The mixtures were thoroughly vortex-mixed and incubated at room temperature for 30 min. A decrease in the absorbance was determined at 517 nm against the blank (methanol–water, 8:2 v/v) using a UV–VIS spectrophotometer (Shimadzu UV-1601PC, Japan). The results were expressed as μmol of Trolox equivalents per hundred grams of the sample (μmol TEAC/100 g sample).