Composition, industrial processing and applications of rice bran γ-oryzanol

Rice bran oil (RBO) (20-25 wt% in rice bran) is a unique rich source of commercially-important bioactive phytochemicals, most of them of interest in nutrition, pharmacy and cosmetics. The unsaponifiable constituents of RBO include mainly tocols (vitamin E, 0.10-0.14%) and gamma-oryzanol (esters of trans-ferulic acid with sterols and triterpenic alcohols, 0.9-2.9%). The following topics concerning gamma-oryzanol are reviewed: analytical methods for characterisation and determination; influence of genetic and environmental factors on the composition of rice bran: extraction approaches, including supercritical CO2 and subcritical water: and biomedical and industrial applications, including food and pharmaceuticals. Concentration ranges of gamma-oryzanol, tocopherols and tocotrienols found in rice bran and RBO from different varieties and geographical areas are summarised. This review focuses on the 2003-2008 period, where an average of 13-14 references per year were published; however, some relevant work reported during the 19982002 period is also briefly commented upon. (C) 2009 Elsevier Ltd. All rights reserved.