Surface-engineered magnetic shellac microcapsules as recyclable Pickering interfacial biocatalysts for enzymatic...

Enzymatic synthesis of partial acylglycerols from glycerol and free fatty acids is often limited by poor interfacial mass transfer and low product selectivity. Herein, surface-engineered lipase-loaded magnetic microcapsules were fabricated using natural shellac as recyclable Pickering interfacial biocatalysts. Fe₃O₄ nanoparticles imparted magnetic responsiveness, while the hydrophobic/hydrophilic fumed silica ratio tuned surface wettability and interfacial behavior. Results show that optimal surface wettability yielded uniform Pickering emulsion droplets. The optimized sample M5 exhibited 3.26-fold higher apparent activity than Novozym 435. In glycerol-fatty acid esterification, M5 achieved comparable fatty acid conversion to Novozym 435 while significantly suppressing triacylglycerol formation and enhancing partial acylglycerol selectivity, reaching 86.09% total yield. The catalyst retained high activity after six magnetic recycling cycles. This study establishes a wettability-controllable Pickering biocatalysis platform, offering a promising green strategy for selective enzymatic production of functional lipids rich in partial acylglycerols for food and nutraceutical applications.