Coproduction of xylooligosaccharides, glucose, and less-condensed lignin from sugarcane bagasse using syringic acid pretreatment.

[Display omitted] • Syringic acid (SA) pretreatment was used to achieve the full utilization of SCB. • 58.7% XOS DP 2–6 was obtained at 180 °C/20 min with 9% SA additive. • Lignin degree of condensation decreased from 0.55 to 0.42 after SA additive. • Glucose yield reached 92.4% at lower enzyme due to the less lignin inhibition. • SA is a catalyst, lignin condensation inhibitor, and antimicrobial. Current strategies for the production of xylooligosaccharides (XOS) from biomass through non–enzymatic catalysis often led to a certain degree of lignin condensation, which severely restrains subsequent enzyme hydrolysis of cellulose. Herein, syringic acid (SA) pretreatment was investigated to coproduce XOS, glucose, and less-condensed lignin from sugarcane bagasse. SA acted as a catalyst and lignin condensation inhibitor during the pretreatment. The highest XOS yield of 58.7% (27.7% xylobiose and 24.7% xylotriose) was obtained at 180 °C − 20 min − 9% SA, and the corresponding xylose/XOS ratio was only 0.42. Compared with the pretreatment at 180 °C − 20 min − 0% SA, the addition of 9% SA increased the glucose yield from 85.7% to 92.4% and decreased the degree of lignin condensation from 0.55 to 0.42. Moreover, 26.7% of SA could be easily recovered. This work presents a pretreatment strategy in which the efficient production of XOS and the suppression of lignin condensation are achieved simultaneously. [ABSTRACT FROM AUTHOR]