Fatty acids and all‐ trans ‐β‐carotene are correlated in differently colored rice landraces

A set of 54 rice landrace samples was compiled from various Asian countries, including six red/brownish and eight black/purple varieties. Brown rice samples were analyzed for lipid content and fatty acid profile, as well as all‐ trans ‐β‐carotene content. Black/purple varieties were found to be higher in crude lipid content than the red/brownish and colorless varieties. They also had a higher β‐carotene content than the other two color classes. The highest β‐carotene content determined was 0.22 mg kg −1 . Black/purple varieties tended to have a higher proportion of saturated fatty acids in their lipid fraction and a lower proportion of unsaturated fatty acids. The differences were statistically significant ( P < 0.05) for oleic acid, which accounted for 42.1% of the lipid fraction in black/purple varieties and for 45.3% and 46.3% in red/brownish and colorless varieties, respectively. β‐Carotene content showed a significantly positive correlation with the crude lipid content ( P < 0.001) and the content of saturated fatty acids ( P < 0.001) on a dry matter basis. However, it was not correlated with the unsaturated fatty acids content on a dry matter basis. Within the total lipid extract, β‐carotene showed a significantly positive correlation with the proportion of saturated fatty acids ( P < 0.01), especially palmitic acid ( P < 0.01), and a significantly negative correlation with unsaturated fatty acids ( P < 0.001), especially oleic acid ( P < 0.01). Copyright © 2005 Society of Chemical Industry