RSM-Modeling and Optimization of High Titer Functional Xylo-oligosaccharides Production by Edible Gluconic Acid Catalysis.

Xylo-oligosaccharides have great value in food, feed fields. Previous studies have shown that organic acids catalyze the hydrolysis of xylan-rich sources for the production of xylo-oligosaccharides. In this study, gluconic acid of aldonic acid generated xylo-oligosaccharides via hydrolysis of xylan from corncob. In order to maximize efficiency of xylo-oligosaccharides production, the optimum conditions was ascertained by Box-Behnken design-based response surface methodology. The developed process resulted in a maximum xylo-oligosaccharides yield of 57.73% using 4.6% gluconic acid at 167 °C for 28 min, which was similar to the predicted value and fitted models of xylo-oligosaccharides production. The results showed that the reaction temperature was crucial to xylo-oligosaccharides production, and by-product yields (xylose and furfural) could be effectively controlled by both reaction temperature and time. In addition, 44.87 g/L XOS was achieved by decreasing the solid-liquid ratio. Overall, the described process may be a preferred option for future high concentration xylo-oligosaccharides production.