Effects of steam explosion pretreatment on the extraction of xylooligosaccharide from rice husk

Rice husk, which contains hemicellulose, can be used as a renewable resource to produce xylooligosaccharide (XOS). However, it is difficult to destroy the lignin structure of rice husk. Steam explosion (SE) is an effective method in destroying the lignin structure to enhance the release of hemicellulose and cellulose. In this study, SE pretreatment was used at different high pressures. The results showed that the lignin structure of rice husk could be collapsed by SE pretreatment, and the chemical structures of rice husk were evaluated by Fourier transform infrared spectroscopy (FTIR). The SE pretreatment resulted in the significant increase of XOS content and antioxidant activities. In summary, SE pretreatment under 2.5 MPa was chosen as a good option for the production of XOS from rice husk.