Design of a Supercooling Device for Extended Shelf Life of Perishable Foods

In conventional refrigerators food items are frozen among ice crystals and their quality is compromised once they are thawed. The deterioration of quality may include generation of drips, protein denaturation and changes in the cellular structure of foods. The occurrence of ice crystallization can be prevented by the phenomenon called supercooling that involves temperature reduction below the freezing point of the sample.Supercooling involves cooling of biological samples below a phase transition temperature in a balanced state leading to prevention of their cellular activity. In this supercooled state, damage by freezing such as protein denaturation and cellular structure injuries can be avoided. This ability to preserve the biological samples such as cell culture, tissues and organs at subzero temperature is useful in pharmaceutical, biotechnological, food and other medical related industries. The research to sustain and maintain food and biological samples in a supercooled state is drawing major attention and promises to hold great potential in the near future.In order to enhance preservation technology over the existing art, the subject invention proposes a method and a device to preserve the quality of foods by treating them with a pulsed electric field and an oscillating magnetic field in combination. The proposed invention maintains perishable foods (such as beef and fish), in a supercooled state at around -4 ~ -6°C far below their equilibrium freezing points, and their original freshness is kept intact for transportation and storage purposes. Unlike other few supercooling methods based on the precision temperature control, our supercooling invention is insensitive to environmental disturbances causing ice nucleation, presumably due to 'memory effects' of magnetic field on water molecules. The invention may be extended to biomedical applications as well, such as preservation of cell cultures, proteins, and tissues and organs transport at subzero temperatures.