Identification of volatile flavor substances in four key muscle portions of five Tibetan sheep breeds.

Backgroud: To clarify the variations in flavor characteristics among various Tibetan sheep breeds (Gangba, Huoerba, Sewa, Duoma and Awang) across different mutton portions (M. longissimus thoracis et lumborum, topside, thick flank and shoulder fillet), HS-SPME-GC-MS and HS-GC-IMS were performed with multivariate statistical analysis to characterize the volatile organic compounds (VOCs) in Tibetan sheep mutton.

Results: The results identified 89 and 75 VOCs using HS-SPME-GC-MS and HS-GC-IMS, respectively, with aldehydes, ketones and alcohols as the primary compound classes. The main flavor characteristic substances were 1-octen-3-ol, 3-hydroxy-2-butanone, 2,3-pentanedione, acetone, octanal, 2-pentylfuran, nonanal, hexanal, 1-hexanol, 2-butanone, 1-pentanol, heptanal, 2-pentanone, 1-penten-3-ol and benzaldehyde, contributing notes of fruity, floral, grassy, caramel, baking and creamy aromas. The contributing compounds of odor activity value > 1 were successfully determined, enabling the characterization of Tibetan sheep mutton flavor profiles. Fingerprints were applied to distinguish common and unique VOCs across different mutton portions from the studied breeds. Samples were effectively categorized by principal component analysis and partial least squares discriminant analysis (PLS-DA) according to their aroma characteristics, and a stable model (variable importance in projection (VIP)) was established through PLS-DA, highlighting hexanal, 1-hexanol, 2-butanone, 1-pentanol, heptanal, 1-octen-3-ol, 3-hydroxy-2-butanone, 2-pentanone, octanal, ethanol, acetone, 1-penten-3-ol, 2,3-pentanedione and acetic acid with VIP > 1.

Conclusion: The findings reveal the VOC profiles of various mutton portions of Tibetan sheep breeds, offering insights for product development and enhancing the understanding of flavor in Tibetan sheep meat products. © 2025 Society of Chemical Industry.