Abstract:
To effectively control quality and shelf life of fermented fish, strains, which can be used as starter culture, were separated and screened from traditional fermented
Trachinotus ovatus. Using catalase positive, salt tolerance, antibacterial properties and histamine-free as the valuation indexes, the target strains were isolated by dilution separation method, and strains biological characteristics, flavor and tastes of metabolites were evaluated. The experimental results showed that two potential fermented strains (zh-b and zh-f) were screened from 38 strains, which were isolated from the fermented
Trachinotus ovatus. According to molecular biological identification, two strains were
Pediococcus pentosaceus and
Lactobacillus plantaruma, and their most appropriate temperatures were 20 and 30 ℃, the optimal pH was 5 and 6, respectively. Both strains had antibacterial activity against
Staphylococcus aureus and
Escherichia coli, but the
Lactobacillus plantarum showed the better antibacterial activity, and the acid production capacity was far higher than that of
Pediococcus pentosaceus. Fermentation products were determined by electronic nose, it was and found that methyl groups, sulfides, nitrogen oxides, alcohols or aldehydes and ketones and organic aromatic sulfides produced by
Pediococcus pentosaceus (64.10, 57.98, 44.75, 40.22 and 19.93) were higher than those of
Lactobacillus plantarum (5.50, 34.11, 10.68, 0.00 and 8.95), which was a major contributor to aroma components. The electronic tongue test showed that both strains had the ability to produce umami and fresh aftertaste, and the taste values of
Pediococcus pentosaceus were 14.32 and 6.64, which were significantly higher than those of
Lactobacillus plantarum, which produced umami and fresh aftertaste (3.20 and 2.90), but only
Lactobacillus plantarum produced a sour taste. In addition, both strains also produced a very small amount of bitterness. The research would provide a basis for the large-scale production of fermented
Trachinotus ovatus using the two strains as a mixed starter.