Phenolic compounds and antioxidant activity of two bean cultivars (Phaseolus vulgaris L.) submitted to cooking

Abstract

Phenolic compounds and antioxidant activity of two bean cultivars (Phaseolus vulgaris L.) submitted to cooking Compostos fenólicos e atividade antioxidante de duas cultivares de feijões (Phaseolus vulgaris L.) submetidos à cocção AbstractThe 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. ResumoO feijão (Phaseolus vulgaris L.) é uma leguminosa que, além de ser fonte de nutrientes, possui compostos fenólicos que atuam como antioxidantes. O presente estudo teve por objetivo a determinação de compostos fenólicos e taninos de duas cultivares de feijão (Phaseolus vulgaris L.): carioca biofortificado (Pontal) e comum (comercial). Averiguou-se ainda a atividade antioxidante dos compostos fenólicos e de suas frações, por meio dos métodos DPPH e ABTS. O tratamento térmico diminuiu os teores de compostos fenólicos, taninos e a atividade antioxidante dos feijões. A cultivar Pontal apresentou maiores teores de compostos fenólicos, mesmo após a cocção. Para as amostras de feijão cozido, observou-se maior atividade antioxidante para o feijão comercial pelo método DPPH. Quanto às frações fenólicas, observou-se decréscimo nos valores de atividade antioxidante por DPPH após o cozimento dos feijões, exceto para a fração 6 da cultivar Pontal e para fração 3 do feijão comercial. Para a fração 4, em ambas cultivares não foram observadas diferenças significativas na atividade antioxidante pelo método ABTS após tratamento térmico. Palavras

Effects of different hydration treatments on technological, physical, nutritional, and bioactive parameters of lentils

“…Besides anthocyanins content, antioxidant activity determined by the ABTS method is reduced by the cooking process. These results corroborate those of Silva et al 46 who reported that cooking beans reduced the antioxidant capacity compared to that of the grain in natura.…”

Human bioavailability of phenolic compounds found in common beans: the use of high-resolution MS to evaluate inter-individual variability

“…The cooking process was responsible for changes in the beans' accessible compounds. A reduction in the TPC (-61 %) was detected after cooking, and it was comparable to the TPC value described for the pinto cooked beans (40) , representing 63-77 % of the TPC determined in the raw seeds of pinto beans (41) . Most of the studies on beans are still focused on the TPC and only a few ones (41,42,(44)(45)(46)(47)(48)(49) on the individual phenolic compounds.…”

“…As far as we know, this work is the most complete study that has been performed to evaluate the bioavailability of phenolic compounds from cooked common beans, using UPLC-Q-TOF-MS. Based on the phenolic content of the three Portuguese studied varieties, the Portuguese common bean variety Moleiro was chosen as the variety with the highest TPC ( Table 1). Despite of the morphological differences in the seed colour, the TPC of Moleiro raw beans, 3•36 (SD 0•11) mg GAE/g of raw seed DW (2•91 (SD 0•09) mg GAE/g of raw seed fresh weight (FW)), characterised by light brown seeds, was within the range of values described by Heimler et al (43) for light green, white and yellow varieties (1•17-4•40 mg GAE/g of raw seed FW) and by Silva et al (40) for pinto varieties, characterised by cream coloured seeds with speckles ( Table 2).…”

Characterization of Soaking Process’ Impact in Common Beans Phenolic Composition: Contribute from the Unexplored Portuguese Germplasm

“…These results may be attributed to the extraction of soaked coats and soaked cotyledons, performed separately after the soaking process. Such procedure allowed a higher extraction rate of the free phenolic compounds present in coats fraction, since cotyledons removal could eliminate some phenolic-protein interactions [47]. For this reason, despite the phenolic compounds’ loss into the soaking water, an overall comparison of common beans TPC in whole flour and in soaked beans (calculated as the sum of the TPC determined, separately, in both soaked fractions, coats and cotyledons) showed that at least 51% of the TPC determined in non-soaked seeds was preserved after soaking, which contradicts the high decrease, −73%, in the TPC of soaked beans reported by Faller & Fialho (2012) [48].…”