Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IMT Mines Ales, IPREM, Pau, France; Institut des sciences analytiques et de Physicochimie pour l'environnement et les Matériaux, UMR5254, Hélioparc, 2 avenue du Président Angot, 64053, Pau cedex 9, France.
Advanced Isotopic Analysis (A.I.A.), Hélioparc, 2 avenue du Président Angot, 64000, Pau, France.
Food Chem. 2023 Oct 15;423:136271. doi: 10.1016/j.foodchem.2023.136271. Epub 2023 May 5.
High value food products are subject to adulterations and frauds. This study aimed to combine, in our knowledge for the first time, inorganic chemical tracers (multi-elements and Sr isotopy) with volatile organic compound (VOCs) to discriminate the geographic origin, the varieties and transformation processes to authenticate 26 tea samples. By measuring Sr isotope ratio using the multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), 6 out of 11 regions were successfully discriminated. The combination with the ICP-MS inorganic pattern allowed to discriminate 4 more regions with a significance level of 0.05. VOCs fingerprints, obtained with selected ion flow tube mass spectrometer (SIFT-MS), were not correlated with origin but with the cultivar and transformation processes. Green, oolong, and dark teas were clearly differentiated, with hexanal and hexanol contributing to the discrimination of oxidation levels. With this multi-instrumental approach, it is possible to certify the geographical origin and the tea conformity.
高价值食品容易受到掺假和欺诈。本研究旨在首次结合无机化学示踪剂（多元素和 Sr 同位素）和挥发性有机化合物（VOCs），以鉴别地理来源、品种和转化过程，从而对 26 个茶叶样本进行真伪鉴别。通过使用多接收电感耦合等离子体质谱仪（MC-ICP-MS）测量 Sr 同位素比值，成功区分了 11 个地区中的 6 个。与 ICP-MS 无机图谱相结合，可以以 0.05 的显著性水平区分出另外 4 个地区。使用选择离子流管质谱仪（SIFT-MS）获得的 VOCs 指纹图谱与产地无关，而是与品种和转化过程有关。绿茶、乌龙茶和黑茶可以明显区分开来，其中己醛和己醇有助于区分氧化程度。通过这种多仪器方法，可以对产地和茶叶的一致性进行认证。
