Differentiation of volatile organic compounds in chili powders of different spiciness levels via E-nose, HS-GC-IMS, and chemometrics

Introduction: Chili powder is a widely used seasoning whose pungency largely depends on its capsaicin content and volatile compounds. Methods: This study evaluated the capsaicin levels and pungency of three commercial chili powders labeled light, medium, and strong using a pungency meter. Volatile organic compounds (VOCs) were analyzed via electronic nose and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) coupled with multivariate statistical analyses. Results: Capsaicin concentrations in the medium and strong chili powders were significantly greater than those in the light group (p < 0.01). The Scoville heat unit (SHU) values were 604 (light), 1,585 (medium), and 1733 (strong). The electronic nose successfully differentiated samples on the basis of spiciness level. HS-GC-IMS identified 48 VOCs, mainly aldehydes (51.74-55.55%) and ketones (29.93-32.09%). Variable importance projection (VIP > 1, p < 0.05) highlighted 21 marker volatiles, whereas fold change analysis (FC > 2 or < 0.5) identified 14 differential compounds across sample groups. Key odorants such as (E, E)-2,4-heptadienal, butanal, 3-methylbutanal, and 2,3-butanedione were associated with flavor differences among the chili powders. Conclusion: Chili powders with varying spiciness levels exhibit notable differences in capsaicin content, VOC profiles, and distinctive flavor markers, which can be effectively characterized through integrated sensory and chemical analyses.