Antioxidant properties of common bean (<i>Phaseolus vulgaris</i>) husk-derived peptides

Protein hydrolysates and plant peptide extracts can become next-generation natural, eco-friendly food supplementary with a wide range of bioactive features. From folk medicine, it is known about the aqueous extract of the common bean (Phaseolus vulgaris) and its exceptional treatment features. Various abilities of peptides from P.vulgaris have been closely studied in recent years, but another component of “bean pod tea” – husk hydrolysates has not been studied at all. Therefore, this study aimed to obtain and perform a primary analysis of peptides from common bean husks using two methods-acidic hydrolysis and perchloric acid extraction. The first method was based on the hydrolysis of protein-rich plant extracts by acetic acid, allowing to obtain hydrolysis-derived peptides, while extraction by perchloric acid resulted in retrieving of native endogenous peptides. Using Spectrophotometry and size-exclusion chromatography, the study showed that the perchloric acid extraction method allows the extraction of peptides with MW 205-590 Da, which have moderate OH-scavenging activity. Peptides obtained by acidic hydrolysis (192-610 Da) had significantly higher levels of DPPH-scavenging and FRAP activities (14 ± 0,68 % and 27 ± 1,12 % respectively). Therefore, peptides from P. vulgaris bean husk have antioxidant activity, and to elaborate on these findings, the antimicrobial and inhibitory activities of these peptides should be tested in future studies.