Individual Recognition Of Jellfish And Sea Cucumber Based On The Analysis Of The Key Molecular Properties

Seafood traceability is important in guaranteeing the quality of the seafood. It also shows a great significance for standarding seafood market, protecting the interests of consumers and the local products.In this paper, Rhopilema esculentum Kishinouye and Stichopus japonicus were as the major raw materials, originated from Yingkou and Dalian, respectively. The key molecule for Rhopilema esculentum Kishinouye is DNA, the technique of PCR-RFLP was used to identification Rhopilema esculentum Kishinouye and Stomolophus meleagris. The key molecule for Stichopus japonicus is collagen, the technique of peptide fingerprint maps was adopted.As for Rhopilema esculentum Kishinouye, the genetic identification of Rhopilema esculentum Kishinouye and Stomolophus meleagris was based on PCR amplification of a common 700 bp fragment of the 16 S rRNA gene and followed digestion by 9 kinds restriction enzymes. The results showed that 5 kinds restriction enzymes(HindⅢ, HpaⅠ, XhoⅠ, DraⅠ, SspⅠ) identified Rhopilema esculentum Kishinouye and Stomolophus meleagris. Hind Ⅲ and HpaⅠhad one site in Stomolophus meleagris with products of 373 and 420 bp, respectively. Xho Ⅰ and Dra Ⅰ had one site in Rhopilema esculentum Kishinouye with products of 142 and 429 bp, respectively. SspⅠhad one site in Rhopilema esculentum Kishinouye and two sites in Stomolophus meleagris with products of 477 and 133/258 bp, respectively. Same results were found in pickled Rhopilema esculentum Kishinouye. The method was applied to authenticate 5 kinds commercial picked jellfish, and the results showed that two samples were Rhopilema esculentum Kishinouye, one was Stomolophus meleagris, and two were other species.As for sea cucumber, the fish skin gelatin extraction method was used to extract gelatin of sea cucumber and its properties were investigated. The results showed that the extraction of gelatin from sea cucumber was failed, which may be related to the extreme insolubility of collagen of sea cucumber. Based on the peptide fingerprint maps of pepsin-solubilized collagen(PSC) from sea cucumber body wall and fish skin, the results showed that V8 and α-chmotrypsin effectively distinguished them. These two enzymes were used to digest collagen in both north and south sea cucumber. But the results showed that both presented the same maps and were unable to identify. At the same time, the results of differential scanning calorimeter(DSC) shows that the denaturation temperature of collagen in south sea cucumber was slightly higher than the north, but had no significant differences between them.