Association of genotype and preparation methods on the antioxidant activity, and antinutrients in common beans (Phaseolus vulgaris L.)

Three bean genotypes were selected in order to be evaluated, being IAPAR-81 (IAP), Uirapuru (UI) and BAF 55 (BAF). The samples were: raw (R), cooked without soaking (CWS), cooked with soaking water (CWSW) and cooked without soaking water (COSW). For the antioxidant activity, total phenolics, tannin and phytate analysis, the broths were separated from the grains and the soaking water separated from the COSW sample was analyzed. The CWSW and COSW grain samples showed higher antioxidant potential in the three genotypes (IAP: 0.037 and 0.039; UI: 0.035 and 0.040; BAF: 0.040 and 0.047, respectively). There were losses of total phenolics, tannin and phytate in all samples of the cooked beans demonstrating the importance of consumption and use of the cooked broths. The CWS was the preparation that preserved the majority of the nutrients in the grains, except for the antioxidant activity. In the broth, BAF 55 showed higher levels of tannin and phenolic compounds in all preparations. The analysis of the raw bean is important to know the nutritional value of the food, but the common bean is consumed cooked which modifies its characteristics as well as the availability of the nutrients to be absorbed.

► Three bean genotypes were evaluated according antioxidant activity, total phenolics, tannin and phytate. ► Samples: raw, cooked without soaking, cooked with soaking water and cooked without soaking water. ► The broths, the grains and the soaking water were analyzed. ► Cooked without soaking was the preparation that preserved the majority of the nutrients in the grains. ► There were losses of total phenolics, tannin and phytate in all samples of the cooked beans.