Abstract:To fully understand the differences in indicators among various quality levels of jiang-flavour Baijiu, 4 grades of jiang-flavour Baijiu were studied. Using gas chromatography technology combined with sensory evaluation, 64 flavor compounds in sauce-flavored liquor were quantitatively analyzed. By integrating odor activity value (OAV) and chemical metrology, key differentiating compounds were identified. The results showed that the Baijiu samples were ranked by total flavor compound content in the order of B>A>C>D. The A-grade and B-grade Baijiu samples generally contained more flavor compounds than the C-grade and D-grade Baijiu samples. However, the D-grade Baijiu sample contained a higher total amount of aromatic compounds compared to the other three grades. Key differentiating compounds, such as ethyl valerate, valeric acid, ethyl butyrate, butyric acid, and phenylacetaldehyde, were identified through OAV calculations. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to build models for 4 different grades of jiang-flavour Baijiu, achieving a classification accuracy of 97.4% and effectively distinguishing the 4 grades of jiang-flavour Baijiu. Additionally, 27 key differentiating compounds were selected using variable importance in projection (VIP) analysis. A cluster heatmap was generated according to these 27 compounds, and OAV analysis further validated the effectiveness of the VIP selection.
