Selective production of xylo-oligosaccharides and xylose for further application and co-production of fermentable sugars from corncob via controlled ammonium persulfate-assisted hydrothermal pretreatment.

Ammonium persulfate (APS)-assisted hydrothermal pretreatment (HP) is an emerging method for xylan depolymerization, yet its potential for integrated valorization of all biomass fractions remains underexplored. This study aimed to selectively produce xylo-oligosaccharides (XOS) and xylose from corncob via controlled APS-HP, evaluate XOS bioactivity, and ferment xylose hydrolysate to xylonic acid without detoxification, while assessing enzymatic digestibility of solid residues. Under 0.5 % APS at 150 °C for 90 min, an optimal XOS yield reached 40.90 % (based on xylan in corncob), whereas 1 % APS gave a maximal xylose yield of 56.34 %. The XOS hydrolysate at 50 mg/L improved Chinese cabbage (Brassica rapa L. var. pekinensis) seed germination, plant height, root elongation, and fresh biomass, revealing its agricultural bioactivity. Notably, the xylose hydrolysate without detoxification was converted to xylonic acid with a yield of 90.32 % within 24 h, and even a 2.15-fold concentrated hydrolysate achieved 90.36 %, demonstrating process robustness. Solid residues from XOS and xylose production exhibited excellent enzymatic digestibility, with glucose yields of 96.89 % and 99.03 %, respectively, at 20 FPU/g glucan. Preliminary techno-economic analysis and qualitative life cycle assessment are used to assess economic theoretical basis for practical industrial production. Collectively, this study presents a novel integrated biorefinery strategy enabling sequential production of bioactive XOS, fermentable xylose, and highly digestible solid residues from corncob via APS-HP, offering a promising route for comprehensive lignocellulosic carbohydrates utilization without requiring a separate detoxification step.