Freezing vegetables

Abstract

A process for the production of a frozen vegetable or part thereof, wherein said process comprises the steps: (i) subjecting a vegetable or part thereof to a firming treatment selected from: a) immersing the vegetable or part thereof in a solution of a calcium salt. b) heating the vegetable or part thereof to a temperature in the range 50 to 70° C., and c) a combination of a) and b); (ii) under-cooling to a core temperature of less than or equal to −5° C.; (iii) reducing the temperature to less than or equal to −18° C. The frozen vegetables, when thawed, possess a texture and appearance which closely resembles that of fresh vegetables.

1 . A process for the production of a frozen vegetable or part thereof, wherein said process comprises the steps of: 
 (i) subjecting a vegetable or part thereof to a firming treatment selected from: 
 a) immersing the vegetable or part thereof in a solution of a calcium salt.  
 b) heating the vegetable or part thereof to a temperature in the range about 50 to about 70° C., and  
 c) a combination of a) and b);  
   (ii) under-cooling said vegetable or part thereof to a core temperature of less than or equal to −5° C.;    (iii) reducing the temperature to less than or equal to −18° C.    
     
     
         2 . A process according to  claim 1  wherein said calcium salt is a member selected from the group consisting of calcium chloride, calcium sulphate, calcium citrate, calcium monophospate and mixtures thereof.  
     
     
         3 . A process according to  claim 2  wherein said solution of calcium salt comprises from 0.1 to 10% calcium.  
     
     
         4 . A process according to  claim 3  wherein said solution of calcium salt comprises about 1% calcium.  
     
     
         5 . A process according to  claim 3  wherein said vegetable or part thereof is immersed in the solution of calcium salt for a period of from 2 to 30 minutes.  
     
     
         6 . A process according to  claim 1  wherein said vegetable or part thereof is heated to a temperature of from about 50 to about 70° C. for a period of from about 2 to about 30 minutes.  
     
     
         7 . A process according to  claim 6  wherein said temperature is about 65° C.  
     
     
         8 . A process according to  claim 1  wherein said firming treatment comprises immersing the vegetable or part thereof in a solution of calcium salt at ambient temperature and immersing the vegetable or part thereof in an aqueous solution at a temperature of from about 50 to about 70° C. (with or without calcium salt being present) in either order.  
     
     
         9 . A process according to  claim 8  wherein said firming treatment comprises the steps of: 
 immersing said vegetable or part thereof in a solution of calcium salt at ambient temperature for a period of from about 2 to about 30 minutes; thereafter  
 immersing the vegetable or part thereof in a solution of calcium salt at a temperature of from about 50 to 70° C. for a period of from 2 to 30 minutes, and  
 optionally immersing the vegetable as part thereof in a solution of calcium salt for a period of from 2 to about 30 minutes.  
 
     
     
         10 . A process according to  claim 1  wherein at least 40% of ice formation within the core of said vegetable or part thereof in step (iii) occurs within a plurality of cellular structures, wherein the perimeter of each cellular structure is defined by a cell wall.  
     
     
         11 . A process according to  claim 1  wherein said vegetable or part thereof is a member selected from the group consisting of potato, swede, turnip, pumpkin, onion, broccoli, tomato, zucchini, aubergine, water chestnut, pepper, mushroom, peas, sugar-snap peas, spinach, green beans, carrot and mange tout.  
     
     
         12 . A process according to  claim 11  wherein said vegetable or part thereof is tomato.  
     
     
         13 . A process according to  claim 11  wherein said vegetable or part thereof is potato or carrot.  
     
     
         14 . A frozen vegetable obtained by a process which comprises the steps of: 
 (i) subjecting a vegetable or part thereof to a firming treatment selected from: 
 a) immersing the vegetable or part thereof in a solution of a calcium salt.  
 b) heating the vegetable or part thereof to a temperature in the range about 50 to about 70° C., and  
 c) a combination of a) and b);  
   (ii) under-cooling said vegetable or part thereof to a core temperature of less than or equal to −5° C.;    (iii) reducing the temperature to less than or equal to −18° C.    
     
     
         15 . A frozen meal comprising a vegetable or part thereof as defined in  claim 14 .  
     
     
         16 . Use of a vegetables as claimed in  claim 14  in a frozen meal.