Deacetylation degree modulates interfacial interactions and delivery performance of konjac glucomannan-soy protein microcapsules for encapsulating Zanthoxylum bungeanum essential oil.

Although Zanthoxylum bungeanum essential oil is rich in bioactive compounds, its broader application is restricted by inherent volatility and oxidative instability. This study aimed to investigate how the degree of deacetylation (DD) modulates the interfacial interactions between deacetylated konjac glucomannan and soy protein isolate composite wall materials. The microcapsules exhibited the optimal performance at a DD of 27.44%, with the highest encapsulation efficiency of 79.75% ± 1.70%, the smallest emulsion droplet size of 0.99 ± 0.01 μm, and the highest storage modulus value. Structural characterization and molecular docking (binding energy of -7.0 for the optimal formation) indicated that deacetylation to this degree reduced steric hindrance, thus promoting the formation of a physical network driven by hydrogen bonding and hydrophobic interactions. The optimized matrix significantly improved sanshool stability over a 33-day storage period and enabled targeted intestinal release, with a release rate 42% higher than that of single-protein microcapsules. This study establishes a structural basis for designing polysaccharide-protein composite wall materials to encapsulate and deliver volatile bioactive oils.