ABSTRACT
Indigenous enzymes catalyze numerous desirable changes in most food groups but the importance of these changes depends on the particular product; a desirable change in one product may be deleterious in another and this may apply even between different products of the same group. Crude enzyme preparations have been unwittingly used in food processing since prehistoric times, e.g., calf veils in cheese manufacture, bruised papaya leaves to tenderize meat, and malt in brewing and distilling. Milk is rich in xanthine oxidase, an enzyme capable of oxidizing a range of aldehydes and purines. The flavor of meat and fish is an important property, but it is also extraordinarily complex as is evident from a number of reviews. Meat is an excellent source of high quality protein and of the B-complex vitamins and for these reasons contributes significantly to the dietary balance of meals.
