

lean tissue

consists of one or more muscles, each of which is made up of many bundles of muscle fibers, contain less amounts of connective tissue and fat, about 18% protein.

meat

ordered arrangement of groups of fibers in descending order, each component enclosed in a network of connective tissue sheaths

sheaths

not really strict enclosures since these structures penetrate the muscle bundles and fibers and converge eventually to attach the muscles to skeletal system

sarcolemma

• membranous sheathe enclosing each individual muscle fiber

sarcoplasm

• contains vitamins, enzymes, myoglobin and part of protein

endomysium

• very delicate tissue found between muscle fibers

perimysium

• connective tissue enveloping each individual muscle bundle (fasciculi)

epimysium

• connective tissue surrounding an entire muscle

myofibril

• Made up of alternating rows of myofilaments running parallel to the axis of the muscle fiber

myofilament

• composed of sarcomere

sarcomere

• composed of two filaments (contractile proteins)

thick actin and thin myosin

2 filaments of sarcomere

ATP,Ca,Mg

*when muscle contracts, the actin forms a complex with myosin forming actomyosin. (a myofibrilar protein formed by the union of actin and myosin during muscle contraction); formation of actomyosin and degradation to actin and myosin (during muscle relaxation) are catalyzed by ————

myofilaments actin and myosin

• for muscle contraction; roles in post-mortem changes and water-holding capacity of meat

sarcolemma

• o a delicate transparent membrane that encloses the muscle
  fibers

• Contains a jelly-like protein sol, the sarcoplasm

• Myofibrils are embedded in this sarcoplasmic protein matrix

sarcoplasm

sarcolemma Contains a jelly-like protein sol, the —-

myofibrils

• are embedded in this sarcoplasmic protein matrix

connective tissues

Surround the fibers and unite them in bundles, Merge into a large mass, the tendon at the termini of each muscle which is anchored to the skeleton

collagen, elastin, reticulin, ground substance

Four categories of protein and conjugated proteins in connective tisuves:

inside perimysium

• Veins/arteries/larger veins are found in

inside endomysium

• Capillaries/smaller nerves found in

collagen

thin, white, transparent

• When meat or poultry is cooked using moist-heat methods, collagen softens and turns to gelatin

elastin

very tough, yellowish

• Cannot be softened by heat
  o Tenderizing methods such as pounding, cutting, or grinding must be used to break down elastin

fat content affects tenderness

• More marbling=more tender

• Fat=flavor, keeps juicy as it cooks

collagen

• Are elongated proteins that form extremely strong but small fibrils which associate together to form collagen fibers which in turn form sheets or cables that can be easily distinguished in meat cuts

• Most abundant protein in animal body o Important in determining toughness in meat o Collagen changes as animal ages
  o Arranged in parallel fasion: is flexible; does no stretch: found in tendons; which attach muscles to the bones; color is white: disintegrates in hot water thus is softened in cooking; changes to gelatin during cooking

reticulin

• A type of collagen

• Associated with myristic acid

elastin

• Has true elastic properties compared to collagen which derives itfelosticity only when it forms into cable-like tendons

• Elastic properties in tissues of neck, abdominal/intestinal wall, arterial system

• Rubbery structure due to desmocine and isodesmosine o Resistant to heat, acid, alkali

o Locomotion muscles are tough cuts in meat

• More digestible in human gut (elastase from pancreas)

collagen

• 65°C: the helidal structure of collagen is disrupted, forming gelatin

o Tenderization of meat cuts with high connective tissue content

ground substance

gel of proteins and glycoproteins in which collagen and/or elastin are bound

fats

• Found around or between muscles, or in connective tissues, As insulation from cold, as energy stores

oleic,palmitic,stearic

3 fatty acids that composed fats

glycolipids,cholesterol,glycolipids,phospholipids

4 lipids that composed of fats

Amount of fat depends

• Age of animal: more fat w/ older animals

• Feed of animal: more fat from well fed animals

• Amount of exercise: more fat of exercise is limited

• Specie: pigs accumulate fat more readily than most other animals

anatomical location

refers to the part of anatomy where fat is located (Shoulders, belly, neck)

systemic location

refers to whether subcutaneous or under the skin, intermuscular or between muscles, intramuscular or within muscles, visceral or around guts

Too thick subcutaneous fat

undesirable fats

marbles fat

adds value to meat

marbling

The distribution of fat in connective tissues and within

muscles

• Wavy lines in the meat

o Marbling in meat- determines juiciness and tenderness;

fat prevents moisture loss during cooking

• Flavor of meat - associated w/ carbonyl compounds in adipose tissues

marbling in meat

determines juiciness and tenderness;

fat prevents moisture loss during cooking

flavor of meat

associated w/ carbonyl compounds in adipose tissues

pork

has higher fat content than all other meat sources

pre-rigor stage

Changes in cell metabolism and protein structure

ATP and creatinine phosphate

stored for muscle contraction of a living animal

pre-rigor stage

Upon death, ATP stores depleted, oxygen supply stopped, leading to anaerobic glycolysis & formation of lactic acid: fall of pH

lack of oxygen

decrease in temperature and concentration of calcium ions

Stress-free and relaxed slaughter

do not feed animal before slaughter to avoid a full gut that can be a source of contamination

Post-Mortem Changes in Meat

"After Slaughter"

o initial stage of bleeding: cardiac activity continues so that all blood is pumped out

o It is important of first stunning the animal to unconsciousness before killing

o lf impartial bleeding: leaves a lot of blood in vessels, may result to early spoilage

initial stage of bleeding

cardiac activity continues so that all blood is pumped out

if impartial bleeding

leaves a lot of blood in vessels, may result to early spoilage

immediately after death

muscle is pliant, soft, gel-like, extensive and sticky; best to cook at this stage

post-mortem changes in meat

Decrease in pH from 7-7.2 to pH 5.5 due to formation of lactic acid anaerobically from glycogen

rigor mortis

• temporary rigidity of the muscles after slaughter

• Formation of actomyosin

• loss of ATP
  Loss of extensibility with the formation of actomyosin proceeds slowly at first (slow period), then rapidly (fast period)

post mortem changes in meat

1. After a few days, if held at temperatures above freezing (called aging), there is gradual tenderization; rigidity of actin & myosin weakens; coagulation of muscle proteins occurs due to accumulation of acid and subsequent syneresis, meat softens; best time also to cook at this stage

2. Dark-cutting of beef (very dark, sticky beef) develops if final pH 6.6 is reached during aging period as the carcass passes through the rigor mortis

3. An abnormally low pH 5.1 or 5.4 during rigor mortis is reached resulting in pale, soft and exudative pork (PSE) where pork becomes ligh-colored, mushy w/ considerable drip loss during cooking

resolution of rigor

loss of biological regulation of proteinases

proteinases from muscles

hydrolyze mustle proteins, weakening the structure and promoting tenderness

chilling

desirable flavor development

cold shortening

subjected to rapid temperature change from 37°C
to 6-8°C; Avoid cold shortening by storing meat in no lower than 10°C
for at least 10 hours after slaughter, then after resolution of mortis, meat may be transferred to a safe chilling storage at 4°C or lower

low meat pH

low WHC and pale meat color = PSE

(pale, soft and exudative); metallic and off-flavor taste

high meat pH

causes dark meat color = DFD (dark, firm

and dry): shorter shelf life

low meat pH level

Pale color, soft texture, exudative

PSE (pale, soft, exudative), off-flavors, low WHC

high pH meat level

Dark color, firm texture

DFD (dark, firm, dry), shorter shelf life

reduction of pH

brought by ATP hydrolysis