67C-19 |
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K. T. HWANG1, J. E. Kim, Y. J. Soh, H. O. Lee, S.-B. Kim1, and C. L. Weller5. (1) Food Science & Human Nutrition, Chonbuk National University, Jeonju, Jeonbuk, 561-756, South Korea, (2) Department of Biological Systems Engineering, University of Nebraska Lincoln, 210 L.W. Chase Hall, Lincoln, NE 68583-0726 Policosanols are a mixture of primary long-chained alcohols and have been known to have various physiological activities. Recently grain sorghum was found to be a good source of policosanols, which can be recovered from the surface of the grains. Rice is the principal staple in Asia. Bran is removed from sorghum and rice before use as food. Massive availability of rice and rice bran in Korea led us to determine whether rice and rice bran are potential sources of policosanols, compared to sorghum and sorghum bran. The objective was to determine contents and profiles of policosanols extracted from rice, rice bran, sorghum and sorghum bran produced in Korea. Long-chained lipids (LCL) were extracted from brown rice (BR), unpolished (UGS), polished grain sorghum (PGS), rice bran (RB) and sorghum bran (SB) using hexane by refluxing, cold-precipitation, and filtration. Composition of the LCL was identified using TLC. Contents of policosanols in the LCL were analyzed using HPLC. Policosanol fraction of the LCL collected from the HPLC column was derivatized to trimethylsilyl ethers, followed by analyzing policosanol profiles using GC. Yields of LCL from BR, UGS, PGS, RB and SB were 33, 223, 37, 1900 and 1000 mg/100 g (db), respectively. Policosanols in the LCL from BR, UGS, PGS, RB and SB comprised 5.7%, 33%, 29%, 4.1% and 33% (w/w), respectively. Fatty alcohols C26:0, C28:0 and C30:0 were 7.1%, 12.7% and 29.3%, respectively, in the policosanols from BR; 9.2%, 45.5% and 30.2% from UGS; and 14.6%, 45.6% and 27.3% from PGS. Policosanols in RB contained 8.7% C26:0 and 6.0% C28:0 and the rest was 12.5% C20:0, 55.9% C22:0 and 17.0% C23:0, while policosanols in SB constituted 15.8% C26:0, 45.0% C28:0 and 25.1% C30:0. The results suggest that rice and rice bran are not likely to be good sources of policosanols due to low levels and poor composition in policosanols, compared to sorghum and sorghum bran.
Session 67C, Food Chemistry: Food analysis, irradiation and toxicology
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