In order to explore the effect of clove essential oil on the quality and safety of dry fermented catfish sausage, sausage samples were prepared from catfish surimi added with different amounts of clove essential oil (0% as control, 0.02%, 0.03%, 0.04%, and 0.05%), and their moisture content, water activity (a_w), pH value, color difference, thiobarbituric acid reactive substance (TBARs) value, microbial load, biogenic amine content, nitrite residue, N-nitrosamine content, and sensory quality of dry sausages were determined. The results showed that the addition of clove essential oil had little effect on the moisture content, a_w and TBARs value of dry fermented fish sausages, but it could decrease the a_w compared with the control group. With the addition of 0.05% clove essential oil, the lightness value (L*) of sausages was the highest, and the redness value (a*) was improved with increasing concentration of clove essential oil. The pH value showed a trend of first decreasing and then increasing with increasing concentration of clove essential oil, reaching its minimum at an addition level of 0.03%. The residual amount of nitrite in air dried sausage decreased with increasing addition of clove essential oil, and the maximum inhibition percentage of 38.7% was observed at an addition level of 0.05%. Clove essential oil promoted the growth of lactic acid bacteria, but the effect did not significantly vary depending on its concentration. The count of Enterobacteriaceae in the 0.03% addition group was significantly lower than that in the control group. The total amount of biogenic amines decreased with increasing essential oil addition, and the inhibitory effect on putrescine and histamine was the highest. The 0.02% and 0.03% addition groups had the lowest N-nitrosamine content. The 0.03% addition group had the highest sensory score. Collectively, we concluded that that higher concentration of clove essential oil was more conducive to improving the quality and safety of dry fermented sausages. However, the addition of excess clove essential oil can mask the flavor. Therefore, it is considered appropriate to add 0.03% clove essential oil.

In order to explore the effects of different combinations of spice essential oils on the quality and safety of air-dried catfish sausages, sausages were prepared from marinated catfish surimi added with a 1:1 (m/m) blend of clove and star anise (CA), clove and perilla (CP), star anise and perilla (AP) or clove, star anise and perilla essential oil (CAP) at 0.03% or none as a control. Moisture content, water activity (a_w), pH, color difference, thiobarbituric acid reactive substance (TBARS) value, biological amine content, N-nitrosamine content, and microbial load were measured. Microbial community structure was analyzed by 16S rDNA high-throughput sequencing. The results showed that the moisture content of the AP group was 27.13%, and the a_w value was 0.765. The L^* and a^* values of the CA group were high, indicating typical characteristics of air-dried sausages. The pH of the four treatment groups was higher than that of the control group, and followed the descending order of CAP > AP > CA > CP. There was no significant difference in the inhibition of fat oxidation among different essential oil combinations (P > 0.05), but the TBARS value of air-dried sausages was significantly reduced by all combinations (P < 0.05). The contents of biogenic amine and N-nitrosamine in the AP group were low. The total number of bacteria, and the number of Enterobacteriaceae and Aeromonas were significantly lower in the AP group than in the control group (P < 0.05). High-throughput sequencing results showed low species richness in the AP and CAP groups and low relative abundance of pathogenic bacteria in the AP group. Overall analysis showed that AP was superior to the other groups in improving the quality and safety of air-dried catfish sausages.