Bioactive peptides in fermented milk products and their functionality

Abstract

Milk and milk products are the rich source of several health driven bioactive peptides. The presence of these bioactive peptides in fermented dairy products viz. cheese, yoghurt and sour milk helps in preventing oxidative stress mediated diseases. Several types of bioactive peptides in fermented dairy products have been characterized. These are the specific protein fragment that exhibits their functionality only after release from the parent protein. Depending upon the specific functionality of peptides, bioactive peptides can be categorize as antioxidative, antihypertensive, immunomodulatory, antimicrobial, antithrombotic and mineral binding peptides. These are released during the product manufacturing process either by spontaneous endogenous enzymatic degradation of milk proteins, or with the use of commercial peptidases under controlled hydrolytic conditions. Bioactive peptides can also liberated during gastrointestinal digestion. The generation of peptides involved the endogenous endo and exo peptidases and adequate processing conditions for the enzymes involved to be in active state. On the other hand, bioactive peptides can also be released by the combined proteolytic activity of endogenous and microbial peptidases. Proteolytic microflora linked with the starter and non starter bacteria also contribute to the release of peptides. So far the functionality of the bioactive peptides is still inadequately characterized so have to carry out further study to confirm the functionality.