Unit 13 - Beef Carcass Grading Flashcards
What are the two aspects evaluated during carcass grading?
yield grade - evaluates how much meat can be produced from a carcass
quality grade - predicts how good the quality of the meat produced is
What is the main purpose of carcass grading?
group carcasses based on the quality of the saleable meat yield
What are the two benefits to carcass grading?
producers - bonus payments based on carcass merit. help them on decision-making at the production level
meat industry - increases consistency, allows a marketing strategy, possibility to be more specific on market demand
What is the difference between grading and inspection?
grading:
- not mandatory
- measures amount (yield) and quality of meat produced
inspection:
- mandatory
- ensures the safety of the saleable meat
What are three major factors affecting carcass value?
carcass weight
cutability or sealable meat yielf
quality of the lean meat
How does carcass weight affect the carcass value?
- correlated to how much meat we can produce from a carcass
- weight used to pay the producers
- need a certain amount of weight before slaughter so the weight dictates when the producer can send the animal to slaughter
How does cutability or sealable meat yield affect the carcass value?
- related to lean meat production
- excess of fat can become a problem
How does quality of the lean meat affect the carcass value?
carcass characteristics influence appearance, shelf life and eating quality of final product
What are some criteria used in beef grading?
Maturity/age of carcass
Gender determination
Fat colour
Yield grade - measurements at ribeye
Quality grade - marbling score
How does maturity/age of the carcass affect meat quality?
collagen in connective tissue presents covalent crosslinks between collagen molecules which causes collagen stabilization -> however causes tougher meat
What is collagen in connective tissue?
collagen is a structural protein synthesized by fibroblasts and the main component of connective tissue
What is the relationship between tough meat, collagen and age?
older animals -> lower solubility of collagen -> tougher meat
Explain the maturity/age of the carcass and the collagen levels table
WBSF - instrumental tenderness, the higher the number, the tougher the meat, can be seen that as the animal ages the number gets higher
TCC - amount of collagen, goes up as the animal ages
CS% - collagen solubility, goes down as the animal ages
What is ossification?
when the bone mineralizes, it reforms new bone through osteoblasts
What can ossification be related to?
assess for cartilaginous caps on the thoracic vertebrae
it is correlated to collagen insolubility and consequently decreases in tenderness
How does gender determination affect carcass grading?
- sex alters the tissue deposition pattern
What are graders assessing for in gender determination of meat?
assess for pronounced masculinity
What is the difference between male castrated vs non-castrated meat?
non-castrated
- greater lean tissue deposition
- less fat deposition - decreased marbling
- greater predisposition to produce DFD meat
- darker colour: more oxidative metabolism
- less acceptable
How can you tell the difference between a male and female when alive vs when slaughtered?
crestiness on the neck
presence of an erector muscle only in males
How does fat colour influence beef grading?
if the fat is too yellow - it won’t qualify for A/prime grading
fat must be assessed as firm and consistent
How does yellow fat occur?
associated with the type of feeding
grass-fed animals have a greater deposition of beta-carotene
cattle fed diets rich in grains will change the colour of the fat and decrease the yellowness
How is yield grade assessed on the carcass?
evaluating the cross-section between the 12th and 13th rib
site of the longissimus muscle with a high and positive correlation with muscularity of the carcass
What is the relationship between the longissimus muscle and yield?
increase in ribeye area (longissimus dorsal area)
increase in amount of lean tissue in the carcass
What are the three things measured during yield grading?
- ribeye length
- ribeye width
- subcutaneous fat thickness
