Metabolic profiling and amino acid evolution in fermented oats: Insights from UPLC-MS/MS and PLS-DA analysis

Abstract

Oats are a nutritious and versatile cereal, but their potential as a functional food can be enhanced through solid-state fermentation (SSF). This study investigates the impact of SSF on the soluble proteins, peptides, molecular weight (M_W), and free amino acids of oats, aiming to explore the complex relationship between amino acid composition and metabolic profiles. By utilizing advanced metabolomics techniques, this study highlights the influence of fermentation on the nutritional and functional properties of oats, providing insights into its potential applications in the food industry. Results showed that fermented samples had lower pH values, soluble protein and peptide, and total amino-acid contents. Additionally, fermentation significantly altered the M_W distribution, as high M_W proteins and peptides decreased while medium and small M_W increased. Similarly, fermentation changed amino-acid composition, increasing the proportions of sweet and umami amino acids while decreasing the bitter amino acids, enhancing the oats-based food taste. Moreover, based on the KEGG database, a number of metabolic pathways were identified in the fermented oats, and protein metabolism was found to be more active. Correlation analyses revealed complex relationships between amino acids and various metabolites, providing insights into the biochemical mechanisms that shape oat taste profiles during fermentation.