MARE - Marine and Environmental Sciences Centre & ARNET - Aquatic Research Network Associated Laboratory, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.
Departamento de Biologia Vegetal da Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.
J Food Sci. 2023 Apr;88(4):1349-1364. doi: 10.1111/1750-3841.16492. Epub 2023 Feb 15.
The high demand and economic relevance of cephalopods make them prone to food fraud, including related to harvest location. Therefore, there is a growing need to develop tools to unequivocally confirm their capture location. Cephalopod beaks are nonedible, making this material ideal for traceability studies as it can also be removed without a loss of commodity economic value. Within this context, common octopus (Octopus vulgaris) specimens were captured in five fishing areas along the Portuguese coast. Untargeted multi-elemental total X-ray fluorescence analysis of the octopus beaks revealed a high abundance of Ca, Cl, K, Na, S, and P, concomitant with the keratin and calcium phosphate nature of the material. We tested a suite of discrimination models on both elemental and spectral data, where the elements contributing most to discriminate capture location were typically associated with diet (As), human-related pressures (Zn, Se, and Mn), or geological features (P, S, Mn, and Zn). Among the six different chemometrics approaches used to classify individuals to their capture location according to their beaks' element concentration, classification trees attained a classification accuracy of 76.7%, whilst reducing the number of explanatory variables for sample classification and highlighting variable importance for group discrimination. However, using X-ray spectral features of the octopus beaks further improved classification accuracy, with the highest classification of 87.3% found with partial least-squares discriminant analysis. Ultimately, element and spectral analyses of nonedible structures such as octopus beaks can provide an important, complementary, and easily accessible means to support seafood provenance and traceability, whilst integrating anthropogenic and/or geological gradients.
头足类动物的高需求和经济相关性使其容易成为食品欺诈的目标，包括与收获地点有关的欺诈。因此，迫切需要开发工具来明确确认其捕捞地点。头足类动物的喙不可食用，这使得该材料非常适合可追溯性研究，因为它可以在不损失商品经济价值的情况下被去除。在此背景下，在葡萄牙沿海的五个捕鱼区捕获了普通章鱼（Octopus vulgaris）标本。对头足类动物喙的非靶向多元素全 X 射线荧光分析显示，Ca、Cl、K、Na、S 和 P 的丰度很高，与该材料的角蛋白和磷酸钙性质一致。我们在元素和光谱数据上测试了一系列鉴别模型，对鉴别捕捞地点最有贡献的元素通常与饮食（As）、与人类相关的压力（Zn、Se 和 Mn）或地质特征（P、S、Mn 和 Zn）有关。在根据喙中元素浓度将个体分类到其捕捞地点的六种不同化学计量学方法中，分类树达到了 76.7%的分类准确性，同时减少了用于样品分类的解释变量数量，并突出了用于组间区分的变量重要性。然而，使用章鱼喙的 X 射线光谱特征进一步提高了分类准确性，偏最小二乘判别分析发现的最高分类准确率为 87.3%。最终，不可食用结构（如章鱼喙）的元素和光谱分析可以为支持海鲜产地和可追溯性提供重要的、互补的和易于获取的手段，同时整合人为和/或地质梯度。
