Differential effects of packaging materials on the evolution of volatile and non-volatile compounds in soy sauce...

The selection of packaging materials is critical for maintaining the flavor quality of soy sauce during its shelf life. However, a systematic understanding of their impact on the evolution of both non-volatile taste [including free amino acids, nucleotides, equivalent umami concentration (EUC) and organic acids] and volatile aroma compounds over long-term storage remains lacking. Therefore, the present study systematically compared the dynamic changes between plastic bottles (PB) and glass bottles (GB).

Principal component analysis showed time as the primary driver of flavor compound degradation, with packaging effects emerging mid-storage. GB more effectively delayed the degradation of umami amino acids (especially glutamic acid), maintaining a significantly higher EUC from 0 to 6 months (P < 0.05). Regarding aroma, although the profiles of volatile compounds were similar, their levels decreased over time. Key aroma compounds identified by combined relative odor activity value and aroma extracts dilution analysis analyses showed better preservation in GN. By contrast, PB promoted the accumulation of oxidative off-flavors, such as decanal, and led to a significantly higher final concentration of acetic acid (PB: 61.13 mg mL^-1; GB: 48.31 mg mL^-1, P < 0.05). Correlation analysis revealed significant positive correlations between key aroma compounds and umami amino acids, with stronger associations in PB, suggesting faster coupled flavor degradation as a result of higher oxygen permeability.

For medium-to-long-term soy sauce storage, selecting high-barrier packaging materials, such as glass or materials with equivalent barrier properties, is crucial to minimize flavor degradation and maintain overall sensory quality. © 2026 Society of Chemical Industry.