Effects of Oscillating Magnetic Fields of Different Level of Intensity Magnitudes on Supercooling of Cherries

Supercooling has numerous applications in the bio-preservation and food cold chain. This study investigated the effects of oscillating magnetic fields at different intensity levels on the preservation of cherries during supercooling. The magnetic field frequency was 50 Hz, and by applying the magnetic field of 0.1 mT level and mT level intensity, the experiment demonstrated that the magnetic field of mT level could better maintain the degree of supercooling of cherries, and realized 24 h supercooling storage at − 4 ℃. The supercooled samples exhibited food quality comparable to that of the fresh samples, with weight loss in the supercooled samples reduced by 73.2% in comparison to the control group. The mechanism of the effect of different level of magnetic energy density on cherry supercooling is explored from the macroscopic point of view of thermodynamic and the microscopic point of view of hydrogen bonding of water molecules. The oscillating magnetic field makes the Gibbs free energy of water molecules as a whole rise, which leads to a larger energy barrier required for crystallization. In addition, the magnetic field inhibits crystallization by weakening the hydrogen bonding within the water molecule clusters so that the water molecule cluster size does not reach the critical radius. To a certain extent the higher the magnetic energy density, about less prone to freezing under the same supercooling conditions, providing a reference for the future determination of the lowest magnetic energy density for different fruits, and helping to reduce the energy consumption of this technology.