Abstract :

The role of water in sweet taste chemoreception of small carbohydrates and artificial sweeteners was derived from physico-chemical methods and spectroscopic studies of their aqueous solutions. Likewise, surface tension, contact angles with a hydrophobic surface, and the adhesion forces to this type of surface of the aqueous solutions of sapid molecules were found to discriminate between their effects on water cohesion and also between their taste qualities. In the present study, surface tension (ST) and Apparent Specific volume (ASV) for bitter molecule (Nicotine) and bitterness inhibitors (sugars, polyols, salts) and Nicotine-Inhibitor mixtures were investigated at air-water interface using "dynamic surface tension" method in order to determine the role of water structure in the mechanism of unpleasant taste inhibition. The ST method was chosen since it provides reliable, sensitive and convenient means of investigating the adsorption of molecules at an interface. The ASV offer direct experimental verification of computed volumes and, measures of the effective volumes of sapid solutes in the vicinity of receptor sites. The value of Apparent Specific Volume (ASV) proves to be a good discriminator of tastes. The results of the present study allow to conclude that surface tension values are a good tool to classify inhibitors in three classes: molecules with antagonist effect (AMP) on Nicotine adsorption at the interface, molecules with negligible effect (Sucrose, Aspartame, Acesulfame-K, K-Gluconate, -Cyclodextrin), molecules with enhancement effect on the adsorption of Nicotine at air/solution interface (Maltitol, Palatinit*, Na-Gluconate and Furaneol).