Supercooling Phenomenon of Magnetic Field-Assisted Freezing and its Impacts on Quality Preservation of Frozen Fruits and Vegetables

Supercooling preservation of fruits and vegetables (FV) is critical to food freezing. Magnetic field (MF)-assisted freezing of FV promotes supercooling; but its phenomenon is yet to be uncovered. Therefore, information on the supercooling phenomenon of MF-assisted freezing and its impacts on the quality preservation of frozen FV is critical to cellular food freezing manufacturing practices. This study reported on the supercooling phenomenon of MF-assisted freezing and its impacts on the quality preservation of frozen FV. Intrinsic factors (hydrogen bonding ordering and geometry) related to product, and extrinsic factors (types of magnetic field, field intensity, and exposure time) related to process parameters, that influenced supercooling were discussed. The study revealed that the occurrence of supercooling during MF-assisted freezing depends mainly on the types of magnetic field applied, field intensity and the direction of the applied field, which affects the effective magnetic lines of force resulting to uncompensated electron spins through samples. The exhibition of electron spins increases the order of magnetic ions and water molecules contained in cellular foods. For process design, more in-depth study and accurate understanding of the supercooling phenomenon of MF-assisted freezing and its impacts on the quality preservation of frozen FV are essential. It is hoped that this study provide better insight on the supercoling phenomenon of MF-assisted freezing and its impacts on the quality preservation of frozen FV for further studies.

Practical Applications: Application of high intensity magnetic field to cellular food freezing assists supercooling phenomenon, with advantage of enhancing quality. But the development as well as market acceptance of the technology is low because the supercooling phenomenon is not well-understood. Currently, insightful studies on the supercooling phenomenon of magnetic field-assisted freezing and its impacts on quality preservation of fruits and vegetables have been unveiled. The studies revealed that the strong magnetic field assistance to freezing is possible through the exhibition of electron spins and re-ordering of magnetic ions of water molecules contained in cellular foods. However, the results outlined in this study offer comprehensive insights into the supercooling phenomenon of magnetic field-assisted freezing and its impacts on the freezing process and the quality preservation of fruits and vegetables, offering valuable guidance for future developments of strong magnetic field-assisted freezing technology.