Effect of freezing on protein denaturation and gelling capacity of jumbo squid (Dosidicus gigas) mantle muscle

Abstract

The effect of freezing storage on protein denaturation and gelling capacity of jumbo squid muscle was evaluated. Squid mantle muscle samples were evaluated in both, ground (G) and whole presentations (W), and in a control consisting of ground muscle (C). G and W samples were submitted to two freezing storage periods (−20 °C), 1 day (GF-1, WF-1) and 30 d (GF-30, WF-30). Proximate composition, pH, surface hydrophobicity (SoANS) and differential scanning calorimetry (DSC) were evaluated. Additionally folding test, texture profile analysis and water holding capacity were monitored in gels prepared with the different samples. The quality of gels was not affected by any treatment. Neither freezing, grinding or storage period had a significant effect on the above parameters, suggesting that functional properties of the squid mantle muscle are highly stable. DSC did not reveal any denaturation, also adducing high stability of muscle proteins. SoANS revealed that freezing, grinding and time, had an effect on protein properties; however, these influences were apparently not significantly enough to have a further effect on the gel quality. Finally, gelling capacity of muscle was not affected by any factor. Considering these results, squid muscle may be considered as a useful resource either fresh or frozen.