Using classical psychophysics to determine ideal flavour intensity

In Experiment 1 a classical psychophysical method, the method of constant stimuli, is adapted to determine the most preferred flavour intensity of an orange drink. Twentyfive assessors were each presented with five concentrations of the drink, and were required to respond either ‘too strong’ or ‘not strong enough’, the notional concept of ideal‐intensity serving as the standard in the comparison. All assessors exhibited an ideal‐point within the stimulus range presented, and the overall estimate of optimum concentration was close to that of previous work. In Experiment 2, the method of constant stimuli was applied in orthodox manner, with the optimum concentration (as determined from Experiment 1) physically presented as the standard in a series of paired comparisons. Assessors were required to identify the stronger drink within each pair. The estimates of discriminability in Experiments 1 (the ‘hedonic’ just noticeable difference) and 2 (the conventional just noticeable difference) were found to be almost identical.