Comparative analysis of the characteristics and content of γ-oryzanol in 19 Chinese brown rice cultivars

Abstract

The composition and content of γ-oryzanol significantly influenced its biological activity. The contents of γ-oryzanol in 19 Chinese brown rice (Oryza sativa L.) cultivars were quantified and characterized using high-performance liquid chromatography/mass spectrometry. The total content of γ-oryzanol in these 19 Chinese brown rice cultivars ranged from 19.37 to 232.2 mg/100 g, with an average of 76.23 mg/100 g. Five specific steryl ferulates were identified. Cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, and β-sitosteryl ferulate comprised approximately 82 % of the total γ-oryzanol content, while campesteryl ferulate and stigmastanyl ferulate constituted the remaining 18 %. Japonica and glutinous rice exhibited similar γ-oryzanol contents, which were significantly different from those of indica rice. No significant difference was observed in the total γ-oryzanol content between the short-grain and long-grain rice. However, there were significant differences in the steryl ferulates. Both latitude and longitude significantly influenced the γ-oryzanol content, and longitude had a more pronounced effect than latitude. Apart from the lack of correlation between cycloartenyl ferulate and β-sitosteryl ferulate, significant correlations were observed among the contents of the other steryl ferulates. This study offers valuable insights to scientifically assess the nutritional value of Chinese brown rice, guide the breeding of varieties and inform high-quality cultivation practices.