extraction solvent concentration affecting the anthocyanins and other phytochemicals profile and antioxidant properties of bran extracts of pigmented rice cultivars

Different concentrations (100%, 90%, and 80%) of extracting solvent methanol were used to determine antioxidant capacities of seven pigmented rice cultivars bran on the basis of phytochemicals and other antioxidants. tpcs of red-colored bran (zag, kaw quder, and shel kaw) were the highest in 100% methanol, and those of black pigmented bran (samarkand), lightly blackish (kaw kareed) and brown (gull zag, teli zag), were the highest in 80% and 90% methanol. the higher avonoid contents in non-pigmented gull zag and teli zag resulted from luteolin-7-o-glucoside, quercetinhexoside, apigenin-7-oglucoside, quercetin-3-o-galactoside, apigenin and (epi)catechin rather than anthocyanins in pigmented rice. higher anthocyanin contents of extracts in lower methanol concentration resulted from higher percentage of cyanidin-3-o-rutinoside, pelargonidin-3-o-diglucoside, and cyanidin-3-o-galactoside. the antioxidant activity showed a similar trend in which the pigmented cultivars showed higher antioxidant activity in 100% methanol, except redcolored shel kew with higher value in 90% methanol, while, among the light colored brown rice brans, kaw kareed showed higher activities in 80% methanol and teli zag in 90% methanol.