Duarte Bernardo, Mamede Renato, Carreiras João, Duarte Irina A, Caçador Isabel, Reis-Santos Patrick, Vasconcelos Rita P, Gameiro Carla, Ré Pedro, Tanner Susanne E, Fonseca Vanessa F
MARE-Marine and Environmental Sciences Centre & ARNET-Aquatic Research Infrastructure Network Associated Laboratory, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Foods. 2022 Sep 4;11(17):2699. doi: 10.3390/foods11172699.
Provenance and traceability are crucial aspects of seafood safety, supporting managers and regulators, and allowing consumers to have clear information about the origin of the seafood products they consume. In the present study, we developed an innovative spectral approach based on total reflection X-ray fluorescence (TXRF) spectroscopy to identify the provenance of seafood and present a case study for five economically relevant marine species harvested in different areas of the Atlantic Portuguese coast: three bony fish-, , and ; one elasmobranch-; one cephalopod-. Applying a first-order Savitzky-Golay transformation to the TXRF spectra reduced the potential matrix physical effects on the light scattering of the X-ray beam while maintaining the spectral differences inherent to the chemical composition of the samples. Furthermore, a variable importance in projection partial least-squares discriminant analysis (VIP-PLS-DA), with k - 1 components (where k is the number of geographical origins of each seafood species), produced robust high-quality models of classification of samples according to their geographical origin, with several clusters well-evidenced in the dispersion plots of all species. Four of the five species displayed models with an overall classification above 80.0%, whereas the lowest classification accuracy for was 74.2%. Notably, about 10% of the spectral features that significantly contribute to class differentiation are shared among all species. The results obtained suggest that TXRF spectra can be used for traceability purposes in seafood species (from bony and cartilaginous fishes to cephalopods) and that the presented chemometric approach has an added value for coupling with classic TXRF spectral peak deconvolution and elemental quantification, allowing characterization of the geographical origin of samples, providing a highly accurate and informative dataset in terms of food safety.
溯源和可追溯性是海鲜安全的关键方面，有助于管理者和监管机构，并使消费者能够清楚了解他们所消费海鲜产品的来源。在本研究中，我们开发了一种基于全反射X射线荧光（TXRF）光谱的创新光谱方法来识别海鲜的来源，并针对在葡萄牙大西洋沿岸不同地区捕获的五种具有经济价值的海洋物种进行了案例研究：三种硬骨鱼——、和；一种软骨鱼——；一种头足类动物——。对TXRF光谱应用一阶Savitzky-Golay变换可减少潜在基质对X射线束光散射的物理影响，同时保持样品化学成分固有的光谱差异。此外，采用具有k - 1个成分的投影变量重要性偏最小二乘判别分析（VIP-PLS-DA，其中k是每种海鲜物种的地理来源数量），根据样品的地理来源生成了强大的高质量分类模型，在所有物种的散点图中都有几个聚类得到了充分证明。五个物种中有四个显示出总体分类高于80.0%的模型，而最低的分类准确率为74.2%。值得注意的是，所有物种中约10%对类别区分有显著贡献的光谱特征是共享的。所得结果表明，TXRF光谱可用于海鲜物种（从硬骨鱼和软骨鱼到头足类动物）的可追溯性目的，并且所提出的化学计量学方法对于与经典TXRF光谱峰去卷积和元素定量相结合具有附加价值，能够表征样品的地理来源，在食品安全方面提供高度准确且信息丰富的数据集。
