Geographical differences in aroma profiles and key volatile compounds associated with sauce-like aroma of high-salt liquid-state fermented soy sauce

Geographical differences in the aroma profiles of high-salt liquid-state fermented soy sauce (HLFSS) and its sauce-like aroma remain underexplored. A total of 63 HLFSS samples were collected from four representative production regions: Southern China, Southwestern China, Northern China and Japan. Trained panelists evaluated the aroma characteristics and overall flavor of these samples using the Rate-All-That-Apply (RATA) method. HS-SPME-GC-MS was employed to extract and identify the aroma compounds of HLFSS, while network analysis was used to establish correlations between aroma compounds and their corresponding sensory characteristics. Omission tests were further conducted to verify the key aroma compounds. The results showed that geographical differences significantly affected aroma profiles of HLFSS, including the perceived intensity of aroma descriptors, overall flavor, aroma compound concentrations and key volatile compounds. A total of 102 characteristic aroma compounds were identified across all samples. OAV analysis identified 15 key aroma compounds (OAV > 1), and PLS-DA screened 15 potential marker compounds (VIP > 1) for distinguishing HLFSS from different production regions. Network analysis further revealed that the sauce-like aroma was positively correlated with 2,3,5-trimethylpyrazine, HDMF, and HEMF. We suggest that such differences are presumably attributed to variations in raw materials, fermentation processes and microbial diversity across regions.