Effects of cellulose and lignin on xylooligosaccharides production from xylan: The superiority of acetic acid/sodium acetate hydrolysis

Xylooligosaccharides (XOS) are high-value products derived from xylan in lignocellulose and have a variety of prebiotic applications. The intertwining of xylan, cellulose, and lignin in lignocelluloses may affect XOS pro-duction. In order to investigate those impacts, the comparative analysis of XOS production was conducted using corncob, poplar and xylan as substrates through the hydrolysis using acetic acid/sodium acetate (AC/SA), acetic acid (AC), and pure water. The results revealed that the hydrolysis of different feedstocks using AC/SA generated the highest XOS yield and the least by-products compared to AC hydrolysis and hydrothermal (HT) treatment. The presence of cellulose led to the reductions of XOS production from xylan by AC/SA hydrolysis, AC hydro-lysis, and HT treatment by 6.6%, 6.3%, and 4.3%, respectively. The presence of cellulose and lignin largely decreased XOS yields by 22.2%, 22.0%, and 88.5%, respectively. Obviously, the cellulose slightly inhibited xylan hydrolysis, while lignin had a strong negative effect on xylan hydrolysis. Besides, the adverse effect of lignin on xylan hydrolysis was the greatest in HT treatment. Despite the presence of cellulose and lignin, AC/SA hydrolysis exhibited the superior ability in XOS production and reduced the formation of by-products compared to AC hydrolysis and HT treatment.