A lot can be said about meat in general. It may seem like Chicken and Beef have nothing in common, but they actually share a lot… because their Meat!

I am can’t say I am an expert in this area, but Harold McGee is! I have gleaned this information from his excellent book On Food and Cooking

Summary:

• Muscles are made up of Muscles fiber, connective tissue and fat
• Muscle fibers are tough to break. Carve across the muscle fibers, so you can chew with them
• Older, more exercised muscles have more flavor
• More exercised muscles are tougher
• Red muscle fibers give the meat its “meaty” flavor
• Fat is what give an animal its specific flavor, and is influenced by what it eats
• Older fat has more flavor
• Younger connective tissue is more easily dissolved

Meat can mean any body tissue of an animal that can be eaten as a food. This means anything from lungs to legs can be considered to be meat. This makes one reconsider what goes into hot dogs. While organ and innards can be considered meat, this article is going to focus on good old fashion muscle tissue.

Muscle

Muscles are designed to do only one thing, contract. Muscles are made up of three different tissues; muscles fibers, connective tissue and fat tissue. All of these determine the taste and texture of the meat. If you understand the role they play, you’ll have meat figured out.

Muscle Fibers

Muscle fibers are the part of muscle that do the actual work. They are long cells, sometimes running the length of the muscle. The cell contains two intertwined protein filaments that do the actual contracting. The number of muscle fibers in a muscle always stays the same. If a muscle get stronger, the number of protein filaments inside the fiber increase, not the number of fibers. The more of those protein filaments that are in cell, the harder it is to cut.

The muscle fibers are bound into bundles and it is these bundles that you can see when you cut into a piece of cooked meat. When you cut parrelall to the bundles of fiber you can see them from the side, all stacked up like the wall of a log cabin. If you cut across the bundle of fibers you would see the ends of each bundle. It is easier to pull the bundles apart than it is to cut them. Because of this, meat is usually cut across the fiber or grain. When you chew this means you have to cut less of the fiber with your teeth, making the meat easier to chew. Meat is carved across the grain, which allows you to chew with the grain.

Connective Tissue

The connective tissue in the muscle, connects it all together ( of course ) and harnesses the power of the muscle. The connective tissue also surrounds each of the muscle fibers and also groups them together into bundles. These bundles are also formed held together by the connective tissue to form the muscle.

The stronger and more powerful a muscle get, the thicker and tougher the connective tissue needs to be to harness the action of the muscle. The majority of the connective tissue in the muscle is made up of the protein collagen. Collagen is tough but when it is heated in water to partly dissolves into a gelatin. The collagen in younger animals dissolves more easily, and helps make young meat seem more tender.

Fat Tissue

The fat in meat is actually just another form of connective tissue that is also capable of storing energy.

Tenderness / Toughness

No one wants a tough piece of meat, and a lot goes into determining whether a cut of meat is tender or not. One of the biggest factors in tenderness is where the muscle comes. The more a muscle gets used the stronger it will be and the larger and tougher each muscle fibers will be. Usually the muscles used to support an animal, the arms, legs and shoulders, will be the toughest. Of course if an animal is younger then the muscles have had less of a chance to be exercised and are more tender. This is one of the reason why veal is more tender than beef. The collagen in the younger animals connective tissue also dissolves easier make the meat seem more juicy and tender.

The fat in a cut of meat also contributes to how tender it seems. When heated the fat melts and helps lubricate the muscle fiber and keep them separate. If a piece of meat is cook long enough for its collagen to dissolve, it can also play a similar role.

Flavor!

The type/color of muscle fiber plays a large role in determining the flavor of a cut of meat. Muscle type is determined by what it is designed to do, and the energy it uses.

White muscle fibers are designed for sudden and explosive effort, but they can only support this effort for a short amount of time. This is because they depend on stores of carbohydrates that are already in the fibers. When the fibers run out of energy and available oxygen they can no longer work. Red muscle fibers are designed for long, slower efforts and use fat as a source of fuel. In order to metabolize the fat, oxygen is needed, and the muscle fiber receives both from the blood. The muscle fibers have proteins necessary to convert the fat and oxygen to energy, and this is what give the fibers their red color. The more oxygen a muscle needs and the more it is exercised, it will contain more of these proteins and be darker in color.

How much meaty flavor a cut of meat has is determined by the type of muscle fiber it is made up of. A cut of meat with a high proportion of red muscle fibers that have been well exercised, will be more flavorful than a cut made up of white muscle fibers. The red fibers have more flavorful materials in them, including droplets of fat.

The flavor provided by the muscle fibers is generally the same no mater what the animal is. This is because they do the same thing no matter what animal the is, contract. It is the fat cells that provide the specific flavors for a cut of meat from a specific animal. The fat tissue in a muscle serves as storage and they can end up containing any fat soluble material. What gets stored in the fat depends on what type of animal it is, what it eats, and how it digests it. This is why you grain feed beef tastes different that grass feed beef. The flavor of the fat gets stronger as an animal gets older because more of the flavor compounds get stored in the fat.