Content of phenolic compounds and antioxidant capacity of varieties of bean sowed in Zacatecas

Abstract

A total of nine varieties of bean from Zacatecas, the main producer of this legume in Mexico, were evaluated. The phenolic compounds were determined as anthocyanins, flavonoids, tannins, and total phenolics, as well as their antioxidant capacity by the DPPH method. The anthocyanins, flavonoids, and tannins content varied from 0.22 mg to 3.45 mg of cyanidine-3-glucoside equivalents (C3GE)/100 g, 16 mg to 103 mg of catechin equivalents (CE)/100 g, and 474 mg to 587 mg of catechin equivalents (CE)/100 g, respectively. On the other hand, the total phenolics concentration varied from 67 mg to 204 mg of gallic acid equivalents (AGE)/100 g. Most total phenolics (64% to 93%) and total flavonoids (55% to 81%) were found in the bound fraction. The antioxidant capacity levels were from 243 μmol to 1282 μmol of trolox equivalents (TE)/100 g. The varieties Flor de Junio and Negro San Luis presented the highest values of total phenolics, flavonoids, and antioxidant capacity.