Innovative Ultrasound-Assisted Approaches towards Reduction of Heavy Metals and Iodine in Macroalgal Biomass

• Main Authors: Estefanía Noriega-Fernández, Izumi Sone, Leire Astráin-Redín, Leena Prabhu, Morten Sivertsvik, Ignacio Álvarez, Guillermo Cebrián
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Foods
• Subjects: arsenic; cadmium; iodine; EDTA; brown macroalgae; <i>Laminaria hyperborea</i>
• Online Access: https://www.mdpi.com/2304-8158/10/3/649

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of <i>Laminaria hyperborea.</i> Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg⁻¹ of dry weight, respectively, were found in <i>L. hyperborea</i> blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in <i>L. hyperborea</i>, thus improving the product’s safety for consumers.