Theoretical note: tests of synergy in sweetener mixtures

Some methods for examining the additivity of sweeteners, and their synergy in mixtures depend upon setting component concentrations on the basis of sweetness equivalence, usually to a sucrose reference. These methods may under- or over-predict the sweetness of a mixture, leading to spurious claims of synergy or mixture suppression. This paper points out one problem with one such popular method, in that the method can lead to a conclusion that a substance would synergize with itself. To the extent that self-synergy is an illogical conclusion for a mixture comparison, such a method should be avoided in tests of synergy. The sweetness equivalence approach is contrasted with a simpler approach based on concentrations that does not lead to conclusions of self-synergy.