What factors affect meat quaility

tenderness

juiciness

flavor

color

odor

What factors affect meat palatability

tenderness

juiciness

flavor (taste and aroma)

palatability

consumers' perceptions of meat palatability are based on combined assessments of sensory attributes

Tenderness

Essential for consumer acceptance

Percentage of variation in tenderness with marbing

10%

Percentage of steaks considered tender

90%

What attribute is equally important to tenderness

flavor

Tenderness does what to the value of meat?

Increased tenderness is increased value

Postmortem Tenderization

Enzymes are responsible (calpains)

Attributes of calpains

activated by calcium

inhibited by calpastatin

degrade structural proteins (desmin, titin, nubulin)

What influences tenderness

sarcomere length

enzymatic degradation of proteins

connective tissues

Marbling

helps lubricate the mouth and reduce density

What percentage of marbling is needed for acceptabletenderness

2%

Halo Effect

gives the perception of more tender because of the sensation of juiciness

What enhances tenderness

Postmortem aging

physical tenderness

deep basting or enhancement

Post mortem aging

occurs regardless of human involvement

controlled degradation of meat proteins to increase tenderness

naturally occurring enzymes are released to degrade muscle structure

changes flavor and tenderness

Proteolytic Enzymes

Bromelain extracted from pineapple

can cause mushy texture if products are held at high temperatures for long periods

flavor is a combination of what

taste and aroma

taste

perceived by taste buds primarily on the tongue

Odor/aroma

greatest contributor to perceived flavor

low molecular weight volatile compounds bind to olfactory receptors and are responsible for perceived flavors

What are the basic tastes of meat

sweet

sour

bitter

salty

umami

Sweet

naturally occurring sugars, amino acids, and organic acids

sour

amino acids and organic acids

bitter

hypoxanthine

anserine

carnosine

amino acids

salty

inorganic salts and sodium salts

umami

glutamatic acid and salts as wells as nucleotides

Maillard reaction

combines amines and sigars to produce a meaty flavor

Intramuscular lipids

produced during cooking as a primary contributors to the flavor and aroma of meat

What does dark cutting disease taste like

blood/serum like

sour

bitter

soapy

What does PSE taste like

acidic taste

What factors affect flavor

species

breed

sex

diet

age

packing

fat amount and type

muscle

aging

enhancement

cooking method

What processes deteriorate meat quality

cacterial

chemical

enzymatic

physical

What helps maintain meat quality

shelf life

Importance of meat color

perceived quality

indicator of freshness or wholesomeness

affects meat purchase

determines retail case life

How is meat color measured

CIE L

CIE a

CIE b

CIE L

Lightness (z axis)

0-100

black to white

CIE a

redness (x axis)

-60-60

greater is more red

CIE b

yellowness (y axis)

-60-60

greater is more yellow

Hue

Trueness of red (b/a)

Chroma

intensity or degree of color saturation

Pythagorean theorem

What protein is responsible for meat color

Myoglobin

Non-protein portion

heme ring

Protein portion

globin

6th binding site of heme ring

chemical state of iron determines meat color

Chemical forms of myoglobin

Deoxymyoglobin

oxymyoglobin

metmyoglobin

carboxymyoglobin

deoxymyoglobin

no ligand for 6th binding site

heme iron is ferrous

purplish red/pink color

little to no oxygen

oxymyoglobin

O2 binds to 6th binding site

heme iron is ferrous

cherry red color

continuous exposure to O2

Metmyoglobin

oxidation of ferrous to ferric

brown/tan color

not enough oxygen after already exposed

Metpyoglobin reduction

oxymyoglobin to metmyoglobin

metmyoglobin to deoxymyoglobin

varies by muscle, postmortem age, pH, temperature

carboxymyoglobin

deoxymyoglobin exposed to carbon monoxide

heme iron is ferrous

red color

Chill rate

Temperature at which muscle enters rigor affects color

non-uniformity in muscle color due to pH/temperature decline

Iridescence

Rainbow of color

Poultry Quality Defects

white striping

spaghetti meat

woody breast

green muscle disease

Green muscle disease

Deep pectoralis muscle myopathy

isochemic necrosis in the deep pectoralis muscle

muscle fibers are replaced with adipose tissue and the color changes

white striping

white striations following the same direction of muscle fibers

accumulation of lipids of connective tissues

high cook loss

Spaghetti meat

impaired integrity of pectoralis major muscle

meat resembling spaghetti appearance

muscle fibers disintegrate

Woody breast

hardened area firm to the touch

crunchy texture

drip loss and cook loss

safe to eat but texture is off

hard to identify