Extensive "Heart-Cut" 2D GC-MS/Olfactometry, Complementary to Aroma Extract Dilution Analysis, Odor Activity Value...

Grains are widely used for the fermentation of spirits, including baijiu. Wuliangye is one of the most renowned baijiu brands, fermented from a blend of five grains: sorghum, wheat, corn, rice, and glutinous rice. To understand the aroma contribution of the raw grains to the product quality, the aroma compounds of "five-grain" were comprehensively investigated by aroma extract dilution analysis (AEDA), "heart-cut" 2D gas chromatography-mass spectrometry/olfactometry (2D GC-GC-MS/O), and comprehensive gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). Thirty-four aroma-active compounds identified in the grains, primarily aldehydes, were further investigated using odor activity values (OAVs), aroma recombination, and omission studies. The results demonstrated that (E,E)-2,4-decadienal, 2-acetyl-1-pyrroline, (E,Z)-2,6-nonadienal, (E)-2-nonenal, (E,E)-2,4-nonadienal, trans-4,5-epoxy-2(E)-decenal, hexanal, and methional were the compounds in "five-grain" important to baijiu aroma. Understanding the origin and fate of these compounds will aid in further research and quality control of this renowned baijiu brand.