Optimized use of hemicellulose within a biorefinery for processing high value-added xylooligosaccharides

Wheat straw was used to produce xylooligosaccharides (XOS) for its prebiotic effect. Steam explosion (SE) pre-treatment has been used to separate the main components of lignocellulosic material: cellulose, hemicellulose and lignin. SE conditions used gave a cellulose recovery as solid fraction (91%) and a xylan recovered in the liquid fraction (LF) (36%). Previously to XOS production by enzymatic hydrolysis of xylan, the LF was subjected to a cleaning step with ion exchange resin to remove soluble inhibitors. The commercial enzyme endo-1,4-β-xylanase was used individually and in combination with β-glucosidase to produce compounds with a low degree of polymerization (DP2-DP6). The process achieved a conversion rate of 91% to XOS with 5 h of hydrolysis supplementation, whatever generated 8.9 g of XOS per 100 g of raw material.