Experimental values for (A) XOS and xylose, (B) arabinose, and galactose obtained during the hydrothermal pretreatment at 110°C to 230°C. The yields of XOS and xylose are expressed as the percentage of the xylan in raw materials. The concentrations of arabinose and galactose are expressed as the concentration in the liquor phase. The error bars are standard deviations from experiments performed in duplicate. XOS, xylo-oligosaccharides.