Impact of capsaicin with individual differences. i) Dendrogram of all 15 participants for CAP solutions and ii) plots of three groups of participants (Group 1, green solid line; Group 2, orange dashed line; Group 3, blue dotted line) based on how often eat spicy food a week, maximum aroma perception, maximum spiciness perception and saliva secretion for CAP solutions. Letter a and b indicated a significant difference between the groups for each factor by Tukey's post-hoc analysis (p < 0.05). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)