Comparison of nutritional compositions of foxtail millet from the different cultivation regions by UPLC‐Q‐Orbitrap HRMS based metabolomics approach

Foxtail millet (Setaria italica (L.) P. Beauv) is cultivated throughout most parts of Shanxi province. Although quite a number of reports have been conducted on the bioactivities of foxtail millet, little information was available on the metabolite differences of the foxtail millet seeds from different cultivation regions. In this study, a systematic study on the metabolite composition of the foxtail millet seed from Shanxi province was conducted by ultra-high performance liquid chromatography combined with electrospray ionization quadrupole/orbitrap high-resolution mass spectrometry, and 158 compounds were characterized through analysis of mass fragmentation patterns and comparison with the data in the databases and literatures. Then the metabolomic analysis, in combination with heatmap and hierarchical clustering analysis revealed the significant differences between the foxtail millet from northern and southern Shanxi province, which was ascribed to 20 differential metabolites. Then metabolic pathway analysis was performed based on these differential metabolites, and three metabolic pathways were selected as the key contributors. The results showed that foxtail millet from different cultivation regions showed obvious metabolite differences, which was probably related to environmental factors. In addition, the findings also provide an important reference for further research on the functional food development from foxtail millet. PRACTICAL APPLICATIONS: Foxtail millet (Setaria italica (L.) P. Beauv) as a staple food among the majority of people, is rich in bioactive nutrients, including free fatty acids, triglycerides, cellulose, protein, vitamins, and polyphenol, et al. The metabolite composition of the foxtail millet seed was investigated systematically and the results showed that the climate conditions can directly affect the metabolite composition of foxtail millets, and provided important reference for the further research on the resource utilization and functional food development from foxtail millet.