Evolution of Key Flavor Compounds in Sonit Sheep Lamb During Grilling Process Using HS-GC-IMS, E-nose, E-tongue, and Physicochemical Techniques

In this study, the evolution of key flavor compounds in sonit sheep lamb during grilling process has been studied by the E-nose, E-tongue, HS-GC-IMS technique and physicochemical methods. The results showed that the moisture content in lamb decreased, protein content increased due to water loss, fat content reduced due to thermal degradation during the grilling process. The pH showed an initial rapid decrease with significant differences at various grilling times (P < 0.05). The E-nose and E-tongue were found effective in distinguishing lamb samples during grilling duration. A total of 83 volatiles were identified by HS-GC-IMS. Among them, 29 flavor compounds with VIP > 1 were identified as the key flavor substances using the OPLS-DA model. Ethyl acrylate was the main characteristic flavor compounds in raw Sonit Sheep lamb, while ethanol and 1-butanol were determined as the key flavor compounds at 3 and 6 min. Ethylpyrazine, (E)-2-octenal, and nonanal are key substances at 9 min grilling. When grilled for 12 min, the flavor compounds such as 2-methylpropanal, ethyl ethanoate, and trimethylpyrazine became the most important flavor compound in the grilled lamb.