Effect of Temperature on Flavor Substances of Yak Meat during Roasting as Analyzed by Chromatography-Ion Mobility Spectrometry and Chemometrics

In order to explore the difference in flavor among yak leg meat roasted at different temperatures, sensory evaluation, gas chromatography-ion mobility spectrometry (GC-IMS), relative odor activity value (ROAV), partial least squares-discriminant analysis (PLS-DA), and principal component analysis (PCA) were used in this study. The results showed that the samples roasted at 240 ℃ for 7 min had the highest (E) sensory evaluation score. A total of 82 compounds were identified by GC-IMS, including 15 aldehydes, 12 alcohols, 24 lipids, 14 ketones, 7 heterocycles, 3 olefins, and 7 other compounds. The total amount of these compounds in sample E (240 ℃) was the highest, followed by samples D (180 ℃) and C (120 ℃). The total amount of these compounds in sample F (300 ℃) was lower than that in sample E (240 ℃). The key flavor compounds of roasted yak meat were ethyl 2-hydroxypropanoate, 4-methylguaiacol, 2-acetyl-1-pyrroline, 5-nonanone, ethyl salicylate, 1-propanol, (E,E)-2,4-heptadienal, 1-penten-3-one, (E)-2-heptenal, linalyl acetate, butanol-D, methional-M, 2-ethyl-6-methylpyrazine, 4-hexen-1-ol, (Z)-4-decenal, 2,4-heptadienal, 2-phenylethanol, and ethyl butyrate. Sample E had roasted meat-like, fatty, flowery and fruity aromas, which was the best among these five samples. The flavor of samples C and D was lower than that of sample E, having nutty, toasty, sweet and smoked aromas.