Mechanism of needle electrode-derived pulsed electric fields on the structural and physicochemical properties of pork...

This research examined the impacts of needle pulsed electric field (PEF) treatment on the structural and physicochemical characteristics of porcine myofibrillar proteins (MP). It investigates the mechanisms by which PEF promotes curing, primarily from the perspectives of cell membrane permeability, myofibril rupture, and protein denaturation. The results showed that the cell disintegration index was significantly increased by 22.2 % (P < 0.05) when the PEF intensity was increased from 1.0 kV/cm to 3.0 kV/cm. Low-field nuclear magnetic resonance (LF-NMR) analysis revealed that the PEF treatment increased the water retention inside myofibrils. Fourier transform infrared spectroscopy (FT-IR) analysis indicated that PEF treatment resulted in an increase in α-helix, β-turns and irregular curls, and a decrease in β-folding content of MP. Differential scanning calorimetry (DSC) results demonstrated that PEF treatment decreased the denaturation temperature (Tm) of MP, but the Tm recovered with increasing field strength. Transmission electron microscopy (TEM) observations revealed that PEF treatment myofibrils gaps became larger and in the 3.0 kV/cm treatment group with a looser structure. These changes indicated that PEF treatment enhanced the hydrophilicity and hydrolysis of MP by changing its structure, which promoted the penetration and binding of NaCl. The results of the study further explored the mechanism of needle electrode-derived PEF treatment could accelerate the curing of pork and provided a theoretical basis for the utilization of PEF technology in pork curing.