CONTRIBUTION OF ELECTROPHORESIS TO THE IDENTIFICATION OF RED SEAWEEDS (GRACILARIA SP) USED AS FOOD INGREDIENTS

Gracilaria seaweeds are used for agar (E 406) production and are also available in several countries as sea vegetables or ingredients in food product formulations. A rapid extraction procedure from three species (Gracilaria compressa, G. verrucosa, G. foliifera) using demineralised water and sonication produces algal proteic fractions, SDS PAGE shows specific markers for G. compressa and G. foliifera. Two bands with an apparent molecular weight higher than 100,000 distinguish G. compressa from the other two algae. G. compressa possesses also three specific markers with apparent molecular weights of 42,400, 34,400 and 24,000. G. foliifera is identified by the presence of a single band with an apparent molecular weight higher than 100,000 and a band with an apparent molecular weight of 26,400. No specific markers is found in G. verrucosa. Generally used for the identification of terrestrial plants, electrophoresis proves to be an appropriate tool for caracterisation of some seaweed species belonging to the genus Gracilaria.