Improvements in the Extractive and Carbohydrate Analysis of Sugarcane Bagasse

Generic procedures for the determination of extractives and carbohydrates (glucose, xylose, galactose, arabinose, mannose) were improved specifically for sugarcane bagasse. The extraction time was optimized using a specific design of experiments. The optimal condition for sugarcane biomass with up to 20% extractives was 11.5 h of extraction in water, followed by 9 h in ethanol. For the carbohydrate analysis, a separation method using liquid chromatography was improved and optimized to reduce the retention time of furanic compounds. The reduction obtained was approximately 30%. The optimal condition was the isocratic elution of the mobile phase with an aqueous solution containing 15% acetonitrile. The percentages of glycans, xylans, and arabinans in the extractive-free biomass was 33%, 22%, and 6.5%, respectively. The galactans and mannans were not detected. Acetyl groups and uronic acids were not determined.