| Abstract:In this paper, xylanase treatment was used to prepare xylo-oligosaccharides (XOS) from the secondary eucalyptus pre-hydrolysis liquor (PHL) which had been treated with Ca(OH)2 and activated carbon successively. The effects of xylanase dosage, treatment time, treatment temperature and pH value on XOSDP2~4 contents were investigated and the prepared XOS were characterized. The results showed that the optimal treatment conditions were xylanase dosage of 2 U/g (based on the weight of secondary eucalyptus PHL), treatment time of 3 h, treatment temperature of 55 ℃ and pH value of 5.5, The content of XOSDP2~4 of the third PHL was 12.22 g/L, increased by 67.2% compared to the secondary PHL, and the content of XOSDP2~4 of third PHL accounted for 56.1% of the total xylose in the eucalyptus PHL. Analysis of Fourier Transform infrared spectroscopy (FT-IR) and Thermo gravimetric (TGA) showed that XOS obtained with xylanase treatment process contained part of side-chains of uronic acid and showed a high thermal stability. |
