Abstract: To investigate the formation mechanism of the flavor characteristics of Sichuan cuisine’s signature “replicated composite soy sauce”, five commercial soy sauces were used to prepare “replicated composite soy sauce” samples. The changes in their chemical composition were analyzed using an electronic tongue (E-tongue), an electronic nose (E-nose), and gas chromatography-ion mobility spectrometry (GC-IMS). E-tongue results indicated significant differences in sourness intensity among samples, while the E-nose effectively distinguished their aroma profiles. GC-IMS analysis detected a total of 68 compounds. Terpinolene, limonene, myrcene, β-pinene, α-phellandrene, and 1,4-cineole were found to originate from scallions, ginger, and dried spices, indicating that adding spices during processing enhanced the flavor complexity. During processing, terpenes from spices underwent thermal transformation, while brown sugar and amino acids in soy sauce participated in the Maillard reaction and Strecker degradation, generating ketones, alcohols, heterocyclic compounds, and sulfur-containing flavor substances. Among them, 2,3-butanediol, 2-methylbutanol, and isobutanol from brown sugar contributed to sweet aroma notes, which helped reduce the perception of saltiness. Partial least squares regression (PLSR) analysis showed that the addition of spices and brown sugar significantly enhanced the overall flavor complexity and taste layering of “replicated composite soy sauce”. This study provides a theoretical basis for the standardized production and flavor modulation.

Key words: replicated composite soy sauce; electronic nose; electronic tongue; gas chromatography-ion mobility spectrometry; flavor profile; chemometrics