MARE-Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal.
Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Molecules. 2022 Feb 15;27(4):1298. doi: 10.3390/molecules27041298.
The stalked barnacle is an abundant species on the very exposed rocky shore habitats of the Spanish and Portuguese coasts, constituting also an important economical resource, as a seafood item with high commercial value. Twenty-four elements were measured by untargeted total reflection X-ray fluorescence spectroscopy (TXRF) in the edible peduncle of stalked barnacles sampled in six sites along the Portuguese western coast, comprising a total of 90 individuals. The elemental profile of 90 individuals originated from several geographical sites ( = 15 per site), were analysed using several chemometric multivariate approaches (variable in importance partial least square discriminant analysis (VIP-PLS-DA), stepwise linear discriminant analysis (S-LDA), linear discriminant analysis (LDA), random forests (RF) and canonical analysis of principal components (CAP)), to evaluate the ability of each approach to trace the geographical origin of the animals collected. As a suspension feeder, this species introduces a high degree of background noise, leading to a comparatively lower classification of the chemometric approaches based on the complete elemental profile of the peduncle (canonical analysis of principal components and linear discriminant analysis). The application of variable selection approaches such as the VIP-PLS-DA and S-LDA significantly increased the classification accuracy (77.8% and 84.4%, respectively) of the samples according to their harvesting area, while reducing the number of elements needed for this classification, and thus the background noise. Moreover, the selected elements are similar to those selected by other random and non-random approaches, reinforcing the reliability of this selection. This untargeted analytical procedure also allowed to depict the degree of risk, in terms of human consumption of these animals, highlighting the geographical areas where these delicacies presented lower values for critical elements compared to the standard thresholds for human consumption.
蔓足类是西班牙和葡萄牙沿海暴露岩石栖息地中丰富的物种，也是一种重要的经济资源，因为它们是一种具有高商业价值的海鲜。使用非靶向全反射 X 射线荧光光谱法（TXRF）在葡萄牙西海岸六个地点采集的蔓足类可食用茎干中测量了 24 种元素，共 90 个个体。来自几个地理地点（每个地点 = 15 个）的 90 个个体的元素谱使用几种化学计量多元分析方法（重要变量偏最小二乘判别分析（VIP-PLS-DA）、逐步线性判别分析（S-LDA）、线性判别分析（LDA）、随机森林（RF）和主成分典范分析（CAP））进行分析，以评估每种方法追踪采集动物地理起源的能力。作为悬浮食者，该物种引入了高度的背景噪声，导致基于茎干完整元素谱的化学计量方法分类相对较低（主成分典范分析和线性判别分析）。应用 VIP-PLS-DA 和 S-LDA 等变量选择方法，根据收获区域显著提高了样本的分类准确性（分别为 77.8%和 84.4%），同时减少了分类所需的元素数量，从而减少了背景噪声。此外，所选元素与其他随机和非随机方法选择的元素相似，增强了这种选择的可靠性。这种非靶向分析程序还可以根据人类对这些动物的消费情况来描述风险程度，突出了这些美味佳肴在与人类消费标准阈值相比，关键元素含量较低的地理区域。
