微波辅助酸处理桉木预水解液纯化制备低聚木糖

Improvement of Xylo-oligosaccharides Content of Eucalyptus Pre-hydrolysis Liquor with Microwave-assisted Acid Treatment

关键词:  桉木  预水解液  低聚木糖  微波  酸水解

Key Words:Eucalyptus  pre-hydrolysis liquid  xylo-oligosaccharides  microwave  acid treatment

摘要:为利用桉木预水解液制备低聚木糖，对经过Ca(OH)₂和活性炭处理的二级处理预水解液进行微波辅助酸处理，探讨了处理过程中酸类型、酸用量、处理温度和处理时间对预水解液中木糖及聚合度为2～4低聚木糖(低聚木糖_DP2～4)含量的影响，并对处理后预水解液中的低聚木糖进行了分析与表征。结果表明，微波辅助酸处理二级处理预水解液较优工艺条件为：硫酸用量1.4%、处理温度120℃、处理时间 20 min，在此条件下，经过微波辅助酸处理所制备的三级处理预水解液中低聚木糖_DP2～4含量为9.25 g/L，与未经微波辅助酸处理二级处理预水解液相比，其低聚木糖_DP2～4含量提高了38.1%，预水解液中低聚木糖_DP2～4组分得到了进一步纯化。傅里叶变换红外光谱(FT-IR)和热重分析(TGA)结果表明，微波辅助酸处理桉木预水解液纯化制备的低聚木糖含有部分阿拉伯糖及糖醛酸侧链，且该低聚木糖具有较高的热稳定性。

Abstract:In this work，microwave-assisted acid treatment was used to prepare xylo-oligosaccharides(XOS) from the secondary Eucalyptus pre-hydrolysis liquid(PHL) which had been treated by Ca(OH)² and activated carbon successively. The effects of the kinds of acid， acid dosage， treatment temperature and treatment time on xylose and XOS _DP2～4 contents were investigated and the prepared XOS _DP2～4 were characterized. The results showed that the optimal treatment conditions were sulfuric dosage of 1.4%(based on the weight of secondary Eucalyptus PHL)， 120℃ and 20 min， the content of XOS _DP2～4 of the third PHL was 9.25 g/L， increased by 38.1% compared to the secondary PHL without microwave-assisted acid treatment.Analyses of Fourier Transform infrared spectroscopy(FT-IR) and Thermo gravimetric(TGA) showed that XOS from the microwave-assisted sulfuric acid treatment process contained part of side-chains of arabinose and uronic acid，and showed a high thermal stability．