Investigation into the potential ability of Pickering emulsions (food-grade particles) to enhance the oxidative stability of oil-in-water emulsions

Lipid oxidation was monitored by measuring the concentration of primary lipid oxidation product, using the peroxide value method. Increasing the Microcrystalline cellulose (MCC) concentration from 0.5% to 2.5% results in a decrease in the hydroperoxide formation due to their ability to scavenge free radicals through their negative charge and build a thick interface around droplets. [Display omitted] ► Oil-in-water emulsions stabilised by food grade particles. ► Physical and oxidative stability of samples were monitored over extended time. ► Increasing the particle concentration was found to decrease droplet size. ► MCC particles significantly reduced the lipid oxidation rate. In this study the potential ability of food-grade particles (at the droplet interface) to enhance the oxidative stability was investigated. Sunflower oil-in-water emulsions (20%), stabilised solely by food-grade particles (Microcrystalline cellulose (MCC) and modified starch (MS)), were produced under different processing conditions and their physicochemical properties were studied over time. Data on droplet size, surface charge, creaming index and oxidative stability were obtained. Increasing the food-grade particle concentration from 0.1% to 2.5% was found to decrease droplet size, enhance the physical stability of emulsions and reduce the lipid oxidation rate due to the formation of a thicker interfacial layer around the oil droplets. It was further shown that, MCC particles were able to reduce the lipid oxidation rate more effectively than MS particles. This was attributed to their ability to scavenge free radicals, through their negative charge, and form thicker interfacial layers around oil droplets due to the particles size differences. The present study demonstrates that the manipulation of emulsions’ interfacial microstructure, based on the formation of a thick interface around the oil droplets by food-grade particles (Pickering emulsions), is an effective approach to slow down lipid oxidation.