Spatial variability of elemental fingerprints of sea lettuce (Ulva spp.) and its potential use to trace geographic origin

Abstract

Seaweeds are an important marine resource and are currently used in a wide range of applications, such as food, feed, pharmaceuticals, cosmetics, nutraceuticals, and biomaterials. Seaweeds uptake a multitude of chemical elements from the environment, which can turn them into high-quality food products or pose a threat to human health. Therefore, knowing the elemental fingerprint of seaweeds, as well as their geographic origin, is of utmost importance for their valorization and to safeguard public health. In the present study, the elemental fingerprint of the green seaweed Ulva spp., popularly known as sea lettuce, was determined. Different samples were sourced from nine different locations over the western and southwestern Iberian coast, and elemental fingerprints targeted three major elements (Ca, K and Na) and seven trace elements (Al, Ba, Cu, Fe, Mn, Pb and Zn). The elemental fingerprints of Ulva spp. differed significantly among the different places of origin, confirming the potential of this biogeochemical tool to trace the geographic origin of seaweeds. Origin certification can contribute towards the valorization of premium Ulva spp. biomass and enhance safety standards for high-end uses of this green seaweed.