FIELD: refrigeration.
SUBSTANCE: invention relates to the field of freezing foods and is intended to prevent the crystallisation of water in foods in the water to ice phase transition. Proposed is a method for freezing water-containing foods, including rapid cooling of the food, started while simultaneously creating a non-homogeneous alternating electric field around the frozen food; wherein the non-homogeneous alternating electric field is created using electrode matrices, and the directions, speed and nature of movements of static gradients of intensity of the electric field at each point of the field are controlled by organising reciprocating cycles of movement of areas of the static gradient of intensity of the electric field along the horizontal plane of the cooled object; for the entire period of the water to ice phase transition by connecting electrode potentials on the matrices of the field modulator, the control over the directions, speed and nature of movements of static gradients of intensity of the electric field organises the cyclic movement of water dipoles along closed trajectories, forming crystal-free glass-like ice; wherein the impact of the non-homogeneous alternating electric field is imparted until the water to ice phase transition is complete, which is determined by a reduction in the conductivity of the food, and the rapid cooling is continued until the food reaches the storage temperature set in the range from -15°C to -20°C; wherein the distance between the matrices of the field modulator is from 50 to 150 mm, the pitch of the electrodes in the matrices of the field modulator is 10 mm, and the cyclic frequency of movement of areas of static gradient of intensity of the electric field is from 20 to 100 Hz. The non-homogeneous electric field is also created using planar or volumetric matrices of the field modulator. Electrodes of the matrices of the field modulator can be of the point, linear or planar type. The voltage on the electrodes of the matrices of the field modulator is from 3 to 70 kW. The frequency of the alternating field is from 1 kHz to 20 kHz. Each change in the direction of movement of static gradients of intensity of the electric field is accompanied by an inversion of the areas of static gradients of the electric field by 180 degrees.
EFFECT: invention is aimed at fully preventing the formation of ice crystals when freezing foods, rapidly and effectively removing heat from the food, preserving the organoleptic properties, physical and chemical characteristics of foods as objects of freezing for a long time.
6 cl, 7 dwg, 3 tbl
