Regional tongue sensitivity for sweetness and pungency of ethanol-aspartame mixtures

Binary mixtures of aspartame prepared at three levels of concentration and dissolved in four ethanolic dilutions were perceptually evaluated. Sweet-pungent combinations were presented in solution or in disks of filter paper (paper) soaked in the solutions. Variations in sweetness and pungency were examined at two oral loci including the tip and the back plus the front of the tongue in the liquid condition or the tip and the back of the tongue in the paper condition. A similar behavior was observed in liquid and paper conditions; as the concentration of aspartame and ethanol increased so did the intensity for sweet and pungent qualities. Whereas sweetness was not influenced by ethanol addition (2-8% V/V), a suppressive effect of aspartame (1-4 mM) on pungency was noted for liquid but not for the paper condition. Sweetness was enhanced when the back plus the front of the tongue was stimulated by solutions. Finally, there was a complex pattern of regional effects on the perceived pungency of alcoholic-sweet solutions that was not replicated in the paper condition.