Cereal Chem 68:267-271   |  VIEW ARTICLE

Stabilizing Brown Rice Products by Aqueous Ethanol Extraction.

E. T. Champagne, R. J. Hron, Sr., and G. Abraham. Copyright 1991 by the American Association of Cereal Chemists, Inc. 

This article describes extraction processes using aqueous ethanol (EtOH) (95%, v/v) for producing stabilized brown rice and brown rice flours. The effects of EtOH extraction on brown rice composition, appearance of kernel surface, bacterial and mold populations, and storage stabilities of brown rice kernels and flours (prepared from extracted kernels) were examined. Less than 3% of the oil was removed from brown rice kernels extracted with EtOH at room temperature (RT) approximately 24 C), whereas extraction at 70 C removed 15% of the oil. Thiamin retention was 91 and 37% in kernels extracted with EtOH at RT and 70 C, respectively. Little or no loss of protein, dietary fiber, carbohydrates, or minerals occurred in the extracted kernels. EtOH extraction decreased the bacterial population of the rice to very low levels and, at RT or 70 C, stabilized brown rice kernels to lipolysis. Only flour prepared from kernels extracted with EtOH at 70 C was stable to lipolysis. Brown rice kernels extracted with EtOH at 70 C were more susceptible to oxidative rancidity, probably because the hot alcohol disturbed the caryopsis coat.