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• diagram the structure and of muscle and meat and relate to tender and less tender and color of meat.
• identify generally tender or less tender cuts of pork, beef, lamb meat.
• diagram the pigments that are important to the color of meat.
• summarize how production and processing may impact meat quality.
• select the optimum method of preparation to produce a tender, flavorful meat product.
• discuss food safety handling procedures and temperatures for meats.

A review of some of the standard basic information on meat should give the foundation needed to understand a little bit more about meat. A discussion of meat involves four different components: the muscle, the fat, the connective tissue, and the bones. All these components integrate together to give the meat the quality that you and I taste when we eat it, however, individually they do react differently and do give different characteristics to the ultimate meat quality.

Proximate Composition of Beef, Pork, and Lamb

Composition	Beef	Pork	Lamb
Water
Protein
Fat
Carbohydrate

This discussion will focus on the muscle itself and how it relates to quality depending upon its structural composition. As you recall, the muscle itself contains anywhere from 70 to 75 percent water; the fat content will range, depending on the grade of animal, from approximately 2 to 8 percent fat. Protein content of the muscle varies from 17 to 22 percent. There are a number of minerals which cannot be disregarded in their importance, however, they are of less amounts in total muscle composition.

	Of course, the composition of the meat will depend not only on the animal and its growing environment but will depend on whether it's a rib steak or flak steak. Individually, meat varies in characteristics not only because of composition, but ultimately, because of the muscle fiber. A flank steak with a muscle fiber being excised, that is actually removed, indicates its size. This flake steak happens to be the piece of meat which has some of the largest muscle fibers in the animal.
	A muscle fiber has been variously described. One description calls it an envelope or package surrounded with connective tissue and enclosing the sarcoplasm, the mitochondria, and a number of other components. The diagram shows the typical muscle fiber. As shown diagrammatically, it consists of a large number of nuclei. The micrograph of the fiber, as viewed through the light microscope gives some more detail of the muscle structure. The muscle fibers cut on end as viewed using a scanning electron microscope gives even more detail. Although some knowledge of the quality of meat may be obtained form the composition , the structure of the fiber itself is also critical. Investigators are believing increasingly that the reticulum or ground substance, which up until recently has been underemphasized, is very important to the characteristics and behavior of the muscle.
	The muscle fiber itself is not the ultimate unit of the muscle. The muscle fiber does have an organizational network within the sarcolemma. In the sarcoplasm are the myofibril proteins. The myofibril proteins consisting of actin and myosin, are organized into myofibrils and myofilaments. The myofibril proteins and sarcoplasm and other cellular fiber constituents are enclosed within connective tissue. Thus, connective tissue is not only found as collagen and elastin in the ligaments and tendons; but, it is an important constituent within the muscle. Muscle fibers may be bundled together within the muscle with connective tissue. The connective tissue is the covering in the muscle. Surrounding the muscle is a connective tissue covering called the epimysium. If the muscle contains fiber bundles they are enclosed with a connective tissue covering called the perimysium. The endomysium are sarcolemma is the covering of the muscle fiber itself.

The part of the carcass that the meat comes from will impact the tenderness and less tender texture of the meat.

	Basically, these can also be determined from the individual cut of meat. For example, the more muscles are used, generally the tougher the piece of meat. In the past it was relatively easy to differentiate the different cuts by the bone. If a round bone or long narrow bone was in the cut of meat it was less tender, if a t-bone or rib bone was present it is a tender cut of meat.
	If one could view a muscle fiber within a live animal they could predict, to some degree, the toughness and tenderness of the muscle. Here, muscle fibers, as viewed through a light microscope, they are a zigzag arrangement. Generally speaking, this zigzag type of arrangement would indicate a tough piece of mean.

	The breed of animal. It is well established that different breeds of the species will impact the quality. Additionally, the genus would make a difference in the quality.
	Environment for production
	Post-mortem Treatments will impact the tenderness and toughness of the meat. If it is allowed to undergo cold-shortening, improper rigor development, the meat may be tougher. Electrical stimulation, hanging the meat properly, prerigor pressurization will all tenderize the meat.

GLOSSARY

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• ATP is adenosine triphosphate, a compound containing high-energy phosphate bonds in which the body cell traps energy from the metabolism of carbohydrate, fat, or protein, the enrgy in ATP is then used to do mechanical or chemical work in the body.
• BASTE is to spoon or dribble liquid over the food as it cooks.
• BRAISE is to cook meat or poultry slowly in a covered utensil in a small amount of liquid or in steam.
• BROIL is to cook via direct exposure to radiant heat.
• CAROTENOID PIGMENTS are the fat-soluble, yellow-orange pigments that are produced by plants; may be stored in the fatty tissues of animals.
• CYTOPLASM is pertaining to the protoplasm of a cell, exclusive of the muscles.
• DREDGE is to sprinkle or coat with flour or other fine "breading".
• FRY is to cook in fat.
• HYDROLYZE is to break a molecular linkage utilizing a molecule of water.
• MARBLING is the distribution of fat throughout the muscles of meat animals.
• METMYOGLOBIN is the oxidized (ferrous to ferric) myoglobin and oxymyoglobin to a brownish color.
• MITOCHONDRIA is the sausage-shaped bodies in the cell cytoplasm that contain the enzymes necessary for energy metabolism.
• MUCOPROTEIN is a complex or conjugated protein containing a carbohydrate substance combined with a protein.
• MYOGLOBIN is the muscle pigment which accepts oxygen into the muscle. It contains protein (globin) and the iron-containing pigment heme. Generally, a purple-red color.
• OXYMYOGLOBIN is the oxygenated myoglobin that has had oxygen added to myoglobin. Generally a bright red color.
• PRECURSOR is a substance that "comes before".
• PROTEINASE is an enzyme that hydrolyzes proteins to smaller peptides and amino acids.
• RETICULUM is a netlike sheath.
• RIGOR MORTIS is due to the metabolic changes that continue to occur upon death.