Effect of enzymatically hydrolyzed acylglycerol on the complex coacervation behavior of gelatin-stabilized oil-in-water emulsions

The increasing demand for omega-3 products has driven the need for effective methods to stabilize these unsaturated oils. This paper investigated the effects of enzymatically produced acylglycerols on the complex coacervation behavior of gelatin-stabilized emulsions. Acylglycerols with different lipid profiles were produced via hydrolysis of tuna oil catalyzed by lipozyme TL IM from Thermomyces lanuginosus (TLIM) and lipase MHA "Amano" 10SD from Mucor javanicus (10SD), respectively. Oil-in-water emulsion was prepared using the modified acylglycerols, subsequently, sodium hexametaphosphate was introduced to induce the complex coacervation of emulsions. The complex coacervates were characterized by various factors including surface charge, microstructure, fluorescence properties, and gelatin adsorption kinetics. The optimal pH for complex coacervation formation was found at 4.90, resulting in the lowest absolute value of zeta-potential. Aylglycerols exhibited a better coacervation effect compared to tuna oil, with higher coacervation yields of 64.9–70.0%. Notably, lipase 10SD-modified acylglycerol-based complex coacervates exhibited superior properties in morphology, coacervation yield, and gelatin adsorption rate, highlighting the pivotal role of higher content of monoacylglycerol and diacylglycerol within the acylglycerol in facilitating the complex coacervation. These findings suggest that the utilization of hydrolyzed acylglycerol in complex coacervation could be a promising potential for the application in stabilizing and delivering omega-3 oils. • Abundant diacylglycerol and monoacylglycerol were produced via enzymatic hydrolysis. • Complex coacervation of emulsion was promoted by diacylglycerol and monoacylglycerol. • Lipid profile of modified acylglycerol decided its formed complex coacervate. • Diacylglycerol and monoacylglycerol contributed to the hydrophobic interactions.