Abstract: This study aimed to investigate the effects of a mixed starter culture of moderate halophilic bacteria and exogenous L-Lys on the fermentation quality of fish paste. After 60 d of mixed-culture fermentation with Halobacillus campisalis, Halobacillus faecis, Bacillus aquimaris and Bacillus hwajinpoensis, the pH, total acidity, amino nitrogen, volatile base nitrogen, free amino acid and volatile compounds were measured. Leiocassis longirostris meat was used as the fermentation substrate. Four groups were set up. Group 1 was added only 15% salt (control), group 2 was added with 15% salt and 0.1% L-Lys, group 3 was added with 15% salt and the mixed culture, and group 4 was added with 15% salt, 0.1% L-Lys and the mixed culture. The results demonstrated that the total acidity in groups 1–4 were 0.382 5%, 0.63%, 0.607 5% and 0.585%, respectively, suggesting a significant increase for the experimental groups relative to the control group (P < 0.05). On the other hand, there was no significant difference in amino nitrogen content between group 3 and the control (P > 0.05), while a significant increase was observed for groups 2 and 4 compared to the control group (P < 0.05). All three experimental groups exhibited a significant reduction in volatile base nitrogen content in comparison to the control group (P < 0.05). Moreover these groups contained higher amounts and more varieties of amino acids and were rich in volatile flavor compounds, and their sensory evaluation and flavor were better than the control.

Key words: moderate halophilic bacteria, mixed starter cultures, L-Lys, fish paste, quality