## 4 Conclusions  
This study comprehensively investigated the physicochemical properties, volatile flavor compounds, and microbial community dynamics during BBP-meju fermentation  
Figure 8: Correlation clustering heat map (**a**) and correlation network diagram (**b**) between dominant microbial genera and key volatiles flavor compounds (VIP \(>\) 1) during BBP-meju fermentation with different salt concentrations. (**a**) The red and blue indicate positive and negative correlation, respectively, and the darker the color, the stronger the correlation; asterisks represent significance, * is \(p<0.05\), and ** is \(p<0.01\). (**b**): blue squares represent key volatile flavor compounds, red circles represent dominant microbial genera, and the yellow solid line and gray dotted line represent positive and negative correlation, respectively, and the thicker the lines, the stronger the correlation.  
with different salt concentrations. Further analysis was conducted on the correlation between the dominant microbial communities and key volatile flavor compounds. The results indicated that the salt reduction contributed to the accumulation of AAN, reducing sugars, FAAs, OAs, and volatile flavor compounds during BBP-meju fermentation, while also increasing the total acid level. High-throughput sequencing results revealed that _Bacillus, Staphylococcus, Aspergillus_, and _Mortierella_ were the dominant microbial communities during fermentation. Except for _Aspergillus_, their relative abundance was elevated in salt-reduced fermentation and positively correlated with several high-quality flavor compounds. However, the presence of higher levels of opportunistic pathogens in the low-salt meju posed a threat to the safety of the final product. These results provided a theoretical basis for the quality and safety control of BBP during salt-reduced fermentation, as well as a guideline for further developing the low-salt fermented food industry.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods13132108/s1](https://www.mdpi.com/article/10.3390/foods13132108/s1)]([https://www.mdpi.com/article/10.3390/foods13132108/s1](https://www.mdpi.com/article/10.3390/foods13132108/s1)), Figure S1: PLS-DA diagram results of volatile flavor compounds during fermentation of BBP-meju with different salt concentrations; Figure S2: Rarefaction curves and Shannon index curve for bacteria (a,b) and fungi (c,d); Table S1: The \(\alpha\)-diversity of the bacterial and fungal community during fermentation of BBP-meju with different salt concentrations.  
Conceptualization, Q.G.; methodology, J.P. and J.Z.; software, J.Z. and J.L.; validation, Q.G., Y.H. and B.S.; formal analysis, J.P. and J.L.; investigation, J.P. and J.L.; resources, Y.H.; data curation, J.P. and J.Z.; writing--original draft preparation, Q.G.; writing--review and editing, J.P., J.Z., Y.H. and B.S.; visualization, J.Z. and J.L.; supervision, Q.G., Y.H. and B.S.; project administration, B.S.; funding acquisition, Q.G. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Natural Science Foundation Program of Sichuan Province, grant number 2023 NSFSC1205, and the Talent Introduction Project of Xihua University, grant number Z211045.  
Not applicable.  
The original contributions presented in the study are included in the article and Supplementary Materials, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.