Characterization of the key aroma compounds in a novel Qingke baijiu of Tibet by GC-MS, GC×GC-MS and GC-O-MS

As a local specialty of Tibet, Qingke baijiu (QB) is made from highland barley, and is referred to as the manufacturing process of light-aroma baijiu. Using highland barley in the Qu-making and the high-temperature stacking process of sauce-aroma baijiu results in a novel Qingke baijiu (NQB). This study analyzed two kinds of NQBs by GC-MS, GC×GC-MS, and GC-O-MS, and compared them with QB, light-aroma, strong-aroma, and sauce-aroma baijiu. A total of 346 volatile compounds and 60 aroma-active compounds were detected in NQB. There were 14 compounds with FD≥27 and OAVs ≥1. Although NQB and QB shared 39 volatile compounds, NQB has more than three times the overall concentration of volatile compounds than QB. In contrast to QB, NQB exhibited a richer flavor profile and a more intense fruity, floral, and acidic aroma. Meanwhile, the distilled grains and sorghum aroma were comparatively diminished.