(1.广东海洋大学 食品科技学院/广东省水产品加工与安全重点实验室/广东省海洋生物制品工程实验室/ 水产品深加工广东普通高等学校重点实验室, 广东 湛江 524088;2.大连工业大学 海洋食品精深加工关键技术省部共建协同创新中心, 辽宁 大连 116034)
(1.College of Food Science and Technology, Guangdong Ocean University/Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety/Guangdong Province Engineering Laboratory for Marine Biological Products/Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, Zhanjiang 524088, China;2.Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China)
To study the effects of temperature fluctuation on the freshness and quality of cold fresh cultured Trachinotus ovatus, the temperature conditions during cold chain circulation were simulated, and the variation trends of total number of colonies and cryophilic bacteria, pH value, TVB-N value, TBA value, and K value during sample circulation were analyzed, and the microbial community succession was tested by high-throughput sequencing technology. The results showed that with the extension of circulation time, the total number of colonies and cryophilic bacteria in fish meat increased, accompanied by the deterioration of freshness indexes, in which the quality deterioration rate of breaking chain group was significantly higher than that of cold chain group (P<0.05). There was a significant correlation between microbial indexes and freshness indexes (P<0.05), which could well reflect the freshness loss of cold fresh Trachinotus ovatus during the circulation process. Alpha diversity index and principal component analysis showed that the diversity and structure of microbial community in Trachinotus ovatus were affected by the fluctuation of ambient temperature. The analysis of the bacterial phase during the circulation of the samples showed that the main dominant bacteria at phylum level were Proteobacteria and Firmicutes. At genus level, Phenylobacterium was the main dominant bacteria. The secondary dominant bacteria in the cold chain group were Sphingomonas, Longilinea and unclassified_Anaerolineaceae. The secondary dominant bacteria in breaking chain group were Sporosarcina, Longilinea and unclassified_Anaerolineaceae. From the microbial metabolism perspective, it was found that the relative abundance of genes involved in metabolism in breaking chain group during refrigeration was higher than that in the cold chain group at the same time. The research results reflected the potential quality and safety risks of Trachinotus ovatus due to temperature fluctuation during cold chain circulation. At the same time, it was hoped to provide a reference for the development of targeted Trachinotus ovatus preservation technology and the construction of cold chain logistics from the microbial perspective.