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In order to investigate the characteristics and differences of flavor substances in Jiangxiangxing Baijiu with different processes (Kunsha, Suisha, Fansha and Chuansha), the contents of total acid, total ester, skeleton flavor substance and odor activity value (OAV) and principal component analysis (PCA) were analyzed. The results showed that the average content of total acid and total ester in Kunsha compared to other process was the highest with significant differences. Meanwhile, the analysis of flavor substances revealed that the flavor substances contents of acids, esters and alcohols in Kunsha were higher than those in the other three groups, and the total content of aldehydes in Fansha was higher than that in Kunsha. In addition, through the PCA of flavor substance content, it was found that different process Jiangxiangxing Baijiu could be distinguished, among which Kunsha had the best clustering effect. The flavor substances that contributed most to it were phenylethyl acetate, ethyl caproate, caproic acid, ethyl palmitate, 2,3-butanediol (meso) and benzaldehyde. OAV demonstrated that ethyl valerate, ethyl caproate, acetaldehyde, acetal and isovalerate contributed significantly to the aroma of Jiangxiangxing Baijiu, and the number of flavor substances with aroma contribution in Kunsha was higher than that in other processes.

In order to increase and stabilize the content of tetramethylpyrazine in liquor, 13 strains of Bacillus were isolated from Maotai Daqu samples, and 5 strains with excellent protease production were selected through the preliminary screening of protease transparent circle test. After a liquid fermentation test, a functional bacterium with high yield of tetramethylpyrazine was screened out. The content of tetramethylpyrazine in the fermentation broth was 12.22 mg/L, which was identified as Bacillus licheniformis GTBL-168. The seed culture solution of this strain was inoculated into the sauce-flavor liquor accumulation culture at 0%, 3%, 5%, and 7% (v/w) to synergize the fermentation with traditional Daqu, and accumulate acetoin and tetramethyl in the glutinous rice grains. The content of pyrazine increased, and the increasing was the largest when the inoculation amount was 7%, and the yield of tetramethylpyrazine increased by 24.88% compared with the control group, the overall changes in physical and chemical indexes were obvious, and the amino nitrogen and total acid increased, the addition of Bacillus licheniformis GTBL-168 had little effect on the microbial structure of the accumulated fermented grains. With the increasing of the inoculation amount, the abundance of Bacillus and other dominant bacteria in the fermented grains also increased. It would lay a foundation for the application of functional bacteria in the process of stacking fermentation.