Analysis of Volatile Flavor Characteristics of Popcorn Chicken with Different Frying Times Using Gas Chromatography-Ion Mobility Spectrometry and Electronic Nose Combined with Chemometrics

The volatile flavor compounds of popcorn chicken were identified using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The overall odor characteristics of popcorn chicken samples with different frying times (2, 2.5, 3, 3.5, and 4 min) at 180 ℃ were distinguished using an electronic nose (E-nose), and the characteristic substances were analyzed using chemometrics. The results showed that a total of 74 volatile flavor compounds were identified. As the frying time increased, the contents of aldehydes, olefins, and heterocyclic compounds gradually increased. E-nose data could effectively distinguish the overall odor profiles of popcorn chicken samples with different frying times and there were differences in E-nose sensor response for them. Based on relative odor activity values (ROAVs), 14 key volatile flavor compounds were identified, among which 2,5-dimethylpyrazine, pentanal, propanal, and 3-methylbutanal had higher contribution rates for each sample. Partial least squares discriminant analysis (PLS-DA) identified six important markers, namely hexandehyde, pentanal, propanal, 2-pentanone, (E)-2-hexenal, and pyrazine, as characteristic volatile flavor compounds in popcorn chicken samples with different frying times.