Elemental profiling of red seaweed Neopyropia yezoensis used in fast authenticating the geographical origin and food safety assessment

The red seaweed Neopyropia yezoensis is one of the predominant seaweeds cultivated and consumed in China. Its quality characteristics and economic value are closely influenced by the environmental conditions. So developing a fast method to trace the geographical origins of N. yezoensis is urgent because it concerns consumers knowing the origin of the product, nutritional value and safety. In present work, the elemental profiling in a total of 132 subsamples of N. yezoensis collected from five areas along the eastern and northern coast of China was established. Results showed that the content of K was the highest among the analyzed elements, and the Na/K ratio in N. yezoensis was 0.37. The consumption of N. yezoensis was confirmed to be a good source of essential dietary elements. However, high levels of Cd must attract consumers' attention, because about 20.5% of the samples was not compliant with the current European regulations. The influence of the geographical origin have a great difference on element profile. The linear discriminant analysis (LDA) with the stepwise method showed that the samples from Liaoning Province and Shandong Province could be well distinguished from those from Jiangsu Province. Based on the leave-one-out cross-validation method, the predictive ability was 80.3%, indicating a good performance of elemental fingerprints in fast authenticating of the origin of N. yezoensis in China. This discrimination made it possible to simultaneously characterize the samples according to their nutritional value and human consumption safety levels.