Chemical changes and antioxidant activities of heated whole barley extracts

Chemical profiles of ethanolic (70%) and aqueous extracts of whole barley heated at 150, 190, and 230 °C were analyzed by GC-MS and their antioxidant properties were studied in vitro, in bulk oil, or in an oil-in-water (O/W) emulsion systems. More chemicals were detected in the ethanolic extract than in the aqueous extract from heated barley; heating decreased the contents of detected chemicals. Organic acids, mono- and di-saccharides, sugar alcohols, and glycerol were the major chemicals detected in both the extracts. Ethanolic extracts possessed higher in vitro antioxidant activities than the aqueous extracts. However, this trend was not clearly observed in the bulk oil and O/W emulsion. For O/W emulsions, ethanolic extracts obtained following heating at 150 °C prevented lipid oxidation better than others. Therefore, heat treatment at 150 °C is recommended to enhance the antioxidant activities of whole barley.