animal, plant & soil science lesson c6-2 meat product quality

Animal, Plant & Soil ScienceLesson C6-2Meat Product Quality

Interest Approach Display several different pictures or posters of

animal carcasses and meat products. Ask students to evaluate the images. Have them rank the images based on quality, yield, tenderness, and nutritional value. Discuss what makes each carcass or meat product different/unique. Provide the opportunity for students to judge a ring of rib eyes or pork chops.

Objectives Examine the physical and chemical

composition and nutritional value of meat products.

Identify the wholesale and retail cuts of beef, pork, and lamb.

Describe the beef grading system; analyze factors that affect quality and yield grades; and practice calculating yield and quality grades.

Objectives Describe the swine grading system, and

analyze factors that affect quality and yield grades.

Describe the lamb grading system, and analyze factors that affect quality and yield grades.

Demonstrate the ability to estimate quality and yield grades of live animals.

Terms conformation marbling nutrient density type

What are the physical and chemical compositions of meat products? What are the nutritional values of meat products?

The physical composition of meat is what can actually be measured.

The muscle or lean, fat, bone, and connective tissue are the main components of the physical features of meat products.

Chemical composition and nutritional values are directly related.


A. The chemical composition of a muscle determines its nutritive value as meat. Muscles are composed of water, protein, fat, and

minerals. Vitamins are also found

within meat. Fat-soluble vitamins like

A, D, E, and K are in the fat, and B vitamins are in the muscle.


B. The nutritive value of meat provides a balance of vitamins and minerals and is known as nutrient-dense. Nutrient density is a measurement

of the food value. This compares the number of

calories in food to the amount of essential nutrients available.


1. Iron is found in red meats and helps to build and maintain blood hemoglobin.

2. Zinc is found in red meats and helps with tissue development and growth.

3. Red meats provide B vitamins (e.g., niacin, riboflavin, B6, B12, and thiamine) and are an excellent source of protein.

What are the wholesale and retail cuts of beef, pork, and lamb?

The major wholesale cuts of beef, pork, and lamb are beneficial in understanding tenderness and quality.

The location of these cuts influences the price of the finished product.

A. The wholesale and retail cuts of the beef carcass are as follows:


1. Round—This contains the following retail cuts: round steak, top round roast, top round steak, boneless rump roast, bottom round roast, tip roast (cap off), eye round roast, and tip steak.


2. Sirloin—This contains the following retail cuts: sirloin steak, sirloin steak round bone, top sirloin steak, tenderloin roast/steak, and beef tri-tip (boneless cut from the bottom of the sirloin can also be called a “triangle”).


3. Short loin—This contains the following retail cuts: boneless top loin steak, T-bone steak, Porterhouse steak, and tenderloin roast/steak.

4. Rib—This contains the following retail cuts: rib roast (large end), rib roast (small end), rib steak (small end), rib eye steak, rib eye roast, and back ribs.


5. Chuck—This contains the following retail cuts: chuck eye roast, boneless top blade steak, arm pot roast, boneless shoulder pot roast, cross-rib pot roast, mock tender, blade roast, under blade pot roast, 7-bone pot roast, short ribs, and flanken-style ribs.

6. Brisket—This contains the following retail cuts: brisket (whole), corned brisket point half, and brisket flat half.

7. Shank—This contains shank cross cut.


8. Plate—This contains skirt steak. 9. Flank—This contains the following retail

cuts: flank steak and flank steak rolls.

10. Other retail cuts include ground beef, cubed steak, stew meat, and cubes for kabobs.


B. The wholesale and retail cuts of the pork carcass are as follows:

1. Leg—This contains the following retail cuts: bone-in fresh ham, smoked ham, leg cutlets, and fresh boneless ham roast.


2. Loin—This contains the following retail cuts: sirloin chop, rib chop, loin chop, boneless rib end chop, chef’s prime filet, boneless center loin chop, America’s cut butterfly chop, center rib roast, bone-in sirloin roast, boneless center loin roast, boneless rib roast, chef’s prime (boneless sirloin roast), tenderloin, Canadian-style bacon, country-style ribs, and back ribs.


3. Shoulder butt—This contains the following retail cuts: bone-in blade roast, boneless blade roast, ground pork, sausage, and blade steak.

