Vessel-dependent changes in antioxidant and flavor profiles of soy sauce mash during 60-day fermentation

BACKGROUND: Fermentation vessels play a crucial role in modulating the chemical and sensory properties of fermented foods, yet limited studies have addressed how vessel type affects soy sauce mash, the precursor to traditional soy sauce. This study examined the influence of two vessel types – Korean onggi and plastic containers – on the functional and sensory quality of soy sauce mash during 60 days of fermentation. RESULTS: Significant differences were observed between vessel types in salinity, amino nitrogen, total polyphenol content, and aroma profiles. Unexpectedly, mash fermented in plastic vessels exhibited higher antioxidant activity and amino nitrogen content, suggesting enhanced microbial metabolism under oxygen-restricted conditions. Sensory profiling revealed distinct aroma descriptors for each vessel type, with plastic-fermented mash characterized by ‘black taffy’ and ‘green’ notes, in contrast to ‘honey’ and ‘rancid’ notes for onggi. CONCLUSION: These findings challenge the conventional assumption that traditional porous vessels such as onggi consistently yield superior quality in fermented soy products. Instead, our results suggest that plastic containers, often considered secondary for their convenience, can promote desirable chemical and sensory outcomes under certain fermentation conditions. This study offers new insights into how vessel type can shape fermentation functionality, and serves as a basis for informed container selection in both artisanal and industrial contexts.