Abstract
The common bean (Phaseolus vulgaris L.) is a source of nutrients and contains phenolic compounds that act as antioxidants. The aim of the present study was to determine the phenolic compounds and tannins in two bean cultivars (Phaseolus vulgaris L.): the biofortified carioca bean (Pontal) and the common bean (commercial). The antioxidant activity of the phenolic compounds and their fractions was also measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods. The thermal processing decreased the phenolic compounds, tannins and the antioxidant activity of beans. The Pontal cultivar exhibited higher levels of phenolic compounds even after cooking. For cooked beans, higher antioxidant activity was observed in the commercial beans by the DPPH method. Regarding to the fractions, in general, lower values of antioxidant activity by DPPH were observed for beans after cooking, except for fraction 6 of the Pontal bean and fraction 3 of the commercial bean. For fraction 4 no significant differences were observed by the ABTS method for both cultivars after thermal processing.
Keywords:
Legumes; DPPH; ABTS; Thermal treatment; Pontal bean; Common bean