Proteolytic activity of Lactic Acid Bacteria as a tool for development of novel functional food

Modification of the molecular structure of food proteins with enzymes is an attractive way of improving the functional and nutritional properties of these proteins. Today various enzymes are applied to food proteins for the manufacture of new and valuable products. Protein structure is modified to improve solubility, emulsification, gelling and foaming properties. Proteolytic activities of lactic acid bacteria (LAB) are responsible for producing biologically active peptides in different fermented food products. Proteolytic system of LAB is consisted of a cell wall-bound proteinase and a number of distinct intracellular peptidases. Our studies focused on potential of probiotic bacteria such as LAB for producing bioactive substances.Several strains of LAB isolated from fermented dairy products were investigated for their proteolysis activity Our studies showed the release of ACE-inhibitory, antioxidant and antimicrobial peptides during the fermentation of dairy products. The results indicated a good correlation between degree of hydrolysis and biological activity. LAB have the potential to be used as a starter culture in the manufacture of functional food products. One of the other applications of proteases is to decrease the risk of allergenicity when cow’s milk is used as a substitute for human milk. Hydrolyzing of ß-Lactoglobulin by enzymatic activities during fermentation can reduce allergenicity. Also our future studies will focus on enzymatic activity of isolated LAB to decrease the allergenicity of gluten in sour dough.

Keywords:

LAB , Proteolytic activity , Bioactive peptide , Allergenicity , Functional Food