Study On The Screening Of Fingerprint Information For Geographical Origin Traceability Of Crassostrea Hongkongensis

Geographical origin traceability is an important part of food traceability system,which could ensure the food quality and security from source. Analyses of stable isotope ratio, inorganic element content were considered to be the effective techniques for food geographical origin traceability, and widely used in all kinds of food. The objective of this paper was to investigate the feasibility of these techniques for the geographical origin traceability of Crassostrea hongkongensis and choose the optimalizing indicators for geographical origin traceability. All of Crassostrea hongkongensis samples were collected from different geographical origins(Shantou, Huidong, Qinzhou, Zhuhai, Taishan,Yangjiang and Zhanjiang) in different seasons(January, April, July, October) in 2014. The values of δ13C、δ15N、δD、δ18O in whole tissues,δ13C、δ15N in de-fatted tissues and δ13C、δ15N in crude fat were measured by isotope ratio mass spectrometry(IRMS); Total 20 kinds of inorganic elements(Ag、As、Ba、Be、Cd、Co、Cr、Cu、Li、Mn、Mo、Ni、Pb、Rb、Sb、Se、Tl、U、V and Zn) in whole tissues were measured by inductively coupled plasma mass spectrometry(ICP-MS).Multiple comparison analysis, Principal component analysis( PCA), cluster analysia( CA) and discriminant analysis were utilised to screen the reliable parameters, including Crassostrea hongkongensis tissue, stable isotope indicators and inorganic element indicators.The selected indicators of experimental samples of Crassostrea hongkongensis in 2013 were employed to test the validity of this method. This work is to provide some reference to establish the discriminant model and geographical origin traceability database of Crassostrea hongkongensis preliminary.The main conclusions were as follows:(1) Stable isotope fingerprint technology and inorganic element fingerprint technology were basically feasible for checking the geographical provenance of Crassostrea hongkongensis.(2) The optimal traceability tissue was the whole Crassostrea hongkongensis, the combination of carbon and nitrogen were the most efficient stable isotope indexes.(3) The inorganic element factors of different seasons were as follows: the contents of Ag、As、Mo、U and Cu for winter; the contents of As、Li、Tl、Co、Se and Zn for spring;the contents of As、Li、Tl、Co、Se and Zn for summer; and the contents of Cu、Mn、Co、As、Ni、Mo and Cr for autumn.(4) The retrospective factors of different seasons established by the analysis of the combinatorial informations of stable isotope and inorganic element fingerprint were as follows: δ13C、δ15N 、Cu、Mo、Ag and U for analysis of winter samples; δ15N、Li、Tl、As、Co and Se for analysis of spring samples; the retrospective factors in summer wereδ13C、δ15N、Be、Mo、Rb、Zn and Cu; δ13C、δ15N and As、Co、Mn and Cu for autumn samples.(5) The combinatorial information of fingerprint could notablely improved the correct classification rate and stability of Crassostrea hongkongensis discriminant model, and had a better origin traceable effect than those single index.(6) Crassostrea hongkongensis collected in 2013 were as testing samples to verify the reliablity of screened traceable indicators, the percentage of correctly classified was 83.3%.(7) The geographical origin traceability technology of Crassostrea hongkongensis based on IRMS 、 ICP-MS and the combination of them was established preliminarily,which can be a reliable techinique to trace the geographical origin and to improve the security management system of Crassostrea hongkongensis.