Low-voltage electric field assisted freezing of pork: an insight into the enhancement on the stability of colloid and myofibril protein in cryopreservation

• Electric field parameters for LVEF-assisted freezing were screened. • LVEF remarkably shorten the freezing curve of the pork. • LVEF preserved water-holding capacity and texture integrity during freezing. • LVEF suppressed myofibrillar protein oxidation/denaturation in frozen pork. This study investigated the effects of low-voltage electric field (LVEF: 0-8 kV, 30-250 Hz, 7.5-45 cm electrode spacing)-assisted freezing on pork quality subjected to 90-day cryopreservation at -18°C. Parameters (2 kV, 50 Hz, 30 cm) of LVEF were fixed via freezing curve analysis. Further analysis indicated that LVEF remarkably improved water-holding capacity and maintained textural properties (hardness, gel strength, shear force) of the frozen pork in following cryopreservation, which might be attributed to less mechanical damage to myofibrils. Moreover, myofibrillar protein (MP) stability analysis revealed that LVEF treatment decreased carbonyl content (35.4%), surface hydrophobicity (32.8%), and fragmentation index (26.1%), while improving total sulfhydryl retention and solubility. Fourier transform infrared and Raman spectroscopy revealed increased α-helix (25.0%) and β-sheet (28.0%) proportions, along with enhanced endogenous fluorescence intensity in LVEF-treated MP, indicating superior secondary structural integrity. These findings suggested that LVEF effectively maintained MP stability by inhibiting protein oxidation and aggregation, which may open a new horizon for meat cryopreservation.