Spontaneous droplet formation techniques for monodisperse emulsions preparation – Perspectives for food applications

Spontaneous droplet formation through Laplace pressure differences is a simple method for making monodisperse emulsions and is claimed to be suited for shear and temperature sensitive products, and those requiring high monodispersity. Techniques belonging to this category include (grooved) microchannel emulsification, straight-through microchannel emulsification, and EDGE (Edge-based Droplet GEneration). In this paper, an overview is given of the process, and design parameters that play a role in microchannel emulsification including their effect on droplet size and distribution. Besides, various products made by microchannel emulsification are discussed. Industrial microchannel emulsification is still not possible due to the low production rates. The new EDGE mechanism seems an interesting development, since it promises larger throughputs per droplet formation unit, better scalability, and shows robust operation with practical, food-grade components. However, for spontaneous emulsification techniques to be used on large scale, improvements in construction materials (including surface modification) are expected to be of essence.