Encapsulation of Bacillus subtilis Cells for Production of Whey Protein Hydrolysates

Abstract

Bacillus subtilis biomass was encapsulated in 2 biopolymeric membranes to evaluate the enzyme hydrolysis of whey protein and the functional characteristics of the obtained products. The encapsulates of membranes contained composite gel of sodium alginate and chitosan supplied with polyethylene glycol or glutaraldehyde for improving the mechanical properties of the composite. Morphology, porosity, water retention and biomass proliferation of membranes were analyzed. Protease activity from encapsulated B. subtilis was evaluated by the kinetic of protein hydrolysis for 8 h. Quality of hydrolysates was analyzed according to their functional properties. Conventional hydrolysis by commercial neutrase and free biomass of B. subtilis were used as control. Alginate-chitosan-polyethylene glycol composite gave the best results of bacterial encapsulation. Functional properties of the whey protein hydrolysates were comparable with those for products obtained after the action of neutrase and free microbial biomass. In addition, the enzyme activity remained after 5 cycles of hydrolysis. Thus, encapsulating microbial biomass could be an economic alternative of biocatalytic process to produce functional whey products.