A dumping effect occurs when panelists perceive an attribute which they are
not asked to rate, and express it on a scale intended for another attribute
(Lawless and Heymann 1998). Based on the significant thickness differences
observation in experiment 11, we know the samples with oil were slightly thicker
than the oil-free samples. Since we asked panelists to rate only taste intensity in
experiment I, they may have expressed this thickness difference by dumping
their thickness perception into their taste intensity ratings.
If dumping occurred in experiment I (and not in experiment I1 where we
provided a separate scale for thickness), we would expect the size of the
difference in taste intensity between the water and oil dilutions to be larger in
experiment I than in experiment 11. This did not happen (Table 4), thus dumping
probably did not affect the findings of experiment I.
When formulating reduced fat or fat-free foods, one can either remove the
fat and add nothing, or replace the fat with another material. Our study did both;
the emulsion was the full-fat version, the control had the fat replaced with
nothing, and the water dilution replaced the fat with another nonlipid material.
The fat reduction strategy determines the effect on taste. We are aware of only
one other study that also did both types of comparisons (Yamamoto and
Nakabayashi 1999). They also observed that fat enhanced saltiness of oil-inwater
emulsions when the full fat was compared to an aqueous fat replacement.
When they subsequently corrected for NaCl concentration differences in the
aqueous phase, they found fat suppressed saltiness. We did not observe this
suppression. When we corrected for aqueous NaCl concentrations (the control
versus oil dilution comparison) we found fat had no effect on saltiness intensity.
Because the level of oil was so high in Yamamoto and Nakabayash’s (1999)
emulsion (70% vs 9-17% in ours), it may have created a barrier between the
aqueous phase and taste receptors.