Effects of Different Spices on Microbial Community and Physicochemical Properties in Low-Salt Shrimp Paste

In order to develop new shrimp paste products and expand the shrimp paste market, ginger, cinnamon or perilla was added before fermentation of low-salt shrimp paste in this study. The physicochemical indexes of low-salt shrimp paste were determined, and the effect of spice addition on the microbial community composition and diversity of shrimp paste was explored by high-throughput sequencing technology. The results showed that the contents of moisture and salt in shrimp paste were 51.34%–61.77% and 15.61%–17.71%, respectively. The addition of spices decreased the pH and amino nitrogen content of shrimp paste. The addition of cinnamon and ginger reduced the total volatile basic nitrogen (TVB-N) content by 30.41% and 10.28%, respectively, while the addition of perilla increased the TVB-N content by 9.98%. Compared with the control shrimp paste, the diversity of fungi and bacteria in shrimp paste added with perilla was higher. The addition of cinnamon and ginger decreased the richness of bacterial community and increased the richness of fungal community in shrimp paste. The analysis of differential flora showed that the addition of ginger and cinnamon increased the relative abundance of Tetragenococcus and Wallemia, but reduced the relative abundance of Staphylococcus by 99.32% and 98.14%, respectively. The relative abundance of Penicillium and Aspergillus in shrimp paste added with perilla was higher. Pearson correlation analysis showed that Staphylococcus, Wallemia, Rhodotorula and Penicillium had significant correlations with physicochemical indicators, indicating that these microorganisms play an important role in shrimp paste. To sum up, the addition of spices can change the microbial community composition of shrimp paste, enrich the types of shrimp paste and improve the safety of shrimp paste.