Microwave-assisted acid hydrolysis to produce xylooligosaccharides from sugarcane bagasse hemicelluloses

Hemicelluloses from sugarcane bagasse were subjected to microwave-assisted acid hydrolysis at mild temperature to produce xylooligosaccharides (XOS). The hydrolysis was performed with dilute H2SO4 at 90 °C and the influence of acid concentration (0.1-0.3 M) and reaction time (20-40 min) on the XOS production was ascertained with response surface methodology based on central composite design. The fitted models of XOS and xylose yields were in good agreement with the experimental results. Compared to hydrolysis time, acid concentration was a more significant coefficient in the production of XOS. A well-defined degree of polymerisation of XOS and the monomer in the hydrolysates were quantified. No sugar-degraded byproduct was detected. The maximum XOS yield of 290.2 mg g−1 was achieved by hydrolysis with 0.24 M H2SO4 for 31 min. The results indicated that the yields of xylose and the byproducts can be controlled by the acid concentration and reaction time in microwave-assisted acid hydrolysis.