ANTIOXIDANT PROPERTIES OF PEPTIDES FROM PLANT SOURCES

Introduction. Bioactive peptides from plant sources are a promising area of modern biotechnology, and their scope of application is expanding every year. One of the parameters valued in such peptides is their antioxidant properties. In our study, we analyzed the antioxidant properties of peptides from unpopular but promising sources - common bean husks and coffee grounds. Methods. We used two approaches to obtain peptides, namely, the method of acetic acid hydrolysis (AAH) of protein molecules present in the raw material, as well as the method of extraction of native peptides in combination with multistage precipitation of molecules with a molecular weight below 5 kDa. In this study, we evaluated the total antioxidant activity using the ABTS-+ cation radical and also investigated the level of TBA-active products in the reaction of ferric/ascorbate-dependent oxidation of Tween-80 in the presence of the obtained peptide fractions. Results. According to the results obtained, peptides from coffee grounds obtained by both methods had a higher level of antioxidant activity compared to peptides from bean husks. Thus, for the peptides obtained by the AAH method, the level of antioxidant activity was 75 ± 4 % and 39 ± 3 %, respectively. Whereas, for native peptides obtained by extraction, this figure was 68 ± 3 % and 55 ± 5 %, respectively. The peptides from coffee grounds obtained by AAH also had a noticeable inhibitory effect on the intensity of accumulation of TBA-active products, while the peptides from bean husks obtained by a similar method had a less pronounced effect. Conclusions. Our results suggest that coffee grounds can be a valuable source of peptides with antioxidant activity. At the same time, despite the fact that the antioxidant potential of peptides from bean husks is significantly lower, the use of this raw material may have a significant economic basis, since this plant material is an element of legume processing waste in the food industry, in particular.