Fabrication of double emulsion gel using monoacylglycerol and whey protein concentrate: The effects of primary emulsion gel fraction and particle size

Abstract

The fabrication of novel double emulgels (DEGs; O/W/O) was examined upon gelling all three phases as oleogel-in-hydrogel-in-oleogel using monoacylglycerol (MAG) and whey protein concentrate (WPC) as gelling agents. Various water proportions from 6.8% to 27.2% (w/w) were incorporated using High-intensity ultrasound (HIU). The HIU effectively stabilised the DEGs for >20 days owing to reducing the particle size of the inner oil phase (from 56.1 μm to 6.5 μm) and causing WPC gelling, immobilising the water phase. The increase in water fraction altered the particle size, whilst the DEG30 sample with 20.4% (w/w) water content reinforced the hardness value (0.48 N) and gel strength. The DEG30 was further treated with various levels of HIU to obtain different particle sizes (104 μm, 67 μm, 88 μm, and 49 μm). The reduction in particle size impacted the final DEGs' rheological behaviour, texture, and Tgel-sol transition temperatures.