Food freezing and thawing method and apparatus

Abstract

A method of freezing food for later thawing and use which includes the steps of packing a food product in a container for freezing, cooling the food substantially throughout the bulk thereof to about 10° C. and then cooling the food substantially throughout the bulk thereof preferably from about 10° C. to about −10° C. in approximately 10 minutes to less than approximately 40 minutes.

1 . A method of freezing food for later thawing and use, said method comprising steps of:
 packing the food product in a sealed container for freezing;   cooling the food product substantially throughout the bulk thereof to approximately 10° C. to 0° C. in approximately 1 to 10 minutes; and   cooling the food product substantially throughout the bulk thereof to approximately 0° C. to −10° C. in approximately 10 to 40 minutes;   wherein said cooling steps comprise placing the food product in a calorie exchange relationship with circulating air and dry ice in a high calorie exchange cooling unit.   
   
   
       2 . The method as recited in  claim 1 , wherein the food product is cooled to approximately 6° C. to 0° C. in approximately 1 to 10 minutes. 
   
   
       3 . The method as recited in claim l, wherein the food product is cooled to approximately 0° C. to −7° C. in approximately 10 to 40 minutes. 
   
   
       4 . The method as recited in  claim 1 , wherein the food product is cooled to approximately 10° C. to 0° C. in approximately 3 to 5 minutes. 
   
   
       5 . The method as recited in  claim 1 , wherein the food product is cooled to approximately 0° C. to −10° C. in approximately 15 to 30 minutes. 
   
   
       6 . The method as recited in  claim 3 , wherein the food product is cooled to approximately 0° C. to −7° C. in approximately 15 to 30 minutes. 
   
   
       7 . The method as recited in  claim 2 , wherein the food product is cooled to approximately 6° C. to 0° C. in approximately 3 to 5 minutes. 
   
   
       8 . The method as recited in  claim 1 , wherein the second cooling step is performed at a substantially steady rate. 
   
   
       9 . The method as recited in  claim 1 , wherein said food product is sushi. 
   
   
       10 . (canceled) 
   
   
       11 . The method as recited in  claim 1 , wherein said packing step includes vacuum bagging said food product. 
   
   
       12 . The method as recited in  claim 1 , wherein the high calorie exchange cooling unit is a freezer having an ambient temperature of approximately −40° C. to −70° C. and a variable cooling feature and cooling step includes:
 (a) placing the food product into the freezer;   (b) adjusting said variable cooling feature to ensure the food product is cooled substantially throughout the bulk thereof from about 10° C. to about −10° C. in less than approximately 40 minutes; and   (c) removing said food product from said freezer after the temperature of said food product reaches a predetermined temperature that is lower than approximately −10° C.   
   
   
       13 . The method as recited in  claim 12 , wherein the adjusting step (b) includes controlling a circulation of air within said freezer. 
   
   
       14 . The method as recited in  claim 12 , wherein the adjusting step (b) includes directing a supply of liquid carbon dioxide into said freezer. 
   
   
       15 . The method as recited in  claim 12 , wherein the adjusting step (b) includes controlling an incident angle between dry ice in said freezer and a circulation of air within said freezer. 
   
   
       16 . The method as recited in  claim 14 , wherein the supply of liquid carbon dioxide is terminated when the temperature of said food product reaches approximately −5° C.-7° C. 
   
   
       17 . A method of freezing a food product, said method comprising steps of:
 (1) packaging a food product to be frozen after a temperature of said food product reaches a first predetermined temperature;   (2) cooling said food product until the temperature of said food product reaches a second predetermined temperature; and   (3) cooling said food product so that the temperature of said food product decreases from said second predetermined temperature to a third predetermined temperature within a first predetermined period of time;   wherein said cooling steps comprise placing said food product in a calorie exchange relationship with circulating air and dry ice in a high calorie exchange cooling unit.   
   
   
       18 . The method as recited in  claim 17 , wherein said second predetermined temperature and said third predetermined temperature are selected to define a temperature range wherein said food product is subject to at least one of accelerated aging and maximum ice crystallization generation. 
   
   
       19 . The method as recited in  claim 17 , wherein said first period of time is selected to minimize at least one of aging and ice crystallization generation of said food product during said cooling step (3). 
   
   
       20 . The method as recited in  claim 17 , wherein a fourth predetermined temperature is selected between said second and third predetermined temperatures such that said second and fourth predetermined temperatures define a temperature range wherein said food product is subject to accelerated aging and the third and fourth predetermined temperatures define a temperature range wherein said food product is subject to maximum ice crystallization generation, said first period of time is divided into second and third periods of time, said second period of time corresponding to the amount of time the temperature of said food product will be within said temperature range wherein said food product is subject to accelerated aging, said third period of time corresponding to the amount of time the temperature of said food product will be within said temperature range wherein said food product is subject to maximum ice crystallization generation, and said second and third periods of time are selected to minimize respective aging and ice crystallization generation of said food product during said cooling step (3). 
   
   
       21 . The method as recited in  claim 17 , wherein said first predetermined temperature is approximately 15° C. to 40° C. 
   
   
       22 . The method as recited in  claim 17 , wherein said second predetermined temperature is approximately 10° C. to 0° C. 
   
   
       23 . The method as recited in  claim 17 , wherein said third predetermined temperature is approximately 0° C. to −10° C. 
   
   
       24 . The method as recited in  claim 17 , wherein said first predetermined period of time is approximately 10 to 40 minutes. 
   
   
       25 . The method as recited in  claim 22 , wherein said second predetermined temperature is approximately 6° C. to 0° C. 
   
   
       26 . The method as recited in  claim 23 , wherein said third predetermined temperature is approximately 0° C. to −7° C. 
   
   
       27 . The method as recited in  claim 24 , wherein said first predetermined period of time is approximately 15 to 30 minutes. 
   
   
       28 . The method as recited in  claim 17 , wherein said second predetermined temperature is reached in approximately 1 to 10 minutes. 
   
   
       29 . The method as recited in  claim 28 , wherein said second predetermined temperature is reached in approximately 3 to 5 minutes. 
   
   
       30 - 63 . (canceled) 
   
   
       64 . The method of  claim 1 , wherein the packing step includes de-aeration. 
   
   
       65 . The method of  claim 1 , wherein the packing step includes shrink wrapping. 
   
   
       66 . The method of  claim 17 , wherein the packaging step includes packaging in a sealed container. 
   
   
       67 . The method of  claim 66 , wherein the packaging step includes de-aeration. 
   
   
       68 . The method of  claim 66 , wherein the packaging step includes vacuum bagging. 
   
   
       69 . The method of  claim 66 , wherein the packaging step includes shrink wrapping.