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