Effects of extraction solvent on wheat bran antioxidant activity estimation

Significant levels of antioxidant activities and phenolic components have been detected in wheat and wheat-based food products, indicating that wheat may serve as an excellent dietary source of natural antioxidants for disease prevention and health promotion. Several solvent systems have been used to prepare antioxidant extracts from wheat and wheat-based food products. This makes it difficult to compare and understand the antioxidant activities of wheat reported from different research groups. The purpose of this study was to evaluate the effects of four selected solvent systems at ambient temperature for 15 h and Soxhlet extraction with absolute ethanol on antioxidant activity measurements. The four solvent systems included 50% acetone (v/v), 70% methanol (v/v), 70% ethanol (v/v), and ethanol, and antioxidant activities were tested using ORAL, radical scavenging activities against stable DPPH. and cation ABTS(.+), and total phenolic content. The results showed that the extracting solvent significantly altered the antioxidant property estimations of wheat bran, and 50% acetone is a recommended solvent for extracting phenolic antioxidants from wheat bran for analytical purpose. (C) 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.