Plant Sterol and Policosanol Characterization of Hexane Extracts from Grain Sorghum, Corn and their DDGS

Plant sterols (PS) and policosanols (PC) have been attributed with plasma cholesterol-lowering properties in humans. Hexane extracts from grain sorghum, corn and their distillers dried grain with solubles (DDGS), an important co-product of ethanol production, contain these health promoting compounds, which could be used to develop health promoting dietary products. However, limited information is currently available regarding optimal methods of extraction and their influence on plant sterol or PC levels and compositions. Therefore, the objective of this study was to quantify lipids, particularly PS and PC extracted from grain sorghum and its DDGS using reflux and Soxtec methods. Corn and its DDGS were also extracted to compare lipid yields and PS/PC compositional profiles in these two related cereals. Intact grains were extracted either as whole or ground kernels. Lipid yields from all the corn sources were typically greater than those obtained from grain sorghum. Lipid yields from DDGS were the highest among all the forms of the grains used whereas corn/sorghum DDGS contained the highest levels of PS and PC, respectively. Additional study demonstrated that hydrolysis (acidic and alkaline) of ground sorghum or sorghum DDGS increased the levels of total extractable plant sterols. Overall, the Soxtec method extracted higher amounts of lipids than the reflux method.