ABSTRACT
Many changes that occur in fresh foods during storage are catalyzed by enzymes. Enzymatic activity affects many of the major food commodity groups: (1) fruits and vegetables, (2) cereals, legumes, and grains, (3) meat, poultry, and sea food, (4) beverages, including tea, chocolate, soft drinks, and wine, (5) milk and dairy products, (6) candy and confectionery. Preprocessed foods contain enzymes whose activity affects product quality in profound ways. Enzymes are also used in many food manufacturing processes. The production of cheese and high fructose syrup are examples of enzymatic food processes. Food enzymes can be divided into two classes: (1) endogenous enzymes are those that are naturally present in foods and which affect quality; and (2) exogenous enzymes, which are mostly isolated from bacteria, and are added to foods as processing aids. Papain isolated from papaya latex, and other plant proteases, are a notable exceptions to this rule.
