Food emulsions studied by DWS: recent advances

The understanding and manipulation of bulk properties of emulsion systems are of utmost importance in the food industry. Shelf life, mouth-feel and flow properties, to name a few, are to great extent determined by interactions present between the system's constituents. In recent years, great strides have been made in our understanding of colloidal interactions in food emulsions. Traditional experimental techniques such as light scattering, rheology, microscopy and turbidity have been crucial in determining the forces at play in complex food structures. Recently, a new light scattering technique called diffusing wave spectroscopy or DWS, has been increasingly employed in the study of highly turbid food media. Its main advantage is the ability to extract structural and dynamic information between food components in a non-invasive way. DWS has been successfully applied to the study of interactions of dairy proteins as well as the kinetics of aggregation in gelling systems under different destabilizing conditions. However, its application to emulsion systems so far has been relatively limited despite the significant potential in the field. In this document, we will review the DWS work which has been done to date on food emulsions. We will comment on important research headways that were possible with the advent of such a technique. Lastly, we will discuss its capabilities and limitations but most importantly, the huge potential of diffusing wave spectroscopy and its future applications to food.