The publicly available NREL suite of laboratory analytical procedures (LAPs) provides researchers with the analytical tools to determine the composition of woody and herbaceous feedstocks. Feedstock characterization includes several steps: sample preparation, starch determination, moisture analysis, ashing, extraction, and hydrolysis. These steps provide information on specific compounds and classes of compounds such as ash, protein, moisture, extractives, sucrose, starch, glucan, xylan, galactan, arabinan, acetate and lignin. Here, we describe the use of these procedures to characterize sorghum [Sorghum bicolor (L.) Moench] with specific consideration of four main sorghum types: grain, forage, sweet, and biomass, which can vary significantly in composition. Special attention is paid to the extraction and the differentiation of glucose from starch and glucan from cellulose in the hybrids with significant amounts of nonstructural carbohydrates.
Keywords: Cellulose; Characterization; Glucan; Hemicellulose; LAPs; Lignin; Lignocellulose; Nonstructural carbohydrates; Sorghum; Starch; Structural carbohydrates; Xylan.