Multi-scale protective effects of static magnetic field-assisted freezing on chicken breast during repeated freeze-thaw cycles: From quality attributes to gel properties

The repeated freeze-thaw (F-T) cycles in cold chain logistics are the key factor leading to the deterioration of frozen poultry meat quality. However, conventional freezing methods are limited in mitigating this damage. Herein, we employed static magnetic field-assisted freezing (SMFF) as a physical strategy to address this challenge. This study investigated the effects of SMFF at different intensities (3, 6, 9 mT) on the physicochemical quality, myofibrillar protein (MP) stability, and gelation properties of chicken breast after multiple F-T cycles. Results showed that SMFF effectively alleviated the cumulative damage caused by F-T cycles, with 3 mT showing the best protective effects among the tested intensities (3, 6, and 9 mT). At the tissue level, 3 mT SMFF preserved microstructural integrity, thereby improving water-holding capacity, as evidenced by a 41% reduction in thawing loss after the final F-T cycle. At the molecular level, the treatment inhibited MP oxidation and stabilized the protein conformation, as evidenced by a reduced random coil ratio and enhanced endogenous fluorescence during repeated F-T cycles. Consequently, MP from the 3 mT treatment group exhibited superior processing potential, with gel hardness and water-holding capacity significantly increased ( P < 0.05). Overall, SMFF effectively alleviates the quality decline caused by F-T cycles and maintains the processing potential of chicken breast, providing a promising strategy and theoretical reference for quality preservation in the frozen chicken industry.