Effects of pulsed electric fields based on molecular dynamics simulations on the cell membrane structure of salted beef under high salinity conditions

Molecular dynamics can be one of the most promising simulations at the molecular level. Traditional experiments can also be restricted to low controlling precision, in order to directly observe the dynamic changes. It is very necessary to accurately explore the cell membranes in the formation of nanochannels. In this study, an innovative framework was introduced to simulate the molecular dynamics of cell membranes and nanochannel formation using molecular dynamics. Two steps were set as the initial construction of a 3D structural model and subsequent dynamic simulation. The real structure and composition of the cell membrane were considered for the closely resembled construction of the 3D model. The impedance parameters of samples were determined under various processing. The impedance amplitude and phase angle were selected as the indicators of electrical impedance. The 3D structural model was constructed to sensitively reflect the structure and function of the cell membrane. Furthermore, 15 frequency points were identified in the range of 0.05 to 300 kHz during measurement. A broad spectrum was spanned from the low to the high frequencies. The impedance amplitude and phase angle of meat samples were assessed before and after treatment. Comparative analysis revealed that the varying processing was significantly impacted on the integrity of the cell membrane. The evidence was from the changes in the impedance amplitude and phase angle. A 10 nm × 10 nm × 10 nm lipid bilayer structure model was constructed to further validate. The actual structure of the cell membrane was extracted to perform the molecular dynamics simulation. The overall structure of the lipid bilayer was evaluated during the simulation, including the density distribution, mean square displacement, and radial distribution function. The results indicated that the impedance amplitude of the sample decreased with the increasing electric field strength within experimental conditions, while the phase angle increased gradually. A stable configuration was maintained in the lipopolysaccharide and phospholipid layers in the cell membrane structure, in the absence of an electric field and high salt. No nanochannel structure was observed without any loosening or dissociation. Once an electric field of 4 kV/cm was applied, the nanochannel was outstandingly formed. As such, the significant effect of an electric field on the cell membrane structure, thus inducing the nanochannel formation. In the high-salt systems, the NaCl ions tended to preferentially traverse these nanochannels. The channel structure was then stabilized to enhance its stability. Furthermore, the 8% NaCl solution failed to disrupt the order and structural dimension of the cell membrane at physiological levels. Fortunately, the pulsed electric field was also introduced to accelerate the migration of lipid bilayer molecules. Ultimately, the nanochannels were formed to disrupt the integrity of the cell membrane. This degree of disruption was closely related to the strength of the electric field. Additionally, the NaCl solution also played a positive role in the porous structure and its stability in the high-salt system. These findings can provide an important basis for a better understanding of the molecular dynamics of cell membranes and the formation of nanochannels. The brining treatment can also be optimized to design the nanopores.