Production of food-grade multiple emulsions with high encapsulation yield using oscillating membrane emulsification

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2014-09, Vol.458, p.78-84
• Main Authors: Vladisavljević, Goran T., Wang, Bing, Dragosavac, Marijana M., Holdich, Richard G.
• Format: Article
• Language: English
• Subjects: Membrane emulsification; Microencapsulation; Multiple emulsion; Oscillating membrane; Sustained release
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2014.05.011

•W/O/W emulsions were produced using 10-μm nickel membrane oscillating at 10–80Hz.•The size of outer droplets of 50–210μm was controlled by the amplitude and frequency.•Only 3–5% of the inner droplets were released during membrane emulsification.•The amount of Cu(II) released from inner droplets was studied over 7 days using AAS.•The release rate followed non-zero-order kinetics with a release exponent of 0.3–0.5. Food-grade water-in-oil-in-water (W/O/W) multiple emulsions with a volume median diameter of outer droplets of 50–210μm were produced by injecting a water-in-oil (W/O) emulsion at the flux of 30Lm−2h−1 through a 10-μm pore electroplated nickel membrane oscillating at 10–90Hz frequency and 0.1–5mm amplitude in 2wt% aqueous Tween® 20 (polyoxyethylene sorbitan monolaurate) solution. The oil phase in the primary W/O emulsion was 5wt% PGPR (polyglycerol polyricinoleate) dissolved in sunflower oil and the content of water phase in the W/O emulsion was 30vol%. The size of outer droplets was precisely controlled by the amplitude and frequency of membrane oscillation. Only 3–5% of the inner droplets with a mean diameter of 0.54μm were released into the outer aqueous phase during membrane emulsification. A sustained release of 200ppm copper (II) loaded in the inner aqueous phase was investigated over 7 days. 95% of Cu(II) initially present in the inner water phase was released in the first 2 days from 56-μm diameter multiple emulsion droplets and less than 15% of Cu(II) was released over the same interval from 122μm droplets. The release rate of Cu(II) decreased with increasing the size of outer droplets and followed non-zero-order kinetics with a release exponent of 0.3–0.5. The prepared multiple emulsions can be used for controlled release of hydrophilic actives in the pharmaceutical, food, and cosmetic industry.