Electrochromic Properties and Electrochemical Behavior of Marennine, a Bioactive Blue-Green Pigment Produced by the Marine Diatom <i>Haslea ostrearia</i>

• Main Authors: Nellie Francezon, Mickaël Herbaut, Jean-François Bardeau, Charles Cougnon, William Bélanger, Réjean Tremblay, Boris Jacquette, Jens Dittmer, Jean-Bernard Pouvreau, Jean-Luc Mouget, Pamela Pasetto
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Marine Drugs
• Subjects: marennine; marennin; <i>Haslea ostrearia</i>; microalgae; diatom; natural blue pigment
• Online Access: https://www.mdpi.com/1660-3397/19/4/231

Marennine has long been known as the unique peculiar pigment responsible for the natural greening of oysters. It is specifically produced by the marine diatom <i>Haslea ostrearia</i> and it is a natural blue molecule indeed promising for food industry because of the rarity of such non-toxic, blue-colored pigments. In the search for its still not defined molecular structure, investigation of the color changes with the redox state has been carried out combining different approaches. Reducing and oxidizing chemicals have been added to purified marennine solutions and a stable blue-green color has been confirmed for the oxidized state, while a yellow color corresponded to the reduced unstable state. Raman spectroscopy has been used to monitor changes in the Raman spectra corresponding to the different colored states, and cyclic voltammetry has allowed the detection of a redox system in which protons and electrons are exchanged. These findings show that marennine is a suitable stable blue pigment for use in food applications and help in the elucidation of the chromophore structure.