ABSTRACT

Milk and milk products contain a large number of enzymes, either natural or produced by certain microorganisms. The most common enzymes present in dairy products are proteinases, lipase, lactase, catalase, xanthine oxidase and lactoperoxidase. This chapter discusses the role of enzymes in cheese, fermented milk products, removal of off-flavors in milk products and as bio-detergents for cleaning dairy equipments. Lactase, proteinases and peptidases are important for fermentation of milk. Cheese ripening is a complex process mediated by biochemical and biophysical changes during which a bland curd is developed into a mature cheese with characteristic flavor, texture and aroma. The other enzymes having limited applications in dairy processing include glucose oxidase, catalase, Sulfhydryl oxidase, lactoperoxidase and lysozymes. Lipases can generally be categorized as enzymes that catalyze the hydrolysis of lipids, which are the major lipid component of milk. The only cross-linking enzyme that is available for catalysing covalent bond formation between protein molecules on a commercial scale is transglutaminase.