Investigation of synergism in binary mixtures of sweeteners.

The purpose of the present study was to determine the presence and degree of synergism among all binary mixtures of 14 sweeteners varying in chemical structure. A trained panel evaluated binary combinations of the following sweeteners: three sugars (fructose, glucose, sucrose), two polyhydric alcohols (mannitol, sorbitol), two diterpenoid glycosides (rebaudioside-A, stevioside), two dipeptide derivatives (alitame, aspartame), one sulfamate (sodium cyclamate), one protein (thaumatin), two N-sulfonyl amides (acesulfame-K, sodium saccharin), and one dihydrochalcone (neohesperidin dihydrochalcone). Each sweetener was tested at three concentrations that were isosweet with 3%, 5%, and 7% sucrose. Two methods of analysis were performed to determine synergistic effects. In Method I, an ANOVA was performed for each intensity level to determine if the mean sweetness intensity ratings of each binary mixture were equal to nominal sweetness (i.e., additivity) or not equal to nominal sweetness (i.e., synergism or suppression). In Method II, an additional ANOVA was performed to determine if the sweetness intensity ratings of any given mixture were equal to or greater than the average of the sweetness ratings of the two pure components in that blend.

Adaptation of sweeteners in water and in tannic acid solutions.

Repeated exposure to a tastant often leads to a decrease in magnitude of the perceived intensity; this phenomenon is termed adaptation. The purpose of this study was to determine the degree of adaptation of the sweet response for a variety of sweeteners in water and in the presence of two levels of tannic acid. Sweetness intensity ratings were given by a trained panel for 14 sweeteners: three sugars (fructose, glucose, sucrose), two polyhydric alcohols (mannitol, sorbitol), two terpenoid glycosides (rebaudioside-A, stevioside), two dipeptide derivatives (alitame, aspartame), one sulfamate (sodium cyclamate), one protein (thaumatin), two N-sulfonyl amides (acesulfame-K, sodium saccharin), and one dihydrochalcone (neohesperidin dihydrochalcone). Panelists were given four isointense concentrations of each sweetener by itself and in the presence of two concentrations of tannic acid. Each sweetener concentration was tasted and rated four consecutive times with a 30 s interval between each taste and a 2 min interval between each concentration. Within a taste session, a series of concentrations of a given sweetener was presented in ascending order of magnitude. Adaptation was calculated as the decrease in intensity from the first to the fourth sample. The greatest adaptation in water solutions was found for acesulfame-K, Na saccharin, rebaudioside-A, and stevioside. This was followed by the dipeptide sweeteners, alitame and aspartame. The least adaptation occurred with the sugars, polyhydric alcohols, and neohesperidin dihydrochalcone. Adaptation was greater in tannic acid solutions than in water for six sweeteners. Adaptation of sweet taste may result from the desensitization of sweetener receptors analogous to the homologous desensitization found in the beta adrenergic system.