Policosanol Contents and Composition of Grain Sorghum Kernels and Dried Distillers Grains

Cereal Chern. 81(3):345-349 Grain sorghum can be a major source of policosanols, long-chained alcohols, that have beneficial physiological activities. Sorghum dried distillers grains (DDG), a by-product of ethanol production from grain sorghum. contain a large amount of policosanols. Content and composition of policosanols in long-chained lipids extracted from grain sorghum kernels and DDG were determined. Long-chained lipids were extracted using hot hexane or hot ethanol. The major components of the long-chained lipids extracted from grain sorghum kernels. as determined using HPLC were policosanols (37-44%), aldehydes (44-550/c), and A considerable amount of wax-like material (:::::0. 2 o/c , w/w. db) can be extracted from whole kernels of grain sorghum (Weller et al 2000). The chemical composition of this material has been reported sporadically and without consensus over the last half century (Bunger and Kummerow 1951; Cannon and Kummerow 1957; Dalton and Mitchell 1959; Bianchi et al 1979; Avato et al 1990; Seitz 1997). Recently, Hwang et al (2002a) confirmed that the major components of the wax-like material were long-chained aldehydes, alcohols, and acids. Bianchi et al (1979) and Avato et al (1990) previously reported that these components were mainly saturated 28and 30-carbon compounds. Only a small amount of wax esters, a traditional wax component, was contained in the wax-like material. Therefore. long-chained lipids may describe the material more appropriatel y. Annual production of grain sorghum in the United States is 1020 million metric tons. About 12% of the grain sorghum produced in the United States is used for ethanol production (Stan Fury, National Grain Sorghum Producers Director, personal communication). One of the by-products from the ethanol production is dried distillers grains (DDG). Sorghum DDG, in which little, if any, starch remains after ethanol production, still contains lipid and lipidrelated materials. It is assumed long-chained lipids are a part of the lipid materials; however, their presence has never been reported. Policosanols are a mixture of primary long-chained alcohols and are commercially available as nutritional supplements containing mostly octacosanol (28:0), triacontanol (30:0). hexacosanol (26:0). and dotriacontanol (32:0). They have been produced from sugar cane. beeswax, and cereal germs. The alcohols in the long-chained lipids extracted from grain sorghum discussed above are also policosanols. Policosanols reportedly have physiological activities such as improving lipid levels in the blood (Aruzazabala et al 1994; Kato et al 1995; Gouni-Berthold and Berthold 2002), reducing platelet aggregation (Aruzazabala et al 1996), improving exercise performance of coronary heart disease patients (Sttisser et al 1998), and increasing muscle endurance (Kabir and Kimura 1995). 1 Dept. of Food Science and Human Nutrition. and Institute for Molecular Biology and Genetics. Chonbuk National University. Jeonju. Jeonbuk. 561-756. Korea. 2 Department of Biological Systems Engineering. University of Nebraska. Lincoln. NE 68583-0726. 3 Corresponding author. Phone: 402-472-9337. Fax: 402-472-6338. E-mail: cwellerl @unl.edu -I Department of Food Science and Technology. University of Nebraska. Lincoln. NE 68583-0919. 5 Industrial Agricultural Products Center. University of Nebraska, Lincoln, NE