Identification of potential inhibitory peptides of enzymes involved in the metabolic syndrome obtained by simulated gastrointestinal digestion of fermented bean (Phaseolus vulgaris L.) seeds.

The aim of this study was to determine the conditions of bean fermentation carried out by Lactobacillus plantarum to obtain biologically active peptide fractions after in vitro digestion. The results suggest that optimum process conditions should be selected according to the specific activity of peptides. Only a fraction with a molecular mass of 3.5-7kDa obtained after fermentation at 22°C for 3h had α-amylase inhibitory activity. The optimal fermentation conditions for bean seeds to release peptide fractions with a molecular mass of 3.5-7.0kDa and the highest lipase or ACE inhibitory activity (IC50 1.19 and 0.28mg mL-1, respectively) were determined as 30°C and 3days. The fractions with the highest inhibitory activity were identified by LC-MS/MS and the sequences of the peptide derived from bean proteins were determined as INEGSLLLPH, FVVAEQAGNEEGFE, SGGGGGGVAGAATASR, GSGGGGGGGFGGPRR, INEGSLLLPH, GGYQGGGYGGNSGGGYGNRG, GGSGGGGGSSSGRRP, and GDTVTVEFDTFLSR.