Composition, Structure, and Basic
Quality Factors

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Composition of Meat

Muscle tissue consists of these major components:

Water (about 75% of muscle tissue)

With such a high percentage of water in meat, you can see why shrinkage can be a big problem in cooking meat.

Protein (20% of muscle tissue)

Protein is an important nutrient and the most abundant solid material in meat.

Protein coagulates when it is heated. This means it becomes firmer and loses moisture. Coagulation is related
to doneness: when protein has coagulated to the desired degree, the meat is said to be "done."

Too high heat toughens protein.

Fat (up to 5% of muscle tissue)

Of course, there can be more fat surrounding the muscles. A beef carcass can be as much as 30 % , fat.

A certain amount of fat is desirable for three reasons:

1. Juiciness

Marbling is fat that is deposited within the muscle tissue. The juiciness we enjoy in well-marbled beef is due more to fat than to moisture.

Surface fat protects the meat-especially roasts-from drying out during cooking as well as in storage. Adding surface fats where they are lacking is called barding.


Marbling separates muscle fibers, making them easier to chew.

3. Flavor

Fat is perhaps the main source of flavor in meat. A well-marbled Prime (top grade) steak tastes "beefier" than the same cut of a lower grade.


Meat contains a very small amount of carbohydrate. When you brown meat, you are, in part, caramelizing the carbohydrate.


Muscle fibers

Lean meat is composed of long, thin muscle fibers bound together in bundles. These determine the texture or grain of
a piece of meat. Fine-grained meat is composed of small fibers bound in small bundles. Coarse-textured meat has larger fibers.

Connective tissue

Muscle fibers are bound together in a network of proteins called connective tissues. Also, each muscle fiber is covered
in a sheath of connective tissue.

It is very important for the cook to understand connective tissue for one basic reason: connective tissue is tough.

To cook meats successfully, you should know:

Which meats are high in connective tissue and which are low.
What are the best ways to make tough meats tender.

1. Meats are highest in connective tissue if:
a. They come from muscles that are more exercised. Muscles in the legs, for example, have more connective tissue than muscles in the back.
b. They come from older animals. Veal is tenderer than meat from a young steer, which in turn is tenderer than meat from an old bull or COW. (Young animals have connective tissue, too, but it becomes harder to break down as the animal ages.)

2. Meats high in connective tissue can be made more tender by using proper cooking techniques.

There are two kinds of connective tissue: collagen, which is white in color, and elastin, which is yellow.

Moist heat turns collagen into gelatin and water. Moist heat at low temperatures for a longertime is most effective in
creating a tender, juicy finished product.

Other factors also help tenderize collagen:
Acid helps dissolve collagen. Marinating meat in an acid mixture, or adding an acid such as tomato or wine to the
cooking liquid, helps tenderize.
Enzymes are naturally present in meat. They break down some connective tissue and other proteins as meat ages.
Tenderizers are enzymes such as papain (extracted from papaya), which are added to meats by the cook. Too long
an exposure at room temperature can make the meat undesirably mushy.


Older animals have a higher proportion of elastin than younger animals.

Elastin is not broken down in cooking.
Tenderizing can only be accomplished by removing the elastin (cutting away any tendons) and by mechanically
breaking up the fibers, as in:

Pounding and cubing (cubed steaks).
Grinding (hamburger).
Slicing the cooked meat very thin against the grain (as in London broil).

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