Technological Study Of Isotope And Mineral Element Finegerprint For Cattle Geographical Origin Traceability

The analysis of stable isotope ratio and mineral element content is one of effective methods for food geographical origin traceability. The objective of this article was to probe into the feasibility and validity using the analysis of isotope and minernal element fingerprint for cattle geographical origin traceability. Theδ¹³C andδ¹⁵N values of cattle tissues and feeds were determined using isotope ratio mass spectrometry (IRMS), the 8D values of cattle tail hair were determined using continuous flow-isotope ratio mass spectrometry (CF-IRMS), the ratio of ²⁰⁶Pb/²⁰⁷Pb, ²⁰⁸Pb/²⁰⁷Pb and the content of Na,Mg,Al,K,Ca,V,Mn,Fe,Co,Ni,Cu,Zn,Ga,As,Se,Sr,Zr,Mo,Sn,Sb,Ba,Pb were determined using the inductively coupled plasma mass spectrometry (1CP-MS), and the ratio of ⁸⁷Sr/⁸⁶Sr were determined using the thermal ionization mass spectrometry (TIMS). Then the data were performed using multivariate analysis including ANOVA, principal component analysis (PCA), cluster analysis (CA), linear discrimant analysis (LDA) with the help of SAS and DPS package for windows. The research were mainly focused on different analysis of stable isotope ratio and mineral element content of cattle from different regions, correlation analysis of carbon and nitrogen isotopic composion between de-fatted beef, crude fat and cattle tail hair, discrimant analysis using stable isotope ratios and mineral contents for cattle geographical origin assessment, and the relationship between stable isotope ratios, mineral contents of cattle tissues and their breeding environment.In addition, the model experiment for cattle geographical origin traceability using stable isotope analysis was designed because of the difficulties in beef samples taking, higher cost, and the probability of using cattle tail hair instead of beef in the study of cattle traceability. The difference ofδ¹³C,δ¹⁵N values among muscle from foreside, central section, rump of cattle and cattle organs including heart, liver and lung were compared. The changing trends ofδ¹³C,δ¹⁵N values in different segment of cattle tail hair with the change of feeds composition were analyzed, and the correlationship between cattle tail hair, muscle, and feeds were studied to probe into the feasibility of tracing the cattle geographical origin and their feeding history using cattle tail hair instead of muscle.The results showed that there were very significant differences according to region in the mean values of carbon, nitrogen, lead, hydrogen isotope ratios and minernal element content in the cattle tissues. The fingerprint of these indicators in cattle tissues from the different regions was unique. A significant correlationship was found in carbon and nitrogen isotope ratios between de-fatted beef, crude fat and cattle tail hair. The results of discrimant ananlysis were consistent using these indicators, which indicated that all of them could be used for cattle geographical origin treaceablity. The order of isotopic indicators wereδ¹³C>δD>²⁰⁶Pb/²⁰⁷Pb>δ¹⁵N>²⁰⁸Pb/²⁰⁷Pb and ⁸⁷Sr/⁸⁶Sr according to the rate of correct classification from high to low for cattle geographical origin, and the order of mineral element were Se>Sr>Fe>Ni>Zn according to the rate of correct clissification. Furthermore, the rate of correct classification could be improved by combination of these indicators. The model experiment showed that there was no significant difference inδ¹³C andδ¹⁵N values between muscles from different position and different organs, i.e. theδ¹³C andδ¹⁵N values of cattle tissues was not affected by sample from different position. The feeds, especially the staple feeds, had more effect on theδ¹³C andδ¹⁵N values of cattle tissues, while the variety and individual had less effect on them. The variety and individual had more effect onδ¹⁵N thanδ¹³C. Theδ¹³C value in cattle tissues was very good in classifying the beef coming from the different regions where cattle feeds were significantly different in the proportion of C₄ and C3. Theδ¹⁵N value was good to distinguish the cattle from the farm land and the pasture. The 8D in cattle tissues was closely related to the geographical conditions and was decreasing as the latitude was increasing. De-fatted beef and cattle tail hair enriched in ¹³C to their feeds in the proportion of 3%o, and enriched in ¹⁵N in the proportion of 3‰- 5‰, plus, cattle variety and individual had effect on the proportion of enrichment. Cattle tail hair enriched in ¹³C much more than de-fatted beef, but less than de-fatted beef in ¹⁵N, while fat tissue depleted in ¹³C relative to feeds. Though a significant correlation was found between cattle tail hair, de-fatted beef and crude fat, there was a different correlation between cattle tail hair of different segment and muscle in carbon and nitrogen isotope ratio. The results showed that theδ¹³C andδ¹⁵N values of cattle tail hair in the segment which distance from root (0-3cm) was highly correlated with that of the muscle.The above results showed that the technique of isotope and mineral element fingerprint was an effective method for cattle geographical origin traceability, and was feasible to trace the cattle geographical origin and their feeding histoty using cattle tail hair.