Abstract

In recent times, the biological activities of enzymatic digests of plant and animal proteins have been investigated and have been shown to exhibit multidirectional effects against microorganisms involved in the pathophysiology of a number of diseases. The present study evaluated the antimicrobial and antioxidant effects of pigeon pea protein hydrolysates. Proteins were hydrolyzed using the enzymes pepsin, trypsin and papain. The resulting hydrolysates were evaluated for antimicrobial activities (using selected bacterial strains) and antioxidant effects using DPPH radicals and ferric ions. All hydrolysates displayed varying antimicrobial activities, with papain hydrolysates showing the broadest specificity against four bacterial strains (Staphylococcus aureus, Actinobacter baumanni, Escherichia coli and Salmonella species). Antioxidant assays indicated that hydrolyates derived from tryptic digestion showed the highest DPPH radical scavenging activity and ferric reducing antioxidant power. These results suggest that the subjection of pigeon pea proteins to enzymatic digestion could yield peptides that can be harnessed to formulate products which could serve as novel alternatives to current therapies in the treatment of infectious diseases.

Key words: Pigeon pea, protein, hydrolysates, pepsin, trypsin, papain, antimicrobial, antioxidant.