Final answer:
Protein-rich foods can be treated by curing with salts and sugars or by marinating in acidic solutions with seasonings to add flavor and alter texture without the use of heat.
Step-by-step explanation:
Two examples of how protein rich food can be treated other than cooking with heat are curing and marinating. Curing involves adding a combination of salt, sugar, and sometimes nitrates or nitrites to meat or fish to preserve and flavor the food. This method can also begin the protein breakdown process, making it more palatable and digestible. Marinating, on the other hand, uses a mixture of acids (like vinegar or citrus juice) and herbs or spices to both flavor and tenderize proteins. The acid in the marinade can partially denature proteins, making them softer and altering the texture before any heat is applied.