Cross-flow microfluidic emulsification from a food perspective

Background: The use of microfluidics is a relatively new route to produce emulsions. Advantages of this method include high energy efficiency, high droplet monodispersity, and potential use for the production of high added-value and fragile products. However, the current productivity is still rather low compared to what would be needed in an industrial setting.Scope and Approach: In this review we discuss the mechanisms of emulsion droplet formation in crossflow microfluidics, and how microfluidic design, shear forces and interfacial tension forces influence droplet formation. These combined insights will be used to discuss the potential of cross-flow microfluidics for the production of food emulsions.Key Findings and Conclusions: In order to make emulsions at large scale, the current devices need to be parallelised even more than shown in the successful examples known from literature. Besides, the behaviour of ingredients used in emulsion formulation need to be tested in greater detail; e.g. the effectof interfacial tension is captured in scaling relations, but dynamic interfacial tension behaviour not. For this also microfluidic analytical tools have been suggested, and the first positive results were obtained. As soon as these two requirements are met, microfluidics become a promising option for the production of (high added-value) emulsion food products