Analysis of Volatile Flavor Substances in Mutton Shashlik Based on GC-IMS Technology

In order to establish the characteristic flavor fingerprint of mutton shashlik. In this study, gas chromatography-ion mobility spectroscopy (GC-IMS) was used to measure and analyze the flavor of commercial mutton shashlik bought from 5 barbecue shops. The results showed that: A total of 82 volatile compounds were identified in all samples, including monomers and dimers. The detected compounds were mainly alcohols, ketones, aldehydes, esters, acids, pyrazines, furans, hydrocarbons and sulfur compounds. Among them, the substances shared by all samples were: Aldehydes (pentanal, nonanal, octanal, hexanal, heptanal, 3-methylbutanal, benzaldehyde, methional), ketones (2-heptanone, 2-butanone, 6-methyl-5-hepten-2-one, acetoin, γ-butyrolactone), alcohol (pentanol) and ester (ethyl acetate). By constructing the fingerprints of mutton shashlik baked with and without spices, the similarities and differences of different mutton shashlik samples could be clearly observed. The fingerprints showed that the contents of 6-methyl-5-hepten-2-one in mutton shashlik samples decreased after adding spices while the contents of 2-heptanone, acetone and pentanol increased. In addition, the changes of hexanal, nonanal, heptanal, 3-methylbutanal, benzaldehyde and acetoin were not significant, which might due to that these substances were produced by the meat itself during the grilling process. Principal Component Analysis (PCA) was performed on the samples based on the fingerprints information. Results showed that the characteristics flavor of different mutton shashlik samples were different. Thus, GC-IMS could be used to detect the flavor components of mutton shashlik and conduct multivariate analysis, which would provide a certain theoretical and practical application for the flavor evaluation of mutton shashlik.