Phytosteryl ferulates (γ-oryzanol) have been shown to exhibit antioxidative and cholesterol-lowering activities. Methods proposed for the analysis of γ-oryzanol in rice require laborious clean-up steps. In the present study an approach based on on-line coupled liquid chromatographygas chromatography (on-line LC-GC) was developed for the simultaneous determination of γ-oryzanol contents and steryl ferulate distributions in rice extracts without previous purification. The method developed was applied to investigate the natural variation of γ-oryzanol contents and steryl ferulate distributions in European brown rice. Genetically modified rice lines and their corresponding parental lines were compared and differences between the lines were assessed in the light of natural variation. In addition, the influence of rice flake production on γ-oryzanol content and steryl ferulate distribution was investigated. Commercial enzymes and artificial gastrointestinal fluids were used to study the hydrolysis of steryl ferulates in-vitro.
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