Improvement of xylo-oligosaccharides release from Camellia oleifera shells by 3MeV electron-beam irradiation combined with hydrothermal treatment

Xylo-oligosaccharides (XOS) have demonstrated extensive benefits for health promotion and are widely used in food, medicine, and chemical industries. While lignocellulosic biomass is a common source, the potential of Camellia oleifera shells (COS) as a raw material for XOS production remains underexplored. The study explored the effects of irradiation doses, hydrothermal temperatures, reaction times, and solid-liquid ratios on the preparation of XOS from COS via a novel method involving electron-beam irradiation and hydrothermal treatment. Optimal conditions (200 kGy, 180 °C, 30 min, 1:10 ratio of solid loading) resulted in the XOS yield of 70.35 %, with X 2–4 (XOS of DP 2–4) comprising 23.37 % and a xylose/XOS ratio of 0.21. Meanwhile, minimal by-products were detected, including 0.83 g/L acetic acid and less than 0.50 g/L of formic acid, furfural, and 5-hydroxymethylfurfural (5-HMF). Furthermore, xylanase digestion optimization yielded an X 2–4 concentration of 11.78 g/L and a X 2–4 /XOS ratio of 84.93 %. This approach offers a promising and eco-friendly route for XOS production from COS, with implications for valorizing agricultural waste and advancing sustainable biorefinery practices. • XOS production from COS was optimized by irradiation-hydrothermal treatment. • High XOS yield of 70.35 % and concentration of 13.87 g/L was achieved. • X 2–4 content was 11.78 g/L and X 2–4 /XOS ratio was 84.93 % by xylanase digestion. • The method enhances the value of COS as an agricultural byproduct.