Comparative analysis of rice bran and sesame protein hydrolysates in inhibiting foodborne pathogens: efficacy against Escherichia coliO157:H7 and Listeria monocytogenes

Abstract

SummaryThis study explores the antibacterial potential of hydrolysates derived from rice bran protein (RBP) and sesame protein (SP) against Escherichia coli O157:H7 and Listeria monocytogenes. RBP and SP were hydrolysed by protease from Bacillus licheniformis (labelled as RBPH‐B and SPH‐B) and α‐chymotrypsin (denoted as RBPH‐C and SPH‐C), and subsequently fractionated into four molecular weight (MW) categories: F1 (>100 kDa), F2 (10–100 kDa), F3 (1–10 kDa), and F4 (<1 kDa). The antibacterial activities of these hydrolysates and their fractions were systematically evaluated. The results indicated that RBPH‐B and RBPH‐C, along with their fractions, exhibited notable efficacy against L. monocytogenes. Conversely, both SPH‐B, SPH‐C, and their fractions showed pronounced antibacterial activities against both pathogens. Notably, lower MW fractions (SPH‐B, SPH‐B‐F2, and SPH‐B‐F3) demonstrated superior antibacterial properties, effectively reducing bacterial populations to below detection limits (≥6 log CFU mL−1) at a concentration of 100 mg mL−1. Further analysis revealed that SPH‐B‐F3 markedly reduced the reaction time required to inhibit or eliminate E. coli O157:H7 and L. monocytogenes, with comparable times of 6 and 4 h, respectively. These findings highlight the potential application of specific SPH‐B fractions as antibacterial agents in the food industry.