Effect of fermentation region on the volatile compounds and sensory characteristics of soy sauce mash

BACKGROUND: Regional environmental conditions, particularly temperature, significantly affect the fermentation characteristics of traditional fermented foods. This study investigated how regional variations influence the volatile aroma compounds and sensory aroma attributes of soy sauce mash fermented in different locations in Korea. RESULTS: Soy sauce mash samples fermented over 60 days in Seoul (TS), Nonsan (TNS), Jeonju (TJJ), and Sacheon (TSC) exhibited distinct aroma profiles. Volatile compound analysis using distillation under reduced pressure, liquid–liquid extraction, and gas chromatography–mass spectrometry identified 21 compounds. Notably, TS had significantly higher concentrations of alcohols (e.g., 2-hexanol, 4-methyl-2-pentanol), TNS showed increased levels of isopropenyl acetate and acetone, TJJ exhibited higher levels of 3-penten-2-ol and methyl 4-vinylbenzoate, and TSC was rich in nitrogen compounds such as 2,6-dimethylpyrazine. Sensory descriptive analysis revealed that samples from TS and TJJ shared similar aroma profiles, as did samples from TNS and TSC. CONCLUSION: Mean lowest temperature rather than geographical latitude significantly influenced the aroma characteristics of soy sauce mash, highlighting temperature as a critical environmental factor in traditional soy sauce fermentation.