Assessment of the taste interaction between two qualitatively similar-tasting substances: a comparison between comparison rules.

The taste interaction between sucrose and fructose was assessed by using three different comparison procedures: the summated response comparison, the factorial plot comparison, and the equimolar comparison rule. The perceived sweetness intensities were obtained on a ratio scale by using a functional measurement approach in combination with a two-stimulus procedure. The conclusions obtained from each of the three comparison rules were identical. The taste interaction between sucrose and fructose could be explained to a large extent, but not completely, by the apparent taste "interactions" within sucrose and fructose as single substances. It is argued that the apparent taste interaction within a large number of single sugars and between two of these sugars in a mixture is somewhat synergistic at low sweetness levels, additive at intermediate sweetness levels, and suppressive at high sweetness levels.