Species identification of raw and cooked bivalves using electrophoresis

Three electrophoretic techniques, isoelectric focusing (IEF), sodium dodecy l sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and urea-IEF were used for species identification of "baby-clams" from Vietnam (Meretrix lyra ta), grooved carpet shell (Ruditapes decussatus) and the common edible cock le (Cerastoderma edule). Analysis were performed on proteins extracted from different parts of the mollusks, adductor muscle. mantle, foot, of raw and cooked samples. The electrophoretic patterns of adductor muscle were the m ost discriminative. Although all three methods tested could be used for biv alve species identification, the electrophoretic profiles with IEF were mod ified after cooking, whereas those with SDS-PAGE or urea-IEF were identical in raw and cooked samples and thus more suitable for sample authentication .