Effects of nanowarming on water holding capacity, oxidation and protein conformation changes in jumbo squid (Dosidicus gigas) mantles

Abstract

To study the effects of nanowarming on the water holding capacity (WHC), oxidation, and protein conformation of jumbo squid mantles, jumbo squid mantles were subjected to cold storage thawing (CST), microwave thawing (MT), and magnetic nanoparticles plus microwave thawing (MNPMT). Thawing loss, centrifugal loss and low-field nuclear magnetic resonance (LF-NMR) were used to study WHC. Carbonyl content, total sulfhydrylcontent and dityrosine content were carrid out to observe protein oxidation. Protein solubility, particle size and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were conducted to analyze protein denaturation and aggregation. Raman spectra before and after isotope H/D exchange illustrated changes in protein structure. Optical microscopy showed that MNPMT can inhibit the recrystallization of ice crystals during thawing, making the jumbo squid fiber structure more compact. Compared with CST and MT, MNPMT can reduce protein oxidation and lipid oxidation during thawing, reducing the damage of ice crystals to muscle fibers and improving WHC. This study showed that the MNPMT is an effective method to achieve high thawing rate and the uniformity of temperature rewarming for frozen jumbo squid, and provided a theoretical basis for exploration of nanowarming techniques in the food industry.