Analysis Of Spoilage Ability Of Spoilage Bacteria Stored From Chilly Stored Fishes

China is the biggest producer of aquatic products, and farming output is exceeded amount of fishing all over the world. Cultured freshwater fish and marine culture fish is the important aquatic economy. With the improvement level of people,s life, Consumer have a slashing requirement to aquatic products freshness and taste. However, the limit to circulation of living fish, it has important significance for development of fresh fish cooling chain process, which is a effective solution to farmed fish deeply depend on living fish circulation. Microbial action is the principal fact to spoilage. Increasing study of spoilage bacteria is crucial to optimize to the fresh fish cooling chain process.In the paper, sensory quality, metabolic products of spoilage bacteria, (TVBN(Total Volatile Base Nitrogen)and TMA(Trimethylamine)), change of spoilage bacteria, the growth kinetic parameters of the spoilage bacteria and the yield factor of microbial metabolites(Y_TVBN/CFU and Y_TMA/CFU) were assayed and compared for sterile Pseudosciaena crocea tissue blocks and sterilized fish juice inoculated spoilage bacteria during storage. Spoilage ability of two specific spoilage bacteria Shewanella putrefaciens, Pseudomonas spp. and mixing of the two spoilage bacteria were analyzed from Pseudosciaena crocea stored aerobically at chilled. Spoilage ability of two dominant spoilage bacteria Shewanella putrefaciens and Pseudomonas spp. from two marine fish Pseudosciaena crocea and Scophthalmus maximus stored aerobically at chilled were studied. Furthermore, Spoilage ability of two dominant spoilage bacteria Pseudomonas spp. and Shewanella putrefaciens from Oreochromis niloticus and Pseudosciaena crocea stored aerobically at chilled was analyzed. And compared with spoilage ability of two dominant spoilage bacteria Shewanella putrefaciens and Pseudomonas spp. from marine fish Pseudosciaena crocea stored aerobically at chilled. The flowing results were:(1) Shelf life were 162h and 132h for sterile tissue blocks and sterilized fish juice inoculated with Shewanella putrefaciens, at this time TVBN were 31.74mg/100g and 29.64mg/100mL, TMA were 8.94mg/100g and 0.99mg/100mL, counts of Shewanella putrefaciens were 8.71 lg(CFU/g) and 8.56 lg(CFU/mL), Y_TVBN/CFU were 4.49×10^-8mg TVBN/CFU and 7.22×10^-8mL TVBN/CFU, Y_TMA/CFU were 1.74×10^-8mg TMA/CFU and 3.06×10^-9mL TMA/CFU. TMA was not a reliable physicochemical index for fish juice inoculated with spoilage bacteria. However TVBN could be used as a physicochemical index for fish juice. The relative error of the yield factor Y_TVBN/CFU for sterile fish blocks and sterilized fish juice was 37.81%. Therefore sterilized fish juice, which was used as a determination method of spoilage ability of spoilage bacteria, had certain reliability.(2) Shelf life was 162 h, 174 h, and 168 h, respectively for sterile tissue blocks inoculated with Shewanella putrefaciens, Pseudomonas spp. and compound bacteria, while relatively longer with Pseudomonas spp.. The value of Y_TVBN/CFU for Shewanella putrefaciens, Pseudomonas spp. and mixed bacteria was basically consistent, meanwhile the value of Y_TMA/CFU for Shewanella putrefaciens was higher than Pseudomonas spp. and mixed bacteria. The spoilage ability of Shewanella putrefaciens was more significant than Pseudomonas spp. and mixed bacteria. Pseudomonas spp. had inhibitory to the growth of Shewanella putrefaciens to some extent. However it had significant inhibitory when it reached high counts.(3) Shelf life was 162 h and 174 h respectively for sterile Pseudosciaena crocea tissue blocks inoculated with Shewanella putrefaciens and Pseudomonas fluorescens, at the point of shelf life, TVBN were 31.74mg/100g and 39.01mg/100mg, counts of Shewanella putrefaciens and Pseudomonas fluorescens were 8.71 lg(CFU/g) and 8.91 lg(CFU/g), Y_TVBN/CFU were 4.49×10^-8mg TVBN/CFU and 3.72×10^-8mg TVBN/CFU. The shelf life was 60 h and 72 h respectively for sterile Scophthalmus maximus tissue blocks inoculated with Shewanella putrefaciens and Pseudomonas putida, at this time TVBN were 35.48mg/100g and 37.56mg/100mg, counts of Shewanella putrefaciens and Pseudomonas putida were 8.14 lg(CFU/g) and 8.32 lg(CFU/g), Y_TVBN/CFU were 1.86×10^-7mg TVBN/CFU and 1.35×10^-7mg TVBN/CFU. The shelf life of sterile Pseudosciaena crocea tissue blocks was obvious longer than Scophthalmus maximus and the shelf life of the two fish blocks inculcated with Pseudomonas spp. was longer than Shewanella. Spoilage ability of two dominant spoilage bacteria Shewanella and Pseudomonas spp. from two marine fish stored aerobically at chilled were strong.(4) Shelf life was 132 h and 144 h respectively for sterile Oreochromis niloticus tissue blocks inoculated with Shewanella putrefaciens and Pseudomonas fluorescens , at the same time, TVBN were 23.46mg/100g and 24.30mg/100g, counts of Pseudomonas spp. and Shewanella putrefaciens were 8.83 lg(CFU/g) and 9.12 lg(CFU/g), Y_TVBN/CFU were 1.67×10^-8 mg TVBN/CFU and 9.10×10^-9 mg TVBN/CFU. The shelf life was 132 h and 162 h respectively for sterile Cyprinus carpio tissue blocks inoculated with Shewanella putrefaciens and Pseudomonas putida, at this time, TVBN were 27.12mg/100g and 22.51mg/100g, counts of Shewanella putrefaciens and Pseudomonas putida were 8.96 lg(CFU/g) and 9.07 lg(CFU/g), Y_TVBN/CFU were 9.28×10^-9mg TVBN/CFU and 1.81×10^-8mg TVBN/CFU. According to change of bacterial flora and the role of spoilage bacteria during chilled stored of the two cultured fishes. According to the change of microflora and the role during chilled stored. It could be preliminarily obtained that special spoilage organism of chilled Oreochromis niloticus and Cyprinus carpio was Pseudomonas spp. and Shewanella putrefaciens was special spoilage organism of Pseudosciaena crocea. Spoilage ability of the two dominant spoilage bacteria Shewanella putrefaciens and Pseudomonas spp. was strong.