Metabolomics-based analysis of key nutritional quality, volatile profiling and key odor-active compounds in representative foxtail millet varieties from Shanxi Province.

To reveal the regulatory mechanisms between nutritional components and aroma formation in foxtail millet, five representative varieties from Shanxi were analyzed via multiple metabolomic approaches. CNQX showed the highest carotenoid content; ZGQX had the highest thiamine, while ZGFY exhibited the most balanced B vitamin profile; JGFY was prominent in riboflavin and unsaturated fatty acids. A total of 866 volatile metabolites were putatively identified, and nine key compounds with high theoretical odor potential were screened (rOAV≥1, VIP ≥ 1). Ecological correlation analysis revealed that soil pH and available potassium positively correlated with VB1 and VB2, whereas temperature negatively correlated with C22:1n9 (p ≤ 0.05), with major nutrients primarily genotype-dependent. PCA ranked comprehensive PCA-based chemotype score as JG > CN > JF > ZG > ZZ, with distinct chemical patterns across regions. This study provides a theoretical chemical basis for aroma-oriented breeding and production area planning.