Abstract: 【Background】Foxtail millet production areas in China were divided into four regions: the Northeast China region, the North China region, the Inner Mongolia plateau region, and the Northwest China region. The regional trials aimed to screen germplasm resources with good genetic traits. However, good growth genetic traits and foxtail millet grain appearance phenotypes do not necessarily have good culinary quality and aroma characteristics, especially the aroma characteristics largely affect its production and downstream industries. Simultaneous distillation extraction (SDE) is a pretreatment method that simulates the cooking process of porridge and is suitable for the aroma analysis of foxtail millet.【Objective】In order to clarify the aroma characteristics of cereal germplasm resources in different ecological regions and to promote sensory-oriented breeding-processing industrial practices.【Method】Simultaneous distillation extraction-gas chromatography-mass spectrometry (SDE-GC-MS) combined with odor activity value (OAV) method was used to analyze the differences in aroma components of foxtail millet in different regions of China.【Result】 Results showed that a total of 81 volatile substances were detected in 12 foxtail millet varieties from four ecological regions, 25 aldehydes, six alcohols, four phenols, 11 ketones, 11 hydrocarbons, 13 benzene-containing derivatives, four acids, and seven others. The comparison of the results showed that the volatile substance subclasses were similar in different regions, but the contents of the components were different. Thirty-seven volatile components with literature-accessible odor characterization were labeled, and 23 contributing aroma compounds with OAV > 1 were identified in the 12 foxtail millet varieties. The effective discrimination model of the cereal regional test was established by orthogonal partial least squares discrimination analysis (OPLS-DA), and the 12 foxtail millet varieties were classified into three categories, and 18 compounds with VIP > 1 were screened out: hexanal, heptanal, (Z)-2-heptenal, benzaldehyde, (E, E)-2, 4-decadienal, 2, 4-decadienal, nonane, tetradecanoic acid, (Z, Z)-9, 12-octadecadienoic acid, pentadecanoic acid, n-hexadecanoic acid, 2-methoxy-4-vinylphenol, 2, 4-bis(1, 1-dimethylethyl)-phenol, 2, 5-bis(1, 1-dimethylethyl)-phenol, 1-heptanol, nerolidol, 2-pentyl-furan, and hexadecanoic acid methyl ester that could be used to distinguish the differences between different samples.【Conclusion】 SDE-GC-MS combined with OAV identification analyzed the flavor components and characteristics of key aroma compounds of foxtail millet from different ecological regions, and the PLS-DA model screened 18 VIP compounds that distinguished the flavor differences of foxtail millet from different samples and ecological regions. The results of the study provide data references for understanding the differences in flavor characteristics of foxtail millet grown in different regions of China, and for a basis of flavor-oriented foxtail millet variety selection, breeding, and processing.

Key words: simultaneous distillation extraction, foxtail millet, odor activity value, ecological regions, orthogonal partial least squares discriminant