Magnetically actuated β-glucosidase immobilized on oak chips for enhanced wine aroma release.

β-Glucosidase (BGL) plays a key role in wine aroma enhancement by hydrolyzing glycosidic precursors; however, its application is limited by instability under harsh winemaking conditions. To address this, we developed an integrated biocatalytic system by immobilizing an acid-tolerant BGL onto functionalized magnetic oak chips (NFOak) via oriented Ni2+-histidine coordination. Comprehensive characterization confirmed the fabrication of a porous, magnetic cellulose scaffold. The immobilized BGL exhibited significantly enhanced stability against winemaking stresses (low pH, high ethanol) compared to the free enzyme. Furthermore, magnetic actuation of the biocomposite improved its hydrolytic performance, likely attributed to enhanced mass transfer. When applied to Chardonnay and Marselan wines, the magnetically actuated system effectively hydrolyzed glycosidic precursors, markedly increasing the concentrations of key volatile compounds-such as linalool and ethyl benzoate associated with fruity and floral aroma profiles. The treatment also induced subtle modulations in wine color and phenolic composition. Safety assessments confirmed no nickel leaching and oenologically acceptable iron levels. This work provides a sustainable and efficient strategy for controllable aroma modulation, combining the oenological benefits of a natural oak carrier with the operational controllability of magnetic actuation.