Manipulating oral behaviour of food emulsions using different emulsifiers

This study aims to investigate the assumption that the presence of alpha-amylase in the human saliva will interact instantly with starch and will lead to very different oral behaviour and enhanced flavour release. Hence, orange oil flavoured emulsion was prepared with whey protein isolates (WPI) and modified starch (MS). The stability and flavour release of emulsions were examined through invitro and invivo studies. MS emulsion mixed with artificial saliva containing alpha-amylase resulted in more pronounced changes in mean particle size from 0.185 to 2.35 mu m and a significant increase in viscosity. Morphology and turbidity revealed strong flocculation, coalescence and creaming. However, WPI emulsion exhibited very little changes in stability and behaviour. Similar results were observed during oral digestion (invivo) for both emulsion systems. Moreover, a higher intensity of flavour release (37%) was observed in MS emulsion than WPI. This work demonstrated that a starch-stabilised emulsion has a very different oral behaviour to that of a protein-stabilised emulsion.