Identifying precursors of volatile compounds in puffed foxtail millet: Insights from chemical profiling and model system validation

To elucidate flavor formation in puffed foxtail millet, volatile profiles of five cultivars (Shenmuhongjiugu, Zhangzagu 13, Huangjinmiao, Yugu 18, Zhonggu 2) were analyzed. Concurrently, two distinct model systems, simulating the thermal degradation of individual fatty acids in a defatted matrix and the Maillard reaction between amino acids and glucose, were employed to establish precursor-product relationships. Puffing significantly increased aldehydes and heterocyclic compounds, while their fatty acid and amino acid precursors decreased. The model experiments showed that linoleic acid and lysine were identified as the most important potential precursors for aliphatic and heterocyclic volatiles. Notably, the formation of aromatic compounds from both fatty acid and amino acid precursors suggests a common underlying mechanism of pyrolytic cleavage and radical recombination. Collectively, these findings provide a theoretical basis for the precise regulation of flavor quality in puffed cereal products through targeted precursor management.