Food preserving method and its device

Abstract

A food preserving method includes the step of housing a conductive food tray ( 2 ) in a cooling box ( 1 ), placing food ( 9 ) on the food tray ( 2 ) and cooling and preserving the food ( 9 ) with an AC voltage and a DC voltage being simultaneously applied to the food tray ( 2 ). After a DC-AC simultaneous application period during which the AC voltage and the DC voltage are simultaneously applied, the food ( 9 ) is cooled with only one of the DC voltage and the AC voltage being applied to the food tray ( 2 ). A food preserving device including a cooling box ( 1 ), a conductive food tray ( 2 ) housed in the cooling box ( 1 ), an AC power supply ( 3 ) used for applying an AC voltage to the food tray ( 2 ) and a DC power supply ( 4 ) used for applying a DC voltage to the food tray ( 2 ) is characterizing in that the AC voltage and the DC voltage are simultaneously applied to the food tray ( 2 ).

1 . A food preserving method comprising the steps of: 
 housing a conductive food tray ( 2 ) in a cooling box ( 1 );    placing a food ( 9 ) on the food tray ( 2 ); and    cooling the food ( 9 ) with an AC voltage and a DC voltage being simultaneously applied to the food tray ( 2 )    wherein the DC voltage is a negative voltage.    
   
   
       2 . The food preserving method according to  claim 1 , wherein after a DC-AC simultaneous application period during which the AC voltage and the DC voltage are simultaneously applied, the food ( 9 ) is cooled with only one of the DC voltage and the AC voltage being applied to the food tray ( 2 ).  
   
   
       3 . The food preserving method according to any one of claims  1  and  2 , wherein the cooling box ( 1 ) functions as a freezer for freezing the food ( 9 ).  
   
   
       4 . The food preserving method according to any one of claims  1  and  2 , wherein the cooling box ( 1 ) functions as a refrigerator for refrigerating the food ( 9 ).  
   
   
       5 . A food preserving device comprising: 
 a cooling box ( 1 );    a conductive food tray ( 2 ) housed in the cooling box ( 1 );    an AC power supply ( 3 ) used for applying an AC voltage to the food tray ( 2 ); and    a DC power supply ( 4 ) used for applying a DC voltage to the food tray ( 2 ), wherein    the AC voltage and the DC voltage are simultaneously applied to the food tray ( 2 ) and the DC voltage is a negative voltage.    
   
   
       6 . The food preserving device according to  claim 5 , further comprising a control unit ( 5 ) that controls a voltage application to the food tray ( 2 ) by the AC power supply ( 3 ) and the DC power supply ( 4 ).  
   
   
       7 . The food preserving device according to any one of claims  5  and  6 , wherein after a DC-AC simultaneous application period during which the AC voltage and the DC voltage are simultaneously applied, only one of the DC voltage and the AC voltage is applied to the food tray ( 2 ) by the control unit ( 5 ).  
   
   
       8 . The food preserving device according to any one of claims  5  and  6 , wherein the cooling box ( 1 ) functions as a freezer for freezing the food ( 9 ).  
   
   
       9 . The food preserving device according to  claim 7 , wherein the cooling box ( 1 ) functions as a freezer for freezing the food ( 9 ).  
   
   
       10 . The food preserving device according to any one of claims  5  and  6 , wherein the cooling box ( 1 ) functions as a refrigerator for refrigerating the food ( 9 ).  
   
   
       11 . The food preserving device according to  claim 7 , wherein the cooling box ( 1 ) functions as a refrigerator for refrigerating the food ( 9 ).