Peptidomics profiling and biological activities of grape pomace protein hydrolysates
Franziska Knuf, Rita Caspers-Weiffenbach, Andreas Schieber, Ariel Fontana
Abstract
Grape pomace protein isolate was hydrolysed by Alcalase, Flavourzyme and Protease either individually or in combination to produce hydrolysates with antihypertensive and antimicrobial properties. The degree of hydrolysis (DH) ranged between 22 and 52 % for Protease and Flavourzyme, respectively. Among all treatments, hydrolysates prepared using Flavourzyme exhibited the highest angiotensin-converting enzyme inhibitory (ACEi) activity, with an IC 50 value of 91 μg/mL. The peptidomics analysis revealed that the peptides identified in Flavourzyme hydrolysate presented molecular features compatible with its bioactivity, like a high density of ACEi sequences per peptide. The hydrolysates were also able to inhibit the growth of Escherichia coli in a range between 9 and 54 % for Alcalase and Alcalase + Flavourzyme, respectively. Peptides in the most active hydrolysate evidenced a high occurrence of proline residues, which is a structural feature of some antimicrobial peptides. • Hydrolysis of grape pomace proteins with different enzymes was optimized • Grape pomace hydrolysates evidenced antihypertensive and antimicrobial properties • Sequences of potential bioactive peptides were identified by peptidomics • Bioactivity of identified peptides was predicted based on the amino acids composition