Controlling product microstructure
Peter Graham, Unilever R&D
Consumers perceive differences in product structure via their visual appearance, rheology & texture, dilution and dissolution characteristics, and make purchasing choices accordingly.
During manufacture liquid structure formation is governed by the underlying phase and colloidal behaviour, and the transient temperature, flow and concentration conditions which exist. Of course in batch mixing vessels the range and persistence of these transient conditions is far more complex than within short residence-time continuous mixing equipment. However, it is important to focus on the relevant mechanisms and kinetics of structure formation, if one is to choose the most appropriate process configuration.
These points are exemplified with reference to new studies of polymer surfactant structuring systems, and the application of in-situ observations of structural changes using microfluidic techniques.