Phenolic Content and Antioxidant Properties of Bran in 51 Wheat Cultivars

Abstract

ABSTRACTWhole‐grain‐based diets have been suggested to reduce the incidence of cardiovascular disease and colon cancer. Phenolic compounds, most of which are present in the wheat bran, may be one of the factors contributing to whole‐grain health benefits. We measured the free, bound, and total phenolic content and antioxidant activity in the bran of 51 wheat cultivars belonging to eight Western Canadian spring wheat market classes grown in a replicated trial at Saskatoon, Saskatchewan, Canada. The free phenolic (extracted with 80% v/v aqueous ethanol) content ranged from 854.1 ± 265.1 to 1,754.9 ± 240.3 μg/g of bran gallic acid equivalent (GAE). Saponification followed by a liquid‐liquid solvent extraction released bound phenols ranging from 2,304.9 ± 483.0 to 5,386.1 ± 927.5 μg/g of bran GAE, contributing 66–82% of the total wheat bran phenolic content. Total phenolic content ranged from 3,406.4 ± 32.3 to 6,702.7 ± 19.6 μg/g of bran GAE, with the average being 5,197.2 ± 804.9 μg/g of bran GAE. Antioxidant activity ranged from 11.86 ± 2.59 to 20.12 ± 0.51%, while the overall average was 15.6 ± 2.2%. Based on varietal means, antioxidant activity correlated with free, bound, and total phenolic content (r = 0.8, P < 0.05).