Pasteurization System for Root Vegetables

Abstract

A system and method for pasteurizing the surface of a food product includes a flame pasteurizing means arranged to transfer heat to an outer layer of the food product as it is carried by a cook belt. The flame pasteurizing means provides a medium that engulfs more than 50% of the surface area of the skin or outer layer and raises the temperature of the outer layer to at least 145° F. (about 62.8° C.). A washing means, arranged at an exit point of the flame pasteurizing means, removes the raised temperature outer layer and stops heat transfer to an adjacent inner layer of the food product. The pasteurized and washed product retains the same color and flavor as that of the unpasteurized product.

What is claimed: 
     
         1 . A system for pasteurizing the surface of a food product, the system comprising:
 a flame pasteurizing means arranged to transfer heat to an outer layer of the food product being carried by a cook belt, the flame pasteurizing means providing a medium that engulfs more than 50% of the surface area of the outer layer and raises the temperature of the outer layer to at least 145° F. (about 62.8° C.); and   a washing means arranged at an exit point of the flame pasteurizing means, the washing means removing the raised temperature outer layer and stopping heat transfer to an adjacent inner layer of the food product.   
     
     
         2 . A system according to  claim 1  wherein a core temperature of the food product remains unchanged between an entry point to the flame pasteurizing means and an exit point of the washing means. 
     
     
         3 . A system according to  claim 1  wherein an appearance of the food product immediately after an exit point of the washing means is the same as the appearance of the food product immediately prior to entering the flame pasteurizing means. 
     
     
         4 . A system according to  claim 1  wherein the food product resides between an entry point to the flame pasteurizing means and the exit point of the flame pasteurizing means for an amount of time required to achieve a 1 log reduction in a pathogen residing on the outer layer of the product. 
     
     
         5 . A system according to  claim 1  wherein the food product resides between an entry point to the flame pasteurizing means and the exit point of the flame pasteurizing means for at least 30 seconds and no longer than 90 seconds. 
     
     
         6 . A system according to  claim 5  wherein the food product resides between the entry to the flame pasteurizing means and the exit point of the flame pasteurizing means for at least 45 seconds and no longer than 60 seconds. 
     
     
         7 . A system according to  claim 1  wherein the flame pasteurizing means engulfs at least 65 percent of the surface area of the food product. 
     
     
         8 . A system according to  claim 1  wherein the flame pasteurizing means includes at least one continuous ribbon burner arranged about the cook belt. 
     
     
         9 . A system according to  claim 7  wherein the at least one continuous ribbon burner is arranged at an oblique angle to the cook belt. 
     
     
         10 . A system according to  claim 1  wherein the amount of weight loss of the food product after passing through the system is no more than 5%. 
     
     
         11 . A system according to  claim 1  wherein the food product is a root vegetable. 
     
     
         12 . A method for pasteurizing the surface of a food product, the method comprising the steps of:
 arranging a food product on a cook belt, the food product being in an unpeeled state and not touching any adjacent food product on the cook belt; and   passing the food product through a flame pasteurizing means, the flame pasteurizing means arranged to transfer heat to an outer layer of the food product, the flame pasteurizing means providing a medium that engulfs more than 50% of the surface area of the outer layer and raises the temperature of the outer layer to at least 145° F. (about 62.8° C.); and   passing the flame-pasteurized food product through a washing means, the washing means removing the raised temperature outer layer of flame-pasteurized food product and stopping heat transfer to an adjacent inner layer of the flame-pasteurized food product.   
     
     
         13 . A method according to  claim 12  wherein a core temperature of the food product remains unchanged between an entry point to the flame pasteurizing means and an exit point of the washing means. 
     
     
         14 . A method according to  claim 12  wherein an appearance of the food product immediately after an exit point of the washing means is the same as the appearance of the food product immediately prior to entering the flame pasteurizing means. 
     
     
         15 . A method according to  claim 12  wherein the food product resides between an entry point to the flame pasteurizing means and the exit point of the flame pasteurizing means for an amount of time required to achieve a 1 log reduction in a pathogen residing on the outer layer of the product. 
     
     
         16 . A method according to  claim 12  wherein the food product resides between an entry point to the flame pasteurizing means and the exit point of the flame pasteurizing means for at least 30 seconds and no longer than 90 seconds. 
     
     
         17 . A method according to  claim 16  wherein the food product resides between the entry to the flame pasteurizing means and the exit point of the flame pasteurizing means for at least 45 seconds and no longer than 60 seconds. 
     
     
         18 . A method according to  claim 12  wherein the flame pasteurizing means engulfs at least 65 percent of the surface area of the food product. 
     
     
         19 . A method according to  claim 12  wherein the flame pasteurizing means includes at least one continuous ribbon burner arranged about the cook belt. 
     
     
         20 . A method according to  claim 19  wherein the at least one continuous ribbon burner is arranged at an oblique angle to the cook belt. 
     
     
         21 . A method according to  claim 12  wherein the amount of weight loss of the food product after passing through the system is no more than 5%. 
     
     
         22 . A method according to  claim 12  wherein the food product is a root vegetable.