Discrimination of the geographic origin of pork using multi-isotopes and statistical analysis

While global pork production has grown exponentially in recent decades to 109 Mt in 2010, methods aimed at verifying the geographic origin of pork products have yet to be thoroughly investigated. Here, we analyzed pork samples available in South Korea in order to discriminate their geographic origin.

A total of the 37 pork samples originated from South Korea and other countries (Denmark, Germany, France, Spain, Canada and Mexico) were collected in order to classify their geographic origins using multi-isotope ratios, such as δ¹⁸ O, δ² H, δ¹³ C, δ¹⁵ N values measured by IRMS, ⁸⁷ Sr/⁸⁶ Sr ratios measured by MC-ICP-MS, and multivariate statistical approaches.

There is a wide range of ⁸⁷ Sr/⁸⁶ Sr ratios in the pork samples, varying from 0.70779 to 0.71245, due to the lithology where the pork was raised. Canadian samples displayed the lowest δ¹⁸ O and δ² H values mainly due to the latitude effect. Furthermore, the δ¹³ C values of European and Canadian samples were lower than those of Korean and Mexican samples, depending on whether the feed was composed of either C₃ or C₄ plants. The δ¹⁵ N values of the European and Canadian samples were much higher than those of the other samples, possibly resulting from the δ¹⁵ N values of the feed.

While differences in pork samples were observed that depended on geographic origin, this study suggests that more detailed investigations are needed to validate whether a combination of multi-isotope and multivariate statistical approaches is a valid method for determining the geographic origin of pork.