Fresh pineapple contains the enzyme bromelain that hydrolyzes peptide bonds in proteins.
<IMAGE>
b. Fresh pineapple is used in a marinade to tenderize tough meat. Why?

Verified step by step guidance

1. Fresh pineapple contains the enzyme bromelain, which is a proteolytic enzyme. Proteolytic enzymes are specialized in breaking down proteins by hydrolyzing peptide bonds.
2. Meat is primarily composed of muscle proteins, which contribute to its toughness. These proteins are held together by peptide bonds.
3. When fresh pineapple is used in a marinade, the bromelain enzyme interacts with the proteins in the meat, catalyzing the hydrolysis of peptide bonds. This breaks the proteins into smaller peptides and amino acids.
4. The breakdown of proteins reduces the structural integrity of the muscle fibers, making the meat softer and more tender.
5. This enzymatic action is why fresh pineapple is effective in tenderizing tough meat when used in a marinade.

Key Concepts

Bromelain

Bromelain is a proteolytic enzyme found in fresh pineapple that breaks down protein molecules by hydrolyzing peptide bonds. This enzymatic activity is responsible for the tenderizing effect of pineapple on meat, as it helps to denature and degrade the proteins, making the meat softer and easier to chew.

Protein Hydrolysis

Protein hydrolysis is a biochemical process where peptide bonds in proteins are broken down into smaller peptides or amino acids, often facilitated by enzymes like bromelain. This process is crucial in cooking and food preparation, as it alters the texture and digestibility of proteins, enhancing the overall quality of the dish.

Marinade

A marinade is a mixture typically composed of acidic ingredients, oils, and seasonings used to soak food, particularly meat, before cooking. The acid in marinades, such as those from fruits like pineapple, helps to tenderize the meat by promoting protein hydrolysis, while also infusing flavor into the dish.