The effects of pretreatments were investigated first. The
corncob substrate was treated with 0.25 or 0.5% sulfuric acid for
10e30 min and then autoclaved at 121 C for 15, 30, 60 min,
respectively. The results are shown in Fig. 1. By treating with
0.25 or 0.5% sulfuric acid for 20 min, approximately 27.1 g/100 g
DS of reducing sugar was produced (Fig. 1a).