Species identification by SDS-PAGE of red algae used as seafood or a food ingredient

The identification, by SDS-PAGE, of four red algae used as sea vegetables o r ingredients by the food industry, was performed. They were Palmaria palma ta (Dulse), Chondrus crispus (Pioca), Porphyra umbilicalis (Nori), Gracilar ia verrucosa (Ogo-nori). For each species, variations in protein patterns w ere observed, according to the season. However, for all species, some prote in bands were always present during the yearly cycle of the plant. The refe rence pattern of P. palmata was composed of six protein bands with apparent molecular weights between 59.6 and 15.2 kDa. The G. verrucosa pattern was constituted of eight permanent bands. Two pattern bands, with apparent mole cular weights of 49.1 and 45.9 kDa,differentiated the G. verrucosa profile from other seaweed patterns. C. crispus could be identified by a reference pattern composed of seven bands; three, with close molecular weights (49.3; 46.2 and 43.2 kDa), were characteristic of this species. Finally, the P. u mbilicalis pattern showed seven bands with molecular weights between 73.1 a nd 15.9 kDa. The presence of a band with a molecular weight above 70 kDa ap peared to be specific to the Porphyra pattern. So the SDS.-PAGE seemed able to identify the four red species used by the food industry, but this analy tical method appeared to be applicable only to raw material dried in mild c onditions. (C) 2001 Elsevier Science Ltd. All rights reserved.