Valorization of pulse by-products through fermentation: a strategy to enhance antimicrobial activity

Pulses are widely consumed, and their industrial processing generates by-products that may contain antimicrobial compounds. While previous studies reported that enzyme-assisted extraction could release antimicrobial peptides from legumes and pulses, this study found no inhibitory activity against four major foodborne pathogens (Listeria monocytogenes, Salmonella enterica, Escherichia coli, and Staphylococcus aureus) in crude hydrolysates. As an alternative, fermentation was explored. Fermentation with Lactiplantibacillus plantarum UPCCO 4932, showed promising results. Fermented by-products such as peas, chickpeas, beans, bean pellets, and bean hulls exhibited a bactericidal effect against L. monocytogenes, reducing its count by more than 3 Log CFU/g. Other by-products showed a bacteriostatic effect, halting pathogen growth during 24 h challenge tests. These findings suggest that controlled fermentation of pulse by-products using selected LAB strains can be an effective valorization strategy. It offers a sustainable way to develop natural antimicrobials, enhancing food safety while reducing agricultural and food processing waste. Optimized fermentation parameters and the use of specific microbial strains like L. plantarum are key to maximizing antimicrobial efficacy in fermented plant-based matrices.