Effect of Heating on Protein Denaturation, Water State, Microstructure, and Textural Properties of Antarctic Krill (Euphausia superba) Meat

Antarctic krill (Euphausia superba) is an important source of biomass and high-quality protein. However, heat treatment negatively impacts the quality of Antarctic krill and compromises its utilization in the food industry. This study aimed to investigate the mechanisms underlying changes in Antarctic krill meat characteristics and physicochemical properties treated at different temperatures and holding times. Our findings indicated that hardness and cooking loss of Antarctic krill meat increased dramatically at higher temperatures and holding times. The low-field nuclear magnetic resonance (LF-NMR) analysis revealed that the loss of immobilized water increased, whereas the SDS-PAGE analysis showed that the content of myosin heavy chain decreased significantly and that protein degradation occurred. Fourier transform infrared spectroscopy (FT-IR) and intrinsic fluorescence spectra suggested that α-helix motifs were transformed into β-sheets and that more hydrophobic groups were exposed. The scanning electron microscopy (SEM) results showed that Antarctic krill meat formed corrugated folded regions after heat treatment without forming a three-dimensional water-entrapped structure, which led to significant water loss, resulting in rapid deterioration of Antarctic krill meat. These results provide the basis for a deeper understanding of the processing characteristics of Antarctic krill meat.