Bojolly Daline, Doyen Périne, Le Fur Bruno, Christaki Urania, Verrez-Bagnis Véronique, Grard Thierry
Université Littoral Côte d'Opale , EA 7394 - ICV - Institut Charles Viollette, USC Anses - ULCO, F-62200 Boulogne-sur-Mer, France.
Laboratoire d'Océanologie et de Géosciences, UMR 8187 (ULCO, Lille 1, CNRS) , 62930 Wimereux, France.
J Agric Food Chem. 2017 Feb 1;65(4):913-920. doi: 10.1021/acs.jafc.6b04713. Epub 2017 Jan 24.
Bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) are among the most widely used tuna species for canning purposes. Not only substitution but also mixing of tuna species is prohibited by the European regulation for canned tuna products. However, as juveniles of bigeye and yellowfin tunas are very difficult to distinguish, unintentional substitutions may occur during the canning process. In this study, two mitochondrial markers from NADH dehydrogenase subunit 2 and cytochrome c oxidase subunit II genes were used to identify bigeye tuna and yellowfin tuna, respectively, utilizing TaqMan qPCR methodology. Two different qPCR-based methods were developed to quantify the percentage of flesh of each species used for can processing. The first one was based on absolute quantification using standard curves realized with these two markers; the second one was founded on relative quantification with the universal 12S rRNA gene as the endogenous gene. On the basis of our results, we conclude that our methodology could be applied to authenticate these two closely related tuna species when used in a binary mix in tuna cans.
大眼金枪鱼（Thunnus obesus）和黄鳍金枪鱼（Thunnus albacares）是罐头加工中使用最广泛的金枪鱼品种。欧洲对金枪鱼罐头产品的规定不仅禁止品种替代，也禁止品种混合。然而，由于大眼金枪鱼和黄鳍金枪鱼的幼鱼很难区分，在罐头加工过程中可能会发生无意的替代。在本研究中，利用TaqMan qPCR方法，分别使用来自NADH脱氢酶亚基2和细胞色素c氧化酶亚基II基因的两个线粒体标记来鉴定大眼金枪鱼和黄鳍金枪鱼。开发了两种基于qPCR的不同方法来量化用于罐头加工的每种品种鱼肉的百分比。第一种方法基于使用这两个标记实现的标准曲线进行绝对定量；第二种方法基于以通用的12S rRNA基因作为内源性基因进行相对定量。根据我们的结果，我们得出结论，当在金枪鱼罐头中以二元混合物形式使用时，我们的方法可用于鉴定这两种亲缘关系密切的金枪鱼品种。
