Morphology-regulated Pickering emulsions stabilized by soybean residue-derived nanocellulose for tunable-release...

Biomass-based active packaging enables precise and simultaneous control over both interfacial stabilization and the release behavior of volatile bioactive compounds. In this study, fully biomass-based sustained-release films were fabricated via the encapsulation of lemon essential oil (LEO) within Pickering emulsions stabilized by the soybean residue-derived nanocellulose with distinct morphologies. Specifically, the LEO-loaded Pickering emulsions were fabricated using 0.2-0.6 wt% nanocellulose and carboxymethyl chitosan (CMCS) at a 1:5 (w/w) ratio, with a 3:7 (v/v) oil-to-water ratio and a beeswax-to-LEO ratio of 1:1 (v/v). Rigid particle shells were formed by CMCS/nanocellulose complexes through morphology-dependent interfacial packing, thereby generating uniform droplets and substantially enhancing emulsion stability. When incorporated into chitosan (CS), these emulsions reconfigured and reinforced the internal film network, which enabled tunable mechanical, barrier, and release properties. Films incorporated with 2 wt% CMCS/long rod-shaped cellulose nanocrystals (L-CNCs) Pickering emulsion exhibited a more compact microstructure, higher tensile strength (20.38 MPa), lower water vapor permeability (7.30 × 10^-7 g/m·s·Pa), and slower LEO diffusion, which was attributed to strengthened CS-particle interfacial interactions. When applied as edible coatings, the films effectively delayed blueberry senescence by reducing weight loss and preserving firmness and titratable acidity for up to 14 days. Overall, this work provides mechanistic insights into morphology-regulated interfacial assembly and offers a scalable strategy for the development of green packaging films with tunable sustained-release behavior.