COMBINED MEASUREMENT OF FOOD TASTE AND CONSUMER PREFERENCE IN THE INDIVIDUAL - RELIABILITY, PRECISION AND STABILITY DATA

A cognitive theory of quantitative judgement that unites sensory methods into one general type of consumer test is applied to the assessment of individuals' preferences for the level of salt in bread and levels of sugar in a chocolate, a lime drink and a tomato soup. The theory is that each assessor knows rather precisely what levels of sensed characteristics she or he likes in a familiar food or drink and that, in the absence of contextual biases, ratings relative to stable anchor categories of choice behavior are linear with discriminable differences in the described characteristic. Since Weber's difference discrimination ratio is constant over intermediate concentrations of salt and sugar, this implies linear rating against the logarithm of concentrations and such linearity was indeed found in food saltiness and sweetness ratings under conditions of minimal contextual biases on the expression of sensory preference. Also as predicted, a mid-response category of the most acceptable salt or sugar level and two rejection end-categories were used highly consistently as anchors, yielding reliable and precise judgments of tastant level within a bias minimized multi-sample session. A high repeatability of ratings from one session to the next (and not because of memory effects) confirmed the sensory reliability of this method and provided evidence of temporal stability of food taste preferences. Thus it is feasible to estimate an individual consumer's taste preference characteristics from responses to a few food samples.