Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/8/2002
Publication Date: 6/1/2002
Technical Abstract: The lipids of rice bran are potentially valuable constituents. However, currently because of its oxidative instability, rice bran is primarily used for animal feed. In 2000, a germplasm collection consisting of 213 divergent rice accessions was grown in Beaumont, TX and evaluated for total lipid content and fatty acid composition. Bran oil content varied strongly, ,ranging from 16.8 percent to 28.3 percent w/w. Major fatty acids of bran oil were palmitic, oleic and linoleic acids, which were in the ranges of 13.5 to 22.5 percent, 36.1 to 51.5 percent and 26.9 to 40.5 percent, respectively. The ratio of saturated to unsaturated fatty acids ranged from 0.20 to 0.36, being strongly related to the palmitic acid content (r2 equals 0.98). The variation found suggests it is possible to select for both oil content and fatty acid profile in rice. Two different alternatives are proposed for increasing bran utilization: breeding for reduced oil content and low proportion of polyunsaturated fatty acids to increase rice bran stability, and breeding for higher bran oil content and improved fatty acid composition for bran oil production. Breeding techniques such as chemical mutagenesis or genetic transformation may be required for designing rice bran oils containing extreme proportions of certain fatty acids.