A good judge of character

摘要

Many foodstuffs are concentrated dispersions of solid particles in a liquid medium or liquid droplets in a liquid medium. The rheological properties of such products give an indication of reproducibility levels and can be correlated with, for example, storage stability, ease of pumping and sensory perception (ie mouthfeel). Often, rheological analysis is performed using rotational viscometers and by measuring viscosity at moderate to high shear rates. Under these circumstances, it is conceivable this analysis would not show subtle differences that may only be obvious at low shear rates. This may manifest itself in aesthetically displeasing syneresis, sedimentation or, worse, a detection of a different 'feel' by the consumer. Modern rheology offers an opportunity to characterise the properties of these materials more precisely.