Physiological role of indigenous milk enzymes: An overview of an evolving picture

Over 60 indigenous enzymes have been identified so far in the milk of various mammalian species. The vast majority of research in this area has focused on their use as indicators of processing (mainly pasteurization), contribution to dairy product quality and investigating the factors that affect their level in milk. The aim of this article is to provide an overview of data accumulated during the last 5 years, mostly for bovine and human milk, which shows that milk indigenous enzymes play a key role in regulating lactogenesis, e.g., inducing active involution, and that they are essential components of antioxidation and the innate immune system of milk.