Comprehensive Evaluation On Freshness And Establishment Of The Shelf-life Model Of Salmon

Salmon was taken as the research object in this paper, and the freshness indexes were measured in the process of storage. And the physical and chemical indicators and microbial indicators were non-linear fitted through shelf-life primary model and the secondary model. And as a result, the shelf-life models were established. The above and experimental researches offered a theoretical basis for salmon preservation in different refrigerated temperatures. The main results obtained in this study were as follows:1. The TVB-N value, TBA value, K value, trimethylamine value and standard plate count value of salmon slices stored at 0 increase℃ d with the extension of storage time. The total color difference value first increased then decreased. Sensory evaluation score had been showed a trendency of decrease. Electronic nose could distinguish salmon slices under different storage periods, consistenting with the conclusion of physical and chemical indicators.2. The changes of bacterias in salmon slices at the different storage temperatures were studied, and microbial growth was non-liner fitted by using the first-order chemical reaction kinetics model, the modified Gompetz model, Baranyi and Roberts model were used as the primary microorganism growth dynamics model respectively. The results showed that the remaining shelf-life model obtained by Belehradek equation was more accurately than that of Arrhenius equation for salmon slices. The relative-error of the established shelf-life model was within the scope of(±18.90%), which suggested that the bacteria of salmon slices during cold storage could be described well by the relative shelf-life prediction models.3. Fresh salmon was stored in different refrigerated temperatures, its TVB-N, SPC, color difference, TBA and sensory evaluation value were measured. And the results of sensory evaluation and physicochemical indicators were applied to the primary and secondary quality growth dynamics model. Results showed that the shelf-life models were validated with quality indicators, and the relative error of predicted value and actual value was less than or equal to(±20%). This model could well predict the shelf-life of salmon slices stored at refrigerated temperatures.4. The sterile salmon fillets and juice which were inoculated with Pseudomonas fluorescent were taken as the research objects, and the number of spoilage bacteria, corruption metabolites and the change of sensory evaluation were measured during the cold storage. The yield factor(YTVB-N/CFU) for production of TVB-N was used as the quantitative index of spoilage ability when produced terrible odour, in order to measure the spoilage ability of specific spoilage organism of salmon fillets. The results showed that: the shelf-life of sterile salmon fillets and juice which were inoculated with Pseudomonas fluorescent were 216 h and 144 h, and the Pseudomonas fluorescent had a strong corruption ability, This research could be aimed to restrain the growth of the specific spoilage organisms for salmon and the shelf-life could be prolonged to provide certain reference for salmon slices.