Proteolytic activity of Lactobacillus strains on soybean proteins

•Lactobacillus strains were able to hydrolyze soy proteins.•α´subunit of β-conglycinin were the most degraded fraction.•Peptidase activities were evaluated with different substrates.•Lactobacilli strains showed different enzyme specificity on soy proteins.

The capacity of Lactobacillus strains for degrading soy proteins was evaluated. The hydrolytic action was monitored by SDS-PAGE and reverse phase-HPLC analyses. Peptidase activities were also determined using synthetic chromogenic substrates. All assayed strains were able to hydrolyze α'-subunit of β-conglycinin while for the other fractions the degree of degradation was strain-dependent. The pattern of peptides produced from soy proteins hydrolysis differed amongst the lactobacilli studied, suggesting different proteolytic enzyme specificities.