Peptides obtained from fermented faba bean seeds (Vicia faba) as potential inhibitors of an enzyme involved in the pathogenesis of metabolic syndrome

The influence of faba bean seed fermentation on the release of bioactive peptides after digestion in gastro-intestinal conditions was investigated. The molecular mass of protein detected by SDS-PAGE was in the range from 6.5 to 97 kDa. The highest degree of protein hydrolysis (98.72%) was noted for protein obtained from seeds fermented for 3 h at 37 degrees C. The hydrolyzate of seeds fermented for 7 days at 30 degrees C was characterized by the highest peptide content (4.78 mg/mL). The highest ACE-inhibitory and antiradical against ABTS(+) activity were noted for a peptide fraction obtained from a sample fermented for 3 days at 30 degrees C (IC50 = 1.01 and 0.99 mg/mL, respectively). The sample obtained after 3-h fermentation at 22 degrees C was characterized by the highest LOX inhibitory activity (IC50 = 0.54 mg/mL). The lowest IC50 value was determined for fractions obtained from seeds fermented for 3 h and 7 days at 37 degrees C, and the value was not significantly different (0.92 and 0.89 mg/mL, respectively). The peptide fraction obtained from seeds fermented for 3 days at 30 degrees C with the highest potential for inhibition of metabolic syndrome development was separated on Sephadex G10 and peptide sequences were identified by LC-MS/MS.