These occur mainly in the form of fatty acyl esters,
ferulic acid esters known as γ-oryzanol, and free sterols. Of
these sterols, γ-oryzanol is considered important for several reasons.
The ferulic acid portion of γ-oryzanol has antioxidant activity,
and thus γ-oryzanol is believed to contribute to the high stability
of rice bran oil [5]. Purified γ-oryzanol has been investigated
as a potential lipophilic antioxidant for use in foods and
cosmetics. Rice bran oil spreads were enriched in total sterols
(40–58% higher) compared to the crude rice bran oil, but the enriched
components were mainly composed of free sterols and
fatty acyl esters, while only 20–24% of the γ-oryzanol partitioned
into the rice bran oil spreads.