Delignification of switchgrass for xylo-oligosaccharides production using sorbic acid hydrolysis

Organic acid as a class of hydrolysis catalysts shows great potential in the production of xylo-oligosaccharides (XOS) from lignocelluloses. However, sorbic acid (SA) hydrolysis for XOS production from lignocellulose has not been reported and it was still unclear how lignin removal affected XOS production. Herein, two factors affecting the XOS production from switchgrass by SA hydrolysis were explored: hydrolysis severity factor (Log R0) and lignin removal. Benefiting from the lignin removal (58.4%) in switchgrass, a desired XOS yield of 50.8% with low by-products was obtained from delignified switchgrass by 3% SA hydrolysis at Log R0 = 3.84. Under these conditions, 92.1% of glucose was obtained by cellulase hydrolysis with Tween 80 addition. From a mass balance perspective, 10.3 g of XOS and 23.7 g of glucose could be produced from 100 g switchgrass. This work proposed a novel strategy for XOS and monosaccharides production from delignified switchgrass.