4. Picnic shoulder—This contains the following retail cuts: smoked picnic, arm picnic roast, and smoked hocks.

5. Side—This contains the following retail cuts: spareribs, slab bacon, and sliced bacon.


6. Other retail cuts include cubed steak, pork pieces, cubes for kabobs, ground pork, and sausage links.


C. The wholesale and retail cuts of the lamb carcass are as follows:

1. Leg—This contains the following retail cuts: whole leg, short cut leg (sirloin off), shank (portion roast), center leg roast, center slice, American-style roast, Frenched-style roast, boneless leg roast, hind shank, sirloin chop, and boneless sirloin.


2. Loin—This contains the following retail cuts: loin roast, loin chop, and double loin chop.

What are the wholesale and retail cuts of beef, pork, and lamb? 3. Rib—This contains the following retail cuts: rib

roast, rib chop, Frenched rib chop, and crown roast. 4. Shoulder—This contains the following retail cuts:

square-cut shoulder (whole), pre-sliced shoulder, boneless shoulder roast, neck slice, blade chop, and arm chop.

5. Foreshank and breast—This contains the following retail cuts: shank, spareribs, boneless rolled breast, and riblets.

6. Other retail cuts include lamb for stew, cubes for kabobs, and ground lamb.

What is the beef grading system? What are the factors that affect quality and yield grades of beef carcasses? How do you calculate yield and quality grades?

Beef carcasses are graded for yield and quality grades, based on the degree of maturity and the degree of marbling.


Beef yield grade is an estimate of the percent yield for the four primal cuts of beef: chuck, rib, loin, and round. Yield grade is also referred to as cutability.

A. Quality grading is an important factor in consumer satisfaction. The color and texture affect meat palatability,

flavor, and juiciness.


1. As the animal ages (matures), the cartilage becomes bone, the lean/meat darkens, and the texture becomes coarser. Maturity refers to the physiological age of the

carcass. Maturity indicators are bone characteristics,

ossification of cartilage, and color/texture of the rib eye muscle.


2. Marbling (the intramuscular fat in the lean) is the factor on which quality grading is based. This can be evaluated between the 12th and 13th

ribs. The amount and

distribution of the marbling in the rib eye is evaluated at the cut surface.


B. USDA yield grades for beef carcasses are rated numerically from 1 to 5.

Yield Grade 1 will display the highest yielding carcass, and Yield Grade 5 will be the lowest.

To find yield grades, a carcass is evaluated on the following factors:

1. Amount of external fat—The external fat is measured at the 12th rib (measuring the thickness of fat ¾ the length of the rib eye from the chine bone).


2. Hot carcass weight—The hot carcass weight is the weight taken at the harvesting facility before the carcass is chilled.


3. Amount of kidney/pelvic/heart (KPH) fat—The amount of KPH is evaluated and expressed as a percentage of the carcass weight.

4. Area of the rib eye muscle—The area of the rib eye muscle is determined by using a dot-grid. This measurement is taken at the 12th rib.

What is the swine grading system? What are the factors that affect quality and yield grades of swine carcasses?

The swine grading system varies slightly, depending on the class of carcass.

Various factors can affect the quality and yield grades.


A. The swine grading system uses muscling scores and back fat thickness to determine USDA Grades. Barrow, gilt, sow, boar, and stag are the harvest

swine carcass classes. Barrows and gilts are classed together with grade standards.

Sows have different grade standards. Boars and stags are not commonly used in major

swine carcass production because the boar flavor is unacceptable for grading; therefore, no official grade standards exist for boars or stags.


B. Grades for barrows and gilts are based on the quality characteristics of the lean and expected combined yields of the four lean cuts: ham, loin, Boston shoulder, and picnic shoulder.

