Zacometti Carmela, Massaro Andrea, di Gioia Tommaso, Lefevre Stephane, Frégière-Salomon Aline, Lafeuille Jean-Louis, Fiordaliso Candalino Ingrid, Suman Michele, Piro Roberto, Tata Alessandra
Laboratorio di Chimica Sperimentale, Istituto Zooprofilattico Sperimentale delle Venezie, Vicenza, Italy.
Food Integrity Laboratory, Global Quality and Food Safety Center of Excellence, McCormick & Co., Inc., Carpentras, France.
J Mass Spectrom. 2023 Oct;58(10):e4953. doi: 10.1002/jms.4953. Epub 2023 Jul 3.
Thermal desorption direct analysis in real-time high-resolution mass spectrometry (TD-DART-HRMS) approaches have gained popularity for fast screening of a variety of samples. With rapid volatilization of the sample at increasing temperatures outside the mass spectrometer, this technique can provide a direct readout of the sample content with no sample preparation. In this study, TD-DART-HRMS's utility for establishing spice authenticity was examined. To this aim, we directly analyzed authentic (typical) and adulterated (atypical) samples of ground black pepper and dried oregano in positive and negative ion modes. We analyzed a set of authentic ground black pepper samples (n = 14) originating from Brazil, Sri Lanka, Madagascar, Ecuador, Vietnam, Costa Rica, Indonesia, Cambodia, and adulterated samples (n = 25) consisting of mixtures of ground black pepper with this spice's nonfunctional by-products (pinheads or spent) or with different exogenous materials (olive kernel, green lentils, black mustard seeds, red beans, gypsum plaster, garlic, papaya seeds, chili, green aniseed, or coriander seeds). TD-DART-HRMS facilitated the capture of informative fingerprinting of authentic dried oregano (n = 12) originating from Albania, Turkey, and Italy and those spiked (n = 12) with increasing percentages of olive leaves, sumac, strawberry tree leaves, myrtle, and rock rose. A predictive LASSO classifier was built, after merging by low-level data fusion, the positive and negative datasets for ground black pepper. Fusing multimodal data allowed retrieval of more comprehensive information from both datasets. The resultant classifier achieved on the withheld test set accuracy, sensitivity, and specificity of 100%, 75%, and 90%, respectively. On the contrary, the sole TD-(+)DART-HRMS spectra of the oregano samples allowed construction of a LASSO classifier that predicted the adulteration of the oregano with excellent statistical indicators. This classifier achieved, on the withheld test set, 100% each for accuracy, sensitivity, and specificity.
热脱附实时直接分析高分辨率质谱（TD-DART-HRMS）方法在快速筛查各种样品方面越来越受欢迎。随着样品在质谱仪外部温度升高时快速挥发，该技术无需样品制备即可直接读出样品成分。在本研究中，考察了TD-DART-HRMS在确定香料真实性方面的效用。为此，我们以正离子和负离子模式直接分析了磨碎黑胡椒和干牛至的正品（典型）和掺假（非典型）样品。我们分析了一组来自巴西、斯里兰卡、马达加斯加、厄瓜多尔、越南、哥斯达黎加、印度尼西亚、柬埔寨的正品磨碎黑胡椒样品（n = 14），以及掺假样品（n = 25），这些掺假样品由磨碎黑胡椒与该香料的无功能副产品（胡椒粒头或用过的胡椒）或与不同外源物质（橄榄核、绿扁豆、黑芥子、红豆、石膏、大蒜、木瓜籽、辣椒、绿茴芹或芫荽籽）的混合物组成。TD-DART-HRMS有助于获取来自阿尔巴尼亚、土耳其和意大利的正品干牛至（n = 12）以及添加了不同比例橄榄叶、漆树、草莓树叶子、桃金娘和岩蔷薇的样品（n = 12）的信息丰富的指纹图谱。在通过低水平数据融合合并磨碎黑胡椒的正、负数据集后，构建了一个预测性套索分类器。融合多模态数据能够从两个数据集中检索到更全面的信息。所得分类器在保留测试集上的准确率、灵敏度和特异性分别达到100%、75%和90%。相反，牛至样品的单独TD-(+)DART-HRMS光谱能够构建一个套索分类器，该分类器以出色的统计指标预测牛至的掺假情况。该分类器在保留测试集上的准确率、灵敏度和特异性均达到100%。
