The structural changes of the bagasse hemicelluloses during the cooking process involving active oxygen and solid alkali

This work describes the structural changes of bagasse hemicelluloses during the cooking process involving active oxygen (O2 and H2O2) and solid alkali (MgO). The hemicelluloses obtained from the bagasse raw material, pulp, and yellow liquor were analyzed by high-performance anion-exchange chromatography (HPAEC), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), and 1H–13C 2D hetero-nuclear single quantum coherence spectroscopy (HSQC). The results revealed that the structure of the bagasse hemicelluloses was l-arabino-(4-O-methylglucurono)-d-xylan. Some sugar units in hemicelluloses were oxidized under the cooking conditions. Additionally, the backbones and the ester linkages of hemicelluloses were heavily cleaved during the cooking process.

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► The backbone of the hemicelluloses was significantly destroyed.
► The side chain was cleaved from the backbone.
► The carbohydrates were oxidized by the active oxygen under the cooking conditions.
► The ester bonds in hemicelluloses were also damaged during the cooking process.