Research On The Zhoushan Cephalopod Market Using DNA Barcode Technology

With the increase in the trade volume of cephalopods and the diversification of processing methods,commercial frauds related to fresh cephalopods and their processed products are also increasing.Some are caused by unintentional misclassification by merchants,but there are also low-value species.Acts of impersonating high-value species,these fraudulent acts not only damage the legitimate rights and interests of consumers,but food safety issues may even occur if they are not restrained.Therefore,grasping the current situation of the entire cephalopod market in Zhoushan and standardizing the market order are of great significance to the healthy development of Zhoushan cephalopod industry.With the increasing attention to food safety issues and the development of modern molecular biology technology,DNA-based molecular biology methods are playing an increasingly important role in identifying the authenticity of food labels.This study takes the cephalopod products in the Zhoushan market as the research object,grasps the current labeling status of the Zhoushan cephalopod market,and establishes two common cephalopods in food based on the fluorescence PCR method and the melting curve analysis method.The rapid detection of species(Illex argentinus and Todarodes pacificus)provides technical support for the detection of adulteration of cephalopod products on the market.The specific research results are as follows:(1)Zhoushan fresh cephalopod market research: complete preli minary species identification based on DNAbarcode technology,establish tree diagrams through phylogenetic analysis and compare with reference sequences to further complete species identification with precision to species,and verify the results of DNAbarcode comparison.The results showed that 41 of 42 samples from the market completed species identification,they were assigned to 11 families in 4 orders of cephalopods,and 5 of them were adulterated.(2)Zhoushan cephalopod processed product market research: The cephalopod processed product samples collected in the Zhoushan market have undergone processing methods including shredded,pickled,seasoned,roasted,and dried,and the species level has been identified.The results showed that 39 of 42 samples from the market completed species identification,they were assigned to 7 families in 4 orders of cephalopods,and one sample was found to be adulterated with low-value varieties instead of high-value varieties.behavior.The analysis results indicate that there is a certain degree of connection between the raw material species used in squid processed products and the product category,which DNA provides support for the establishment of relevant standards and regulations.(3)Based on SYBR Green's real-time PCR melting curve detection method,for the study of identifying two cephalopod species: firstly,specific primer pairs for the two target species are designed,and then through comparison with other 22 control species The amplification results verified the specificity of the primers,and finally the specificity of the primers was further verified by the melting curve method,and the Tm value of the melting peak of I.argentinus was 80.8? and the Tm value of the melting peak of T.pacificus was83.1?,Established a rapid identification method for two cephalopod products.