Rice Bran Phytosterols of Three Widespread Iranian Cultivars

Rice bran sterols have antioxidant activity as well as physiological and biological effects. Because of these benefits, the aim of this study is evaluating the quantity and quality of Iranian rice bran sterols. Three widespread Iranian rice cultivars (Khazar, Hashemi, and Alikazemi) were used for determination of their sterol contents. Two methods of sample preparation were compared and the better one was used in this work. Rice bran samples were saponified directly after acid hydrolysis. Unsaponified materials were extracted, purified by solid phase extraction, silylated, and their sterol fractions determined by GC-MS. The sterol composition (in mg kg-۱ bran) of three cultivars (Khazar, Alikazemi, and Hashemi) were ۱,۳۳۰.۶۹, ۱,۲۷۹.۹۵, ۱,۳۱۳.۱۷ β-sitosterol; ۷۴۷.۵۲, ۶۹۶.۰۵, ۷۵۶.۸ campesterol; ۱۱۲.۸, ۱۱۵.۳۶, ۱۱۴.۲۴ Δ-۵-avenasterol, ۳۸.۹۱۲, ۳۳.۰۸, ۳۸.۲۴ Δ-۷-avenasterol; ۸.۰۵, ۷.۰۷, ۷.۵۶c holesterol; ۴.۲۰, ۳.۹۹, ۴.۲۳ brassicasterol; and ۲,۷۲۲.۰۱۶, ۲,۷۰۶.۱۷۶, ۲,۷۱۷.۶۸ total sterols, respectively. The results showed that there were no significant differences between the individual and total sterol contents of these three cultivars (P> ۰.۰۵), except campesterol, β-sitosterol, and Δ-۷-avenasterol. The highest and lowest sterols were ß-sitosterol and campesterol.

Keywords:

Phytosterols , Plant sterols , Rice bran , Sterol content determination