Sequential <scp>NaDES</scp> delignification of agave agro‐industrial waste fibers for high purity cellulose fibers and enhanced enzymatic saccharification

Abstract Conventional delignification methods for further enzymatic saccharification and fermentable sugar production usually involve the implementation of alkaline and acid solvents with high negative environmental impact. Natural deep eutectic solvents (NaDES) have emerged as environmentally friendly solvents with the capacity to improve the accessibility of lignocellulosic compounds for diverse processes in the second‐generation biorefinery context, including enzymatic saccharification processes. Therefore, this work aimed to evaluate two sequential methods for lignocellulosic fiber from Agave durangensis leaf waste delignification to enhance glucose production through enzymatic saccharification. Fibers were subjected to ultrasonic and hydrothermal processing, followed by NaDES delignification (NUS and NHT sequential methods, respectively) using a choline chloride–lactic acid mixture. Enzymatic saccharification effectiveness was assessed through glucose yield and saccharification efficiency. The NHT sequential method yielded the highest cellulose purity (88.2 ± 0.97 wt%) owing to an effective hemicellulose solubilization and lignin relocation. In comparison, the NUS sequential process led to the obtention of fibers with a cellulose content of 63.26 ± 0.66 wt%. Enzymatic hydrolysis of pretreated samples demonstrated an improvement in glucose production, where the NHT sample exhibited the higher potential on fermentable sugar production (88.96 ± 1.47 g L −1 of produced glucose), confirming enhanced cellulose digestibility with a saccharification yield of 92.23 ± 1.56%. Integrating ultrasonic and hydrothermal pretreatments with NaDES delignification increased cellulose accessibility through combination of physical and chemical processes. Optimization of processing parameters is recommended for scalability and industrial feasibility.