Journal of Food Engineering, Vol.263, 326-336, 2019
Low-energy high-throughput emulsification with nickel micro-sieves for essential oils encapsulation
Lemon oil is widely used in food manufacturing, however its tendency to oxidize and its lipophilic character requires its encapsulation, either in emulsions or in microcapsules. Conventional emulsification technologies are highly energy intensive, damaging shear and heat sensitive products. This work assesses a high-throughput low energy premix emulsification system based on nickel micro-sieves to produce food grade lemon oil-water emulsions. Successful encapsulation is achieved when both the lemon oil fraction is about 5% and the ratio between the size of the coarse emulsion and the hydraulic diameter of the micro-sieves (d(ratio)) is 1 or lower. These conditions result in high fluxes (400-800 m(3) m(-2) h(-1) at 450 kPa) and emulsions of about 0.5 mu m after 5 emulsification cycles. Droplet break-up mechanisms differ in the first emulsification cycle depending on the pore size and geometry of the micro-sieve.