Analysis On The Quality Changes Of Dried Red Fish During Processing And Storage And The Potential Hazards Of Fusarium Isolates

Dried red fish is a kind of dried aquatic products with characteristic flavor in the coastal areas of southern China,which has the characteristics of low fat and high protein.The traditional processing techniques of dried red fish are pickled and sun-dried.The salt content of fresh red fish after pickling is lower than that of other pickled fish products,the taste of fish is better and the edible value is higher.In the process of processing and storage,dried red fish is easily affected by processing conditions,storage temperature,humidity and other storage conditions,and the basic nutrients are easy to change or even deteriorate,which will lead to the decline of its edible value.The fat and protein of dried red fish are easy to be oxidized and degraded during processing and storage.Due to the production of Fusarium growth stress factors by protein decomposition and the humid and muggy weather in the southern coastal areas,dried fish are prone to mildew during processing and storage.Through the previous research and investigation of the research group,the pollution rate of dried fish by Fusarium oxysporum was high.T-2,as one of the most toxic secondary metabolites of Fusarium oxysporum,which poses a serious threat to human and animal health.T-2 is one of the mycotoxins with strong toxicity and common pollution at present,which can cause varying degrees of damage to the immune system,liver system,digestive system and reproductive system of the body.Therefore,the study determined the basic nutritional composition,quality deterioration index,amino acid content and protein characteristics of dried red fish during processing and storage.To provide theoretical basis and reference for the processing and preservation conditions of dried aquatic products.At the same time,by simulating the process of T-2 produced by Fusarium oxysporum in dried fish,the fermentation broth producing T-2was intragastrically administered to mice for 7 days to analyze its potential toxicity to mice,so as to provide a new theoretical basis for the toxic mechani.In this study,the water content,total ash content,crude protein content,crude fat content,p H value,thiobarbituric acid reactant(TBA)content,volatile base nitrogen(TVB-N)content,non-protein nitrogen content,amino acid content and protein component content of dried red fish during pickling,sun-drying and storage were determined to analyze the quality changes,nutrition score and deterioration during processing and storage.After intragastric administration of T-2 fermentation broth from dried fish culture medium for 7 days,the blood indexes of mice were determined by automatic hematology analyzer,and the liver enzyme activity of mice was determined by automatic enzyme labeling instrument according to the operation method of kit.The micronucleus rate of bone marrow and the rate of sperm deformity in mice were observed and counted under microscope to explore the immunotoxicity,hepatotoxicity and genotoxicity of T-2 produced by Fusarium oxysporum isolated from red fish.sm of T-2 toxin.The main results are as follows:(1)During the processing and storage of dried red fish,with the extension of time,the water content of dried red fish decreased,and the total ash content increased at first and then decreased.The content of crude protein increased with the increase of time,and fat oxidation occurred in the pickled dried red fish at the initial stage.During the storage period,the TBA value,TVB-N value and non-protein nitrogen content of dried red fish increased or decreased with the extension of storage time,resulting in the deterioration of the quality of dried red fish.(2)During the storage period of dried red fish,the total amino acids did not change significantly,the ratio of EAA/NEAA was in the range of 0.6 to 0.68,and the ratio of flavor amino acids to total amino acids was about 0.53.From the point of view of nutrition,RC is about 1.00 and SRC is in the range of 94.41 to 98.89.The results showed that the dried red fish had higher nutrition during the storage period.(3)The contents of different soluble proteins in dried red fish during storage are as follows: insoluble protein content > water-soluble protein content > salt-soluble protein content.With the increase of storage time,the color of each soluble protein band will fade or disappear,indicating that each soluble protein has been degraded during the storage period.(4)The fermentation broth of T-2 produced in dried fish culture medium could significantly decrease the number of platelet(PLT)in mice(P< 0.05).Erythrocyte(RBC),leukocyte(WBC),alkaline phosphatase(AKP)activity,acid phosphatase(ACP)activity,bone marrow micronucleus rate and sperm deformity rate increased significantly,indicating that Fusarium oxysporum fermentation broth producing T-2 in dried fish culture medium has strong immunotoxicity,hepatotoxicity and genotoxicity in mice.