Process optimization and quality analysis of Siniperca chuatsi fermentation based on mixed bacteria fermentation

In order to explore the technology of artificial inoculation with mixed bacteria fermention for mandarin fish (Siniperca chuatsi), to improve the extensive and empirical processing mode and to ameliorate the quality of traditional fermented S. chuatsi, we optimized the fermentation process conditions (fermentation temperature, fermentation time, strain ratio and starter inoculation amount) inocuted with mixture starter by single factor and response surface tests. Then we determined the moisture, pH, amino nitrogen, total acid, thiobarbituric acid reactive value (TBARS) and total volatile base nitrogen (TVB-N) content and compared them with traditional natural fermented fish, so as to investigate the effect of inoculation fermentation on its quality. The optimal fermentation process for S . chuatsi was obtained (mass ratio of Pediococcus pentosaceu∶Lactobacillus sakei∶Staphylococcus carnosus of 1∶1∶3; inoculum of 1.0%; fermentation temperature of 22 ℃; fermentation time of 4 d). Compared with naturally fermented S. chuatsi, the mass fractions of moisture and pH of the inoculated mixed starter fermented fish decreased by 2.04% and 0.46%, respectively. In a shorter fermentation time, its mass fraction of amino nitrogen was similar with that of naturally fermented fish, and the mass fraction of total acid increased by 29.27%. The mass fractions of TBARS and TVB-N decreased by 35.00% and 53.10%, respectively. In conclusion, the inoculated mixed starter culture fermentation of S. chuatsi helps to improve its quality and safety, shorten the fermentation time, and control the fermentation process.