蒸汽爆破强度对玉米芯酶水解制备低聚木糖的影响

摘要

The production of xylo-oligosaccharides (XOS) from corncobs was performed by steam explosion pre-treatment combined with selectively enzymatic hydrolysis with endo-xylanase. A new precise quantification method for XOS with a degree of polymerization (DP) of 2–6 was developed using high performance anion-exchange chromatography coupled with pulsed amperometric detector (HPAEC-PAD). The effects of pretreatment intensity and major parameters (reaction temperature and reaction time) on the composition distribution and yield of XOS were investigated in order to find optimal steam explosion pretreatment conditions. The results indicated that the optimal explosion intensity factor, temperature and holding time for steam explosion pretreatment of corncobs were 3.76, 200 ℃ and 390 s, respectively. Under these conditions, the highest yield of XOS was 20.8%. The resulting product was mainly composed of xylotriose, xylotetraose and xylobiose with a relative content of 43.5%, 21.3%and 18.6%, respectively.%以玉米芯为底物，采用蒸汽爆破预处理与内切木聚糖酶定向酶水解相结合制取低聚木糖。基于高效阴离子交换色谱法对聚合度为2～6的低聚木糖组分的准确定量分析，研究蒸汽爆破预处理反应强度系数及其主要参数(反应温度和维压时间)对玉米芯定向酶水解制取低聚木糖的组成分布及产品得率的影响规律，确立最佳蒸汽爆破预处理条件。蒸汽爆破-定向酶解效果综合评价的结果表明，玉米芯最佳的蒸汽爆破预处理条件是反应强度系数3.76、反应温度200℃、维压时间390s。此时低聚木糖得率可达到最高值20.8%，且主要组分以木三糖、木四糖和木二糖为主，含量分别占总得率的43.5%、21.3%和18.6%。