Analysis of volatile organic compounds (VOCs) in yak ghee from different pastoral areas of China based on GC-IMS

In this study, for the first time, gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze the differences of volatile organic compounds (VOCs) in 12 ghee samples from different pastoral areas of China. A total of 72 VOCs from different pastoral areas were identified in ghee. The topographic maps and fingerprints showed the differences in VOCs in ghee from different pastoral areas of China. It can be found that the ghee in the Xizang pastoral area contained the most esters, and the ghee in the Qinghai pastoral area contained the most ketones. Xizang and Qinghai also had the highest total VOCs, but Gansu had the lowest. In addition, there were significant differences in VOCs between Xinjiang cattle ghee and yak ghee. PLS-DA can distinguish ghee from different pastoral areas. In summary, GC-IMS technology can be used to construct ghee flavor fingerprints in different pastoral areas of China, which provides a theoretical basis and data support for the traceability of ghee origin.