eChapter Name: Milk Enzyme
9789358875225
eBook Name: CHEMISTRY OF MILK AND MILK PRODUCTS
by Pinaki Ranjan Ray
Types of Enazymes in milk
1. Endogenous and 2. Exogenous.
Three sources of enzyme in milk:
1. The blood via defective mammary cells.
2. Secretory cell cytoplasm. Some of which are occasionally entrapped with fat globules by the encircling MFGM.
3. The outer layer of MFGM is probably the principal source of endogenous enzymes in milk. The outer layer of MFGM is derived from the apical membrane of the secretory cell which in turn originates from the Golgi membrane and acts as the principal source of enzyme in milk.
General Characteristics of Milk Enzymes
1. Deteriorative character e.g. lipase (commercially most important enzyme in milk), proteinase, acid phosphatase, xanthine oxidase.
2. Preservative enzymes. e.g. superoxide dismutase, sulfhydryl oxidase.
3. As an indicator of the thermal treatment history of milk. Related enzymes are alkaline phosphatase, ϒ glutamyl transpeptidase, and lactoperoxidase.
4. Mastitis infection indicator. Related enzymes are catalase, n-Acetyl-β D-glucosaminidase, and acid phosphatase.
5. Antimicrobial activity.
6. Commercial source of ribonuclease and lactoperoxidase
Common Milk Enzymes and their Role in Dairy Industry