1. The degree of muscling of a swine carcass is categorized as: a. Muscle Score #1—thin/inferior muscling b. Muscle Score #2—average c. Muscle Score #3—thick/superior muscling


2. The whole carcass and the loin eye area are used to determine the muscling score. The area between the 10th and 11th rib is used to

measure carcass muscle. The levels of quality are “acceptable” and

“unacceptable.” The quality is determined by viewing the cut

surface of the loin at the 10th rib.


a. Quality characteristics (e.g., gray-pink in color, fine muscle fibers, and good marbling) are indicators of an acceptable lean/meat.


b. Yields of the lean cuts (ham, loin, Boston shoulder, and picnic shoulder) will differ due to the amount of fatness, muscling, and skeletal size. USDA Grade for swine carcasses is determined by

using the following formula: (4.0 × last rib back fat thickness

(in inches) – 1.0 × muscle score). The muscle score is determined

by using the following: thin = 1.0, average = 2.0, and thick = 3.0.

What is the lamb grading system? What are the factors that affect quality and yield grades of lamb carcasses?

Sheep are classified by sex and maturity. Sheep are graded for quality and yield grades.

Young lamb carcasses (2 to 14 months of age) have a characteristic break joint on one of their shanks after the front legs are removed.

On mutton carcasses, the break joints have ossified. Yearling mutton carcasses range in age from 12 to 15

months. The yearling mutton differs from a traditional mutton

carcass by the color of the lean (pinkish red to a dark red) and shape of the rib bones.


A. The quality grade in a lamb carcass is determined by the maturity, conformation, and flank streaking.

1. Maturity is determined by bone color/shape and lean color.


2. Conformation of a carcass is the overall thickness of the muscling. Lamb carcasses are not ribbed; therefore, the rib-

eye areas are not exposed and cannot be used for an overall evaluation of marbling.


3. Flank streaking is used to predict marbling in a lamb carcass. The streaks of fat in the

flank muscle are used to determine marbling.


The grades for lambs are: a. Prime (highest) b. Choice (most lambs fall

into this category) c. Good d. Utility


B. Yield grades are an estimate of the retail cuts from the leg, loin, rack, and shoulder. The yield grade of a lamb carcass can be found by

using the following equation: (Back fat × 10) + 0.4.

For example, if a lamb carcass had 0.20 inches of back fat, the yield grade would equal (0.20 × 10 = 2.0) + 0.4 = yield grade of 2.4.


The yield grades of lamb carcasses range from USDA 1 to 5. USDA 1 is the most desirable, showing minimum fat and heavy muscle. USDA 3 grade is average. USDA 5 grade is the least

desirable, showing light muscle and heavy fat.

How are quality and yield grades of live animals estimated?

The ability to estimate quality and yield grades of live animals helps livestock producers and breeders evaluate livestock and determine the correct time to market animals.

Buyers and packers also evaluate live animals for correctness of condition and estimate yields.

Ultrasound technology helps with this process; however, visual evaluation is faster and less expensive.


In evaluating live animals, type is used to describe an ideal or standard that combines characteristics of an animal’s use for a specific purpose.

Conformation describes the animal’s external form and shape.

Visual evaluation of the different stages can be used to predict carcass composition.


A. Understanding the different productive stages of livestock is important to class and common animals. 1. The breeding or reproduction

stage is based on performance records.

2. The feeder or growth stage is based on efficiency and weight gain.

3. The harvest or carcass/product stage refers to the final product.


B. Understanding the external body parts of each animal helps the evaluator communicate effectively as the appraisal is being conducted.

C. Understanding the location of the wholesale cuts in live animals is the next step in learning how to appraise livestock animals. This allows the evaluator to direct the attention

toward lean cuts and to visualize the hanging carcass.

How are quality and yield grades of live animals estimated? D. Major factors to consider when evaluating

livestock and estimating quality and yield grades: 1. Age/maturity of the animal—Consider the animal’s age

by evaluating bone structure, teeth, and evidence of the chine bone.

2. Marbling potential—Reference points on an animal (loin, ham, leg of a lamb) should be noted.

3. Hide color—This is a factor to consider when evaluating livestock. Beef animals with black hides typically perform higher on quality

tests. 4. External fat—The loin, tail-head, and dock area of sheep

should be examined for external fat. This follows a trend of having more marbling.

Review What are the physical and chemical

compositions of meat products? What are the nutritional values of meat products?



Review What is the swine grading system? What are

the factors that affect quality and yield grades of swine carcasses?



animal, plant & soil science lesson c6-2 meat product quality

Documents

physical composition

nutritive value of meat

retail cuts of beef

meat product differentunique

quality grades

major wholesale cuts

following retail cuts

beef carcass