Investigation on Quality Discrepancies of Soy Sauce Aroma Baijiu: Flavor Chemical Characteristics in Single-Source and Cross-Source Samples

Assessing the quality of Soy Sauce Aroma Baijiu (SSAB) is a complex task due to the multitude of production factors and manufacturer preferences. This complexity is further amplified when comparing products from different manufacturers, as stylistic variations can overshadow intrinsic quality differences. To address this, our study introduces a single-source to cross-source quality gradient analysis methodology. By integrating aroma sensory analysis with multivariate chemometrics, we markers for SSAB quality grading were identified comprehensively. Totally 24 quality grade markers were identified through both single and cross-source analyses. Seven compounds, including 2-heptanol, hexyl hexanoate, and isopentyl hexanoate, showed a positive correlation with SSAB quality in single-source analyses, enhancing sensory attributes of grassy, floral, sweet, and acidic aromas in D-grade samples. The remaining 17 markers improved the perception of grassy, floral, sour, and roast aromas in the reconstitution mixture of skeletal compounds while reducing sweet aroma ratings. The integration of single-source and cross-source analyses, along with chemometric techniques, establishes a reliable and objective framework for SSAB grading, which can be applied to other alcoholic beverages as well.