Alkali-Catalyzed Organosolv Pretreatment of Lignocellulose Enhances Enzymatic Hydrolysis and Results in Highly Antioxidative Lignin
Lei Zhong, Chao Wang, Miaomiao Xu, Xingxiang Ji, Guihua Yang, Jiachuan Chen, Srinivas Janaswamy, Gaojin Lyu
Abstract
Herein, efficient exploitation of biomass with diluted alkali-aided methanol organosolv treatment has been proposed. The ultrahigh glucose yield and high value-added lignin from xylose residue were simultaneously achieved via the mild alkali catalytic organosolv treatment and enzymatic hydrolysis. The NaOH-aided methanol pretreatment resulted in a more efficient delignification of 86.7%, which significantly facilitated the cellulase accessibility toward gaining a high glucose yield of 97.7%. In addition, the recovered lignin is highly pure with small and homogeneous molecular weight and high thermal stability. The total phenolic and antioxidant activities of the lignin were carried out by a Folin–Ciocalteu method and radical DPPH and ABTS assays, respectively. Results revealed that the modified lignin effectively scavenged radicals compared to the commercial antioxidants (butylated hydroxytoluene). Overall, this study provides a mild but a highly promising pretreatment approach for energy production from biomass. The excellent radical scavenging capacity of the obtained lignin further sets the stage for biobased functional materials in the popular biorefinery.