Abstract
Production of L-arabinose and xylose from arabinoxylan in corn hull and bagasse was investigated using dilute hydrochloric acid treatment at 125 or 130°C. In the corn hull arabinoxylan, which has a high L-arabinose content (Ara/Xyl=0.590), L-arabinose was more preferentially released than xylose as a result of less than 5 min treatment with 0.2 M HCl at 125°C. The yield from arabinoxylan was 73% after 5 min treatment, but high L-arabinose ratio of 60% was obtained in the released xylose and L-arabinose mixture. After 20 min treatment, the amounts of L-arabinose and xylose were increased to 162 and 290 mg/g corn hull, and their yields from the corn hull arabinoxylan were 89 and 99%, respectively. Furthermore, during enzymatic hydrolysis using cellulase, glucose was significantly released from the HCl-treated corn hull. On the other hand, in the bagasse arabinoxylan which has a low L-arabinose content (Ara/Xyl=0.073), the L-arabinose yield from arabinoxylan was 99%; however, the xylose yield was smaller (63%) and glucose release was not enhanced with enzymatic hydrolysis because of higher lignin content.
