Effects of different pretreatments on pumpkin (Cucurbita pepo) lignocellulose degradation

The efficiency of enzymatic hydrolysis is reduced by the naturally recalcitrant complex polymers comprising lignocellulose. Increasing enzymatic conversion, which the complex macromolecules converted into simpler molecules, is still had to be overcome. High hydrostatic pressure (HHP), an emerging technology, is expected to ameliorate the situation. The effects of enzymatic hydrolysis after HHP pretreatment on pumpkin lignocellulose were studied and compared with hydrothermal and alkaline pretreatment. Further investigation was performed to evaluate the effect of enzymatic hydrolysis of pumpkin combined with HHP treatment. The samples underwent HHP treatment simultaneously exhibited overall better performance in enzymatic hydrolysis than the untreated. The highest glucose yield of 91.2% and xylose yield of 84.2% was achieved when 400 MPa HHP with high enzyme loading was applied. HHP exerted positive effects on enzyme-substrate interactions during the enzymatic hydrolysis of lignocellulose, which implied that HHP technology combined with enzymatic hydrolysis could be used to pretreat pumpkin pomace.