Effect of tea polyphenols on the dilational rheology of human whole saliva (HWS): part 2, polyphenols-HWS interaction.

In the second part of this communication we screen a few tea polyphenols for their ability to interact with pre-adsorbed salivary proteins at the air-liquid interface. Using interfacial dilational rheology characterisation, we measure the variation in surface elasticity of a pre-adsorbed salivary film after exposure to tea polyphenols solutions in order to probe the degree of mutual interaction. We observe that this interaction with salivary proteins varies according to the chemical structure and degree of polyphenols complexity (number of phenols rings). The evolution of the salivary film after exposure to polyphenol solutions is characterised through surface dilational response to appropriate frequency modulation and the results are analysed using a general mixed kinetic model, which reproduces correctly the experimental data except for the galloylated theaflavins.