Abstract:In this work, changes in the quality and storage life of sturgeon fillets were compared during 3℃ partial freezing storage and 4℃ storage in order to develop a method that will improve the storage quality of sturgeon fillets. Several indicators including sensory evaluation, total visible colonies (TVC), pH value, volatile base nitrogen value (TVB-N), thiobarbituric acid (TBA), texture, volatile substances, moisture distribution state, and microstructure changes of muscle fibers were studied and were later used to evaluate the effect of two temperature storages on the quality of sturgeon fillets. The results showed that the proportion of free water and combined water, TVB-N, TBA, and TVC of sturgeon fillets stored at 4℃ and 3℃ increased with the extension of storage time, whereas texture indices such as hardness and springiness and the score of sensory evaluation showed a decreasing trend. Microstructure observations illustrated that stickiness appeared between the muscle fibers, and the sarcomere gradually became blurred with the extension of storage time, especially during the later period of 3℃ partial freezing storage. Interestingly, its chemical indicators including TVB-N and TBA did not exceed the hygienic limits, whereas sensory evaluation rates were unacceptable. Taking all these indicators into consideration, it was observed that the storage life of sturgeon fillet was 6 days at 4℃ and 18 days at 3℃. It can therefore be concluded that partial freezing temperature storage (3℃) maintained the quality of sturgeon fillets much longer compared with storage at 4℃. Microbes have a small effect on the decay process of sturgeon fillets, whereas ice crystal formation and endogenous cathepsin may be the main influencing factors that led to the destruction of its structure during 3℃ partial freezing storage. Results of this study will enrich the basic theory of aquatic products and provide a technique for sturgeon fillets storage.
