Encapsulation of resveratrol via spray-drying of oil-in-water emulsions produced by ultrasound or membrane emulsification

Resveratrol emulsions do not have long shelf life hence drying to obtain powder can result in the resveratrol protection, shelf life extension and can unlock versatile applications in food, pharmaceuticals, and cosmetics. In this work resveratrol was emulsified using drop-by-drop ("batch" and "continuous" membrane) and classic (ultrasound) emulsification methods followed by the emulsion spray drying to obtain resveratrol loaded microparticles. Influence of the emulsification techniques on the microparticles properties, resveratrol encapsulation efficiency and retention were evaluated and the energy density required by each emulsification process was estimated. 10 and 15 μm pore membranes produced droplets between 154 and 42 μm, while with the ultrasound droplets of 0.16 μm were produced. The microparticles obtained by spray-drying of the emulsions produced by ultrasound and "batch membrane system" had the highest encapsulation (∼97%) efficiency and similar resveratrol retention (∼89%). This confirms that membrane systems (even producing larger droplet size compared to ultrasound emulsions) could achieve high encapsulation efficiency and resveratrol retention. Since no cooling is needed during membrane emulsification due to the low energy input, membrane systems with their ability to be scaled up, should be considered in food and pharma as an alternative to classical emulsification systems especially when shear and heat sensitive compounds are emulsified and encapsulated.