Dynamic membranes of tunable pore size for lemon oil encapsulation

Abstract

Encapsulation of lemon oil (LO) is a challenging process due to the heat and shear sensitive nature of its volatile compounds. Using a low-shear high-throughput emulsification technique is a good alternative to conventional energy intensive techniques. In this study, LO emulsions are prepared with a dynamic membrane of tunable pore size (DMTS) system, where the emulsion is passed and refined repetitively through a microporous bed of silica micro-beads supported by a nickel sieve. It was observed that selecting micro-beads size and bed height affected the droplet size distribution and emulsification fluxes, nonetheless emulsions were generally stable for 7 days at two temperatures (25 and 4 °C). More importantly, emulsions with oil fractions up to 40%wt. and narrow size distributed droplets were prepared. A novel structural modification of the DMTS, consisting of two superimposed layers of different micro-beads sizes, reduced the energy input of the emulsification process while obtaining emulsions with similar droplet size distribution.