Studies on electrophoretic identification of fish species used in surimi(products) and their quality evaluation

Abstract

SDS-PAGE pattern of water soluble proteins and salt soluble proteins of raw fillets, surimi, sausage and different combinations (1:1; 3:1; 1:3; and 4:1) of surimi mixtures; sausage mixtures from the two species of fish, threadfin bream (Nemipterus japonicus), and bulls-eye (Priacanthus hamrur) were studied to see that whether these pattern are useful in identifying the species used for the preparation of surimi and sausage; and their quality evaluation. SDS-PAGE gave the effective species-specific pattern of raw fillets, surimi, sausage and surimi mixtures; sausage mixtures of extract of water and salt soluble proteins of threadfin bream and bulls-eye separately. Threadfin bream and bulls-eye were effectively identified by using their SDS-PAGE pattern of extract of water soluble proteins and salt soluble proteins separately. Threadfin bream and bulls-eye surimi and sausage were also effectively identified by comparing their SDS-PAGE pattern with species-specific SDS-PAGE pattern in their extract of water soluble proteins and salt soluble proteins separately. The SDS-PAGE pattern of water soluble proteins and salt soluble proteins were shown in this study to be effective in distinguishing the species specificity between threadfin bream and bulls-eye of raw fish fillets, surimi and sausage samples. Adultered/substituted species in the different mixture were identified by comparing their mixture SDS-PAGE pattern with species-specific SDS-PAGE pattern in their extract of water soluble proteins and salt soluble proteins separately. Different mixtures species-specific SDS-PAGE protein patterns can be used with reservation to detect/differentiate the adulteration/substitution in the fish mixtures, surimi and sausage when these two species mixed with the combinations of 1:1; 3:1; 1:3 and 4:1 ratios. The quality evaluation study showed that surimi, sausage and surimi mixtures; sausage mixtures of threadfin bream and bulls-eye used for the experiment were of good quality.