Alkaline extraction of hemicellulose from lignocellulosic materials is an efficient separation method but also extracts polysaccharides with high proportions of lignin. In this study, aromatic-selective adsorption resin was used to the remove lignin in the purification of alkaline-extracted hemicellulose from sugarcane bagasse. The content of lignin in the alkaline extracted hemicellulose decreased and the removal rate reached 89.2% at 1/10 wt ratio of lignin to resin. Resin treatment led to a slight loss of hemicellulose but had a minute effect on its molecular weight and structure. The 2D heteronuclear single quantum coherence (HSQC) NMR analysis of adsorbates suggested that the decrease in carbohydrate contents in the extract resulted from the removal of the lignin-carbohydrate complexes (LCCs) during the resin treatment. It was concluded that the resin treatment had a minute effect on the properties of hemicellulose and could significantly improve its separation and purification.
Keywords: Alkaline extraction; Aromatic-selective adsorption resin; Hemicellulose; Lignin-carbohydrate complexes; Sugarcane bagasse.
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