Exploring hotness and pungent odour thresholds among three groups of Thai chilli users

Abstract

SummarySensory thresholds of hotness and pungent odour were determined from 120 chilli users. Three groups of Light (L), Moderate (M), and Heavy (H) chilli users were categorised based on their chilli consumption habits and sensitivity to hotness standard solutions. After the screening test, the users participated in 12 Alternative Forced Choice (AFC)‐sets, for each of three stimuli (capsaicin and 1‐Penten‐3‐One (1P3O) odour and dried chilli powder). The dried chilli 3‐AFC sample's concentration range was calculated to equate the same range of standard capsaicin stimuli for hotness sensation measurements. Concentrations of the three stimuli tested were in a range of (0.08–16.80 dry basis g L−1) for standardised dried chilli powder, (0.10–20.16 mg L−1) for capsaicin, and (0.01–2.04 μL L−1) for 1P3O. Heavy chilli users group threshold, as anticipated, indicated the highest average recognition level of stimuli in terms of pungency odour perceived from dried chilli (5.88 g L−1) and 1P3O (1.34 μL L−1), as well as for hotness sensation from dried chilli (7.19 g L−1) and capsaicin (12.79 mg L−1) samples. The magnitudes of heavy user's thresholds were exponentially higher than that of light users. At the recognition thresholds of oral hotness perception, the level of capsaicin presented in dried chilli sample was found to be much lower than the concentration of standard capsaicin sample. It was concluded that pungent odours and other flavours in dried chilli, increase hotness perception as compared with capsaicin stimulus. We also confirmed that 1P3O contributes to chilli pungent odour.