Simultaneous hydrolysis of proteins from different sources to enhance their antibacterial properties through the synergistic action of bioactive peptides

Antimicrobial peptides have been identified as possible substitutes for chemicals used as drugs or food preservatives, owing to their high specificity, easy degradability in the environment, and low toxicity. In the current study, three different protein sources (viz., soy protein isolate [SPI], bovine whey protein [BWP], and egg white protein [EWP]) were hydrolyzed using Flavourzyme® 500L, individually or in binary/ternary mixtures, to verify the antibacterial activities of the hydrolysates obtained. The most adequate formulations to inhibit the tested bacterial strains were 1) the ternary mixture of SPI, BWP, and EWP in equal proportions for Escherichia coli ATCC 11229, 2) all binary mixtures of the protein hydrolysates for Salmonella enterica serotype Choleraesuis ATCC 14028, and 3) the binary mixture of SPI and BWP for Staphylococcus aureus ATCC 6538, which decreased the bacterial growth by ≥19%, ≥15%, and ≥48%, respectively. The enzymatic process proposed in our study proved to be a promising alternative for producing protein hydrolysates with high potential bioactivity, by simultaneously hydrolyzing mixtures of different protein sources to obtain peptides that could act synergistically to inhibit pathogenic bacteria.