Collagen is the primary muscle protein responsible for meat tenderness. It is a connective tissue protein that holds muscle fibers together. As an animal ages, the amount of collagen in its muscles increases, making the meat tougher.

Proteolysis is the process of converting muscle to meat. It is a series of enzymatic reactions that break down muscle proteins into smaller, more tender compounds.

Overcooking is the term for the condition in which meat becomes tough and dry due to excessive cooking. This occurs when the proteins in the meat are denatured and become tough.

PSE (pale, soft, and exudative) is the term for the condition in which meat becomes pale, soft, and exudative due to rapid post-mortem pH decline. This occurs when the muscle glycogen is rapidly converted to lactic acid, causing a rapid decrease in pH.

DFD (dark, firm, and dry) is the term for the condition in which meat becomes dark, firm, and dry due to delayed post-mortem pH decline. This occurs when the muscle glycogen is not rapidly converted to lactic acid, resulting in a slow decrease in pH.

Freezing is the primary method used to preserve meat. It slows down the growth of microorganisms and enzymatic reactions, thereby extending the shelf life of the meat.

Salting is the process of curing meat. It involves adding salt to the meat, which helps to preserve it by inhibiting the growth of microorganisms and enzymatic reactions.

Smoking is the term for the process of smoking meat. It involves exposing the meat to smoke from burning wood or other materials, which helps to preserve it and imparts a characteristic flavor.

Drying is the term for the process of drying meat. It involves removing moisture from the meat, which helps to preserve it and concentrate its flavor.

Fermentation is the term for the process of fermenting meat. It involves using microorganisms to convert the sugars in the meat into acids, which helps to preserve it and impart a characteristic flavor.

Bacteria are the primary cause of foodborne illness from meat. They can contaminate meat during slaughter, processing, or storage. Some common bacteria that can cause foodborne illness include Salmonella, E. coli, and Listeria monocytogenes.

Cooking meat to a safe internal temperature is the best way to prevent foodborne illness. This kills harmful bacteria that may be present in the meat.

The recommended internal temperature for cooking poultry is 165°F (74°C). This temperature is high enough to kill harmful bacteria that may be present in the poultry.

The recommended internal temperature for cooking ground beef is 165°F (74°C). This temperature is high enough to kill harmful bacteria that may be present in the ground beef.

The recommended internal temperature for cooking pork is 165°F (74°C). This temperature is high enough to kill harmful bacteria that may be present in the pork.