Method and apparatus for sterilizing and filling containers

Abstract

A method, apparatus and system for low-temperature hot-filling of a flowable food product into a sterilized container is disclosed herein. The low-temperature hot-filling temperature preferably ranges from 60° C. to 82.2° C. The method applies a solution of hydrogen peroxide onto the packaging and an alkaline solution to react with the hydrogen peroxide to generate hydroxyl radicals to kill microorganism. The use of an alkaline solution allows the sterilization process to proceed at a lower temperature and a faster rate. A solution of sodium hydroxide is the preferred alkaline solution. The temperature of the process is preferably below 100° C.

1 . A method for aseptically hot-filling a PET bottle, the method comprising: 
 applying a hydrogen peroxide solution having from 1% to 50% hydrogen peroxide to pre-crystallized PET bottle, the hydrogen peroxide solution applied at a temperature ranging from 35° C. to 100° C.;    permitting the hydrogen peroxide solution to activate on the pre-crystallized PET bottle for an activation period;    applying an alkaline solution to the pre-crystallized PET bottle subsequent to the activation period, the alkaline solution having a pH in the range of 10-14, the alkaline solution applied at a temperature ranging from 35° C. to 100° C.;    rinsing the pre-crystallized PET bottle to remove the residue alkaline solution and residue hydrogen peroxide to create a sterilized PET bottle;    conveying the sterilized PET bottle to a filling station;    hot-filling a fluid food product into the sterilized PET bottle at the filling station to create a hot-filled PET bottle, the temperature of the fluid food product ranging from 140° F. to 180° F. during the hot-filling; and    cooling the hot-filled PET bottle at a temperature less than 100° F. for a period of time ranging from ten seconds to ten minutes.    
     
     
         2 . The method according to  claim 1  wherein the alkaline solution is a sodium hydroxide solution, a potassium hydroxide solution or a ferrous sulfate solution.  
     
     
         3 . The method according to  claim 1  wherein the alkaline solution is a solution of 0.05 Normal sodium hydroxide having a pH of approximately 12.5.  
     
     
         4 . The method according to  claim 1  wherein the alkaline solution is first applied to the PET bottle and then the solution of hydrogen peroxide is applied to the PET bottle to react with the alkaline solution to generate active oxygen species and/or hydroxyl radicals.  
     
     
         5 . The method according to  claim 1  wherein the solution of hydrogen peroxide is first applied to the PET bottle and the activation period is 30 seconds and then the alkaline solution is applied to the PET bottle to reaction with the hydrogen peroxide to generate hydroxyl radicals.  
     
     
         6 . A method for aseptically hot-filling a PET bottle, the method comprising: 
 applying a hydrogen peroxide solution having from 1% to 50% hydrogen peroxide to a pre-crystallized PET bottle, the hydrogen peroxide solution applied at a temperature no greater than 65° C.;    permitting the hydrogen peroxide solution to activate on the pre-crystallized PET bottle for an activation period ranging from 1 second to 30 seconds;    applying an alkaline solution to the pre-crystallized PET bottle subsequent to the activation period, the alkaline solution having a pH in the range of 10-14, the alkaline solution applied at a temperature no greater than 65° C.; and    rinsing the pre-crystallized PET bottle with sterile water to remove the residue alkaline solution and residue hydrogen peroxide;    filling the sterilