Transcript Welcome to the Wonderful World of Meat!

Welcome to the
Wonderful World of Meat!
Compiled by Justin Wiebers, Extension Agent, 4-H, University of Tennessee Agricultural Extension Service
Quality Grades
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Quality grades reflect the flavor and
tenderness of meat and are primarily
determined from carcass maturity and the
amount of fat within the meat (i.e. marbling
or intramuscular fat).
USDA Quality Grades for Beef
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USDA Prime
USDA Choice
USDA Select
USDA Standard
USDA Commercial
USDA Utility
USDA Cutter
USDA Canner
Other Preferred Quality Grades
LAMB
•USDA Prime- highest in tenderness, juiciness, and flavor
•USDA Choice- very high in tenderness, juiciness, and flavor
PORK
•USDA Acceptable Quality- very lean, firm, with grayish pink color
USDA Beef Quality Grades
Official USDA Marbling Photos
Moderately
Abundant
Slightly
Abundant
Moderate
Modest
Small
Slight
Official USDA Marbling Photos
USDA Prime: Prime grade
beef is the ultimate in
tenderness, juiciness, and
flavor. It has abundant
marbling -- flecks of fat within
the lean -- which enhances
both flavor and juiciness.
Prime roasts and steaks are
unexcelled for dry-heat
cooking (roasting and broiling)
Official USDA Marbling Photos
Official USDA Marbling Photos
USDA Choice: Choice grade beef
has less marbling than Prime, but is
of very high quality. Choice roasts
and steaks from the loin and rib will
be very tender, juicy, and flavorful
and are, like Prime, suited to dryheat cooking. Many of the less
tender cuts, such as those from the
rump, round, and blade chuck, can
also be cooked with dry heat.
Official USDA Marbling Photos
Official USDA Marbling Photos
USDA Select: Select grade beef is
very uniform in quality and
somewhat leaner than the higher
grades. It is fairly tender, but,
because it has less marbling, it may
lack some of the juiciness and
flavor of the higher grades. Only
the tender cuts should be cooked
with dry heat. Other cuts should be
marinated before cooking or
cooked with moisture to obtain
maximum tenderness and flavor.
Official USDA Marbling Photos
Standard and Commercial:
This grade of beef frequently is sold
as ungraded or as "brand name"
meat.
The three lower grades -- USDA
Utility, Cutter, and Canner -- are
seldom, if ever, sold at retail but are
used instead to make ground beef
and manufactured meat items such
as frankfurters
Maturity
The age of a beef animal has a direct effect on tenderness of the meat
it produces. As cattle mature, their meat becomes progressively
tougher. To account for the effects of the maturing process on beef
tenderness, evaluations of carcass maturity are used in determining
USDA Quality Grades. There are five maturity groupings, Designated
as A through E below.
Approximate ages corresponding to each maturity classification are:
A - 9 to 30 Months
B - 30 to 42 Months
C - 42 to 72 Months
D - 72 to 96 Months
E - More Than 96 Months
Official USDA Quality Grades
Yield Grades
USDA yield grades identify the "quantity" or "cutability" differences
among carcasses. Yield grades are 1, 2, 3, 4 and 5, and are a numerical
representation of the expected percentage of closely trimmed,
boneless retail cuts from the round, loin, rib and chuck. This
percentage of retail cuts is the carcass cutability
Yield Grade
1
2
3
4
5
% Boneless, Closely Trimmed Retail Cut
From the Round, Loin, Rib and Chuck
52.6 - 54.6
50.3 - 52.3
48.0 - 50.0
45.7 - 47.7
43.3 - 45.4
Yield Grades
Carcass factors used to calculate yield grade
•Adjusted fat thickness
•Percentage of Kidney, Pelvic and Heart
Fat (KPH)
•Rib Eye Area
•Hot Carcass Weight
Adjusted Fat Thickness
External fat is measured at the 12th rib perpendicular to the outside fat
at a point 3/4 the length of the rib eye (longissimus) muscle. This
measurement may be adjusted by the grader to reflect unusual fat
distribution in the carcass. Special attention is given to fat deposition in
the cod or udder, rump, inside round, flank, lower rib, plate and brisket
areas. External fat is the most important yield grade factor. As external
fat increases, the percentage of retail cuts decreases.
Percentage of
Kidney, Pelvic and Heart Fat
This is a subjective estimate of the amount of fat surrounding the kidney
knob, and fat in the pelvic and thoracic (heart) areas as a percentage of
the carcass weight. As the percentage of KPH fat increases, the
percentage of retail cuts decreases. Percentage KPH fat normally
ranges from 1.0 to 4.0 percent.
Rib Eye Area
The longissimus muscle is measured at the 12th rib by using a grid
expressed in square inches, or a compensating polar planimeter, which
measures a rib eye tracing. Rib eye area is an indicator of carcass
muscling; as rib eye area increases, retail cut yield increases.
Hot Carcass Weight
Generally, as carcass weight increases, the percentage of retail cuts
decreases slightly due to increased fat deposits. If only chilled carcass
weight is available, it can be adjusted to hot carcass weight by
multiplying by 1.02 to correct for the evaporative weight loss of the
carcass in the cooler.
Calculating Yield Grade
Yield grades are calculated by using the
following formula:
YG = 2.50
+ (2.50 × Adjusted Fat Thickness, inches)
+ (0.20 × Kidney, Pelvic and Heart Fat %)
+ (0.0038 × Hot Carcass Weight, lb)
- (0.32 × Rib eye area, sq. in.)
Calculating Yield Grade
For example, a carcass has 0.40 inch of fat, 2.5
percent KPH, 12.8 sq. inches of rib eye and a hot
carcass weight of 750 lbs. Substitute these
variables into the yield grade equation to calculate
a final yield grade of 2.75:
YG = 2.50 + (2.50 × 0.4 in.)
+ (0.20 × 2.5 percent)
+ (0.0038 × 750 lbs.)
- (0.32 × 12.8 sq. in.)
YG = 2.75
Compiled by Justin Wiebers, Extension Agent, 4-H, University of Tennessee Agricultural Extension Service