Influence of visual appearance on consumer perception of spiciness in kimchi

The objective of this study was to determine the effect of appearance on consumer perception of spiciness in kimchi. Three kimchi samples with different levels of red pepper powder (1.5, 3, 6%; K1, K2, K3) were prepared. A 2-day consumer testing was conducted with 2 weeks interval and participants (n = 108) evaluated kimchi with (Day 1) and without (Day 2) blindfold. Day 1 experiment was conducted without providing appearance about the kimchi sample by covering the eyes of the participants using the eye patch, and Day 2 experiment was conducted by allowing the participants to see and evaluate the kimchi sample directly without covering their eyes and evaluated. When evaluated with blindfold, no differences were observed in all liking attributes (p >.05) except for overall liking score, indicating decreased sensitivities without appearance. When evaluated without blindfold, K1 received lowest appearance and color liking scores than other samples (p <.05). Regarding spiciness liking, interaction between sample and evaluation condition was observed in which spiciness liking of K1 was lower in informed condition in comparison to blind evaluation (p <.05), while spiciness liking of other samples was higher under informed condition. Appearance-related attributes such as color of kimchi may influence the overall and spiciness perception of kimchi. Finding from this study emphasizes the importance of appearance on consumer acceptability of spiciness in kimchi. Therefore, the results of this study will be able to identify the color and the amount of red pepper powder that consumers prefer and be used in manufacturing. Practical applications: Spiciness is one of the key sensory characteristics in kimchi, and capsaicin in red pepper powder as part of ingredient is responsible for spiciness. However, measuring pungent spiciness in kimchi is heavily dependent on instrumental analysis of capsaicin content; therefore, consideration on human perception on spiciness in complex food matrix was not fully considered. This study focused on consumer perception on spiciness in kimchi in different evaluation condition and found that the appearance may influence consumer perception of pungent spiciness in kimchi. Finding from this study suggests the importance of human factors in evaluation of pungent spiciness in kimchi.