Sensory discriminability of older consumers: Interaction between evaluation method, number of samples, and age-related characteristics.

Sensory evaluation conducted by older consumers requires careful methodological consideration due to age-related changes in sensory and cognitive functions, including reduced sensitivity to taste, as well as declines in cognitive processing, memory, and attention. This study investigated the effects of evaluation methods and the number of samples on the sensory discriminability and repeatability of older consumers, categorized into active seniors (AS; 50-64 years) and seniors (S; ≥65 years). Eighty participants (AS: n = 37, S: n = 43) evaluated bulgogi for liking and intensity using a 9-point scale, ranking test, and paired comparison test across two conditions (three vs. six samples). Participants also assessed each method for ease of use and acceptance, and identified their most preferred approach. Results revealed that sensory performance was significantly influenced by the interaction between age, method, and sample number. The AS group most effectively detected sample differences using the 9-point scale. Conversely, the S group showed limited discriminability with the 9-point scale but improved significantly through relative methods. Individually, the 9-point scale yielded the highest response repeatability, whereas the ranking test maximized discrimination between distinct samples. As sample numbers increased, the ranking test intensified the psychological burden due to task complexity, while the paired comparison test induced physical burden in the form of sensory fatigue. These effects were more pronounced in the S group. Nevertheless, the paired comparison test was most frequently preferred for its structural simplicity. These findings suggest that, in sensory evaluation involving older consumers, it is important to consider the structural characteristics of evaluation methods and the number of samples.