Efficient extraction of melon (Cucumis melo L.) seed husk cellulose and saccharification enhancement by E-beam pretreatment combined with alkaline deep eutectic solvents

Melon seed husk is an agricultural waste rich in lignocellulose, and its high-value utilization is of great significance for sustainable development. However, the recalcitrant structure of lignocellulose poses a major bottleneck to achieving efficient bioconversion. This study aims to elucidate the mechanism of efficient deconstruction of melon seed husk cellulose via synergistic pretreatment with electron beam irradiation (EBI) and a deep eutectic solvent (DES), and to develop a green biorefinery process. We applied synergistic pretreatment of melon seed husk using varying doses of EBI and choline chloride/urea DES. The structural evolution of the pretreated material was analyzed at multiple scales, and its saccharification efficiency was evaluated via enzymatic hydrolysis. The results revealed that EBI dose-dependently disrupted the hydrogen-bonding network and the crystalline structure of cellulose, reducing its crystallinity by 0.95 %–11.54 % and forming a porous network. The synergistic pretreatment exhibited a significant dose-threshold effect. At the optimized dose of 150 kGy, the cellulose-binding rate was significantly enhanced, resulting in a saccharification yield of 48.29 %. This study provides a theoretical foundation and a feasible strategy for the industrialization of green biomass refining. • The dose window for EBI-assisted DES extraction of cellulose was clearly quantified. • The hydrogen bond competition-lattice swelling pathway of EBI-DES treatment was confirmed. • Improved the yield of cellulose prepared by DES and facilitated the removal of lignin. • Enhanced saccharification yield of cellulose extracted by DES and cellulose conversion.