Influence of the Capture Method on the Physicochemical and Functional Properties of Myofibrillar Proteins of Fin from Frozen, Stored Squid (Illex argentinus)

Abstract

The physicochemical and functional properties of actomyosin from fins of frozen, stored squid caught either by jigging machines (AME1) or by trawling (AME2) were investigated. At time 0 SDS-PAGE, 10% of AMEl and AME2 showed the characteristic polypeptide bands of myofibrillar proteins and two components of 155 kDa and 55 kDa. Both the degradation of the myosin heavy chain and an increase in the 155-kDa component occurred earlier in AME2. Irrespective of the capture method used, no significant changes in protein solubility and a decrease (P < 0.05) in reduced viscosity were observed in both AMEl and AME2. Surface hydrophobicity (SoANS) of AMEl increased (P < 0.05) during the first month of storage and remained unchanged thereafter. The SoANS of AME2 was unchanged. The initial value of SoANS of AME2 was higher than that of AMEl. The emulsion activity index and the emulsion stability of AME2 increased (P < 0.05) during the first month of storage, whereas the emulsion activity index and emulsion stability of AMEl remained unchanged during the frozen storage period. These results indicate that the capture method influences the rate of autolysis and the functional properties of myofibrillar proteins of fin from frozen, stored squid.