Dynamic aroma evolution of peach juice during thermal processing: Integrating volatilomics and non-volatile...

Flavor quality is a critical determinant of consumer acceptance of peach juice (PJ). However, the dynamic evolution of aroma compounds and their relationships with non-volatile precursors during thermal processing remains insufficiently understood. This study employed an integrated analytical strategy combining quantitative descriptive analysis (QDA), electronic nose, HS-SPME-GC/MS-based volatilomics, and non-targeted metabolomics to systematically elucidate aroma evolution and its associations with non-volatile metabolites in PJs subjected to thermal processing. Sensory evaluation and volatile analysis revealed a clear stage-dependent and dynamic aroma trajectory, in which moderate heating significantly enhanced desirable peach-like, floral, sweet, and creamy notes, while excessive heating induced off-flavors. Notably, the 12-min treatment (PJ4) exhibited the most favorable aroma profile among the tested treatments while satisfying commercial sterility requirements. Totally 59 volatiles were identified, and combined with GC-O/AI and odor activity values (OAV), 10 key aroma-active compounds, involving γ- and δ-lactones, linalool, and β-ionone, were recognized as key contributors to aroma quality during the mid-heating stage. Metabolomics revealed 1150 non-volatile metabolites following a three-stage dynamic pattern. Integrated KEGG and correlation analyses indicated stage-dependent shifts in metabolites annotated to lipid-, amino acid-, and carbohydrate-related pathways, which were associated with changes in potential aroma precursor pools and aroma-active compounds. These findings provide mechanistic insights into aroma evolution during thermal processing and a basis for further evaluation of flavor optimization strategies in peach juice processing.