Detailed characterization in nutrients and phytochemicals with antioxidant activities of 26 kidney beans was performed. The kidney beans contained high levels of dietary fiber (29.32-46.77%), resistant starch (9.16-18.09%) and protein (22.06-32.63%) but low levels of lipid (1.05-2.83%) and sugars (1.55-9.07%). The monosaccharide composition of soluble fiber was dominated by arabinose, galactose, mannose and galacturonic acid. The ratio of essential amino acid to the total amino acid was ranged from 0.29 to 0.36. The predominant fatty acid was polyunsaturated fatty acids, accounting for 47.54-67.26% of total fatty acids. The total tocopherol content was in the range of 12.83-68.35 μg/g, predominantly γ-tocopherol, followed by δ-tocopherol. In addition, certain levels of total phenolics and flavonoids with respective values of 0.25-3.79 mg gallic acid equivalent/g dry weight and 0.19-7.05 mg rutin equivalent/g dry weight resulted in significant antioxidant activities. And a good correlation was observed between TPC and FRAP values (R2 = 0.8030). The results indicated that kidney beans are excellent sources of health-promoting compounds.
Keywords: Antioxidant activities; Kidney beans; Nutritional composition; Phytochemicals.
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