What Is the Basis for Sweetness Synergy?
The biochemical basis for the phenomenon of sweetness synergy is also not known. It has long been known that aspartame and cyclamate are synergistic in sensory experiments (16). Xu et al. (8) have demonstrated that the sweetener receptor has separate orthosteric sites for aspartame and cyclamate, and thus it seems reasonable that a cooperative binding effect may explain aspartame/cyclamate synergy. It is noteworthy that there are many other synergistic sweetener combinations. Exemplary are saccharin and cyclamate. Does saccharin/cyclamate synergism require different orthosteric sites? Saccharin and aspartame are also synergistic, however, and if binding cooperativity is the mechanism mediating sweetness synergy, then the sweetener receptor must have at least three orthosteric sites to explain the synergism observed with just these three sweeteners. Sweetness synergy has been observed in other combinations of sweeteners as well, which suggests that the number of orthosteric sites on the
