This book will review old and new methods to study emulsion stability and structure. Examples
of emulsion-based foods include ice cream yoghurt and mayonnaise. The physicochemical
properties of emulsions play an important role in food systems as they directly contribute to
the texture sensory and nutritional properties of foods. One of the main properties is
stability which refers to the ability of an emulsion to resist physical changes over time. The
development of an effective strategy to prevent undesirable changes in the properties of a
particular food emulsion depends on the dominant physicochemical mechanism(s) responsible for
the changes. In practice two or more of these mechanisms may operate in concert. It is
therefore important for food scientists to identify the relative importance of each mechanism
the relationship between them and the factors that influence them so that effective means of
controlling the stability and physicochemical properties of emulsions can be established.
Several techniques are used to study the physical behavior and structure of emulsions. Each
technique has its advantages and disadvantages and provides different insights into the
destabilization mechanisms. Among the oldest methods used to study emulsion stability is visual
observation and small deformation rheometry. More recently other techniques such as
ultrasound profiling microscopy droplet size distribution and measurement of surface
concentration to characterize adsorbed protein at the interface have also been employed. Some
of these techniques such as droplet size distribution involve some form of dilution. However
dilution disrupts some structures that play an important role in stability. The ability to
study the stability of food emulsions in their undiluted form may reveal subtle nuances about
their stability. Diffusing wave spectroscopy (DWS) laser scanning confocal microscopy (LSCM)
nuclear magnetic resonance (NMR) and Turbiscan are among the more powerful non-perturbing
techniques used to characterized emulsions.
