Effects of pretreatment methods on hydrolysis of cassava residue

To increase the fermentation efficiency of cassava residue,13 pretreatment methods were used to hydrolyze cassava residue.By transferring organic matters into the liquid phase from the solid phase,the concentration of monosaccharides,oligosaccharides and total sugar in the hydrolysate from different pretreatment methods were investigated.The results showed that all the treatment methods were effective,with the weak acid of 0.5% HNO3 at high temperature being the best,yielding a concentration of glucose and xylose in the hydrolysate of 22 606 mg/L and 1 509 mg/L,oligosaccharides at 7 856 mg/L,and total sugar at 33 682 mg/L.The effect of hydrolysis for cassava residue with NaOH and hot water pressure were not obvious.In enzymatic hydrolysis,cellulase with the addition of emicellulase was more preferable than only single enzymes,and cellulase with the addition of weak acid was more preferable than hydrolysis with enzymes directly,cellulase and emicellulase with 1% H2SO4 gave the best results with glucose and xylose in the hydrolysate at 19 757 mg/L and 1 504 mg/L respectively,oligosaccharides at 19 853 mg/L,and total sugar at 43 196 mg/L.