Shellac-chitosan microgel-immobilized lipase for sustainable synthesis of sucrose laurate via pickering interfacial catalysis

Sucrose fatty acid esters are increasingly valued as multifunctional surfactants, nutraceuticals, and bacteriostats due to their emulsifying and antimicrobial properties. While enzymatic synthesis provides an eco-friendly route to high-purity esters, challenges remain in optimizing lipase activity, reusability, and mass transfer. This study introduces a novel edible biomaterials-based catalytic system: lipase immobilized within shellac nanoparticle-coated chitosan microgels (SCL) for synthesizing sucrose laurate via Pickering interfacial catalysis (PIC). SCL stabilized oil-in-water (O/W) emulsions, with sucrose and vinyl laurate partitioned into aqueous and oil phases, respectively. Structural characterization (SEM, CLSM, Cryo-SEM) revealed SCL's localization at the O/W interface, with preferential oil-phase immersion and ordered interfacial alignment. Optimized conditions yielded a conversion rate of 55.35 ± 1.88 %, and the immobilized lipase retained >80 % activity over four cycles. Purified via solvent extraction and chromatography, the product was confirmed as 6-sucrose monolaurate (through FT-IR, NMR, XRD, and TG-DSC). Comparative analysis demonstrated its higher air/water interfacial stabilization versus commercial sucrose monoesters, evidenced by lower critical micelle concentration ( cmc ), enhanced emulsifying/foaming capacity, and improved pH/thermal stability. Collectively, this SCL-based PIC system achieved sustainable synthesis of 6-sucrose monolaurate with exceptional enzyme recyclability, overcoming limitations in lipase stability and mass transfer, and produced a surfactant with superior properties.