Analysis of sorghum wax and carnauba wax by reversed phase liquid chromatography mass spectrometry

Sorghum is a genus of plant in the grass family, which is used for both grain and forage production throughout the world. In the United States, sorghum grain is predominantly used as livestock feed, and in ethanol production. In recent years however, sorghum grain has been investigated for other industrial applications, including gluten free food sources for the US food market, and waxes. The United States is the world's largest producer of grain sorghum, which is grown in the arid regions of the southern Great Plains, Arizona and California. Carnauba wax is used in a variety of products; including cosmetics, industrial polishes, food products, and paper products. The United States has no domestic source of carnauba wax, and imports 100% of its carnauba wax supply. Sorghum wax has demonstrated similar physical properties to carnauba wax, and could potentially be a viable substitute for carnauba wax. In this paper we present the first successful reversed phase HPLC method, via a C30 column, for the analysis and characterization of waxes, without the need for specialized columns or sample derivation. Sorghum wax is composed of a heterogeneous mixture of compounds, dominated by C28 and C30 saturated and unsaturated species, while carnauba is more homogeneous in nature, and composed primarily of C56-C60 saturated wax esters. (C) 2016 Published by Elsevier B.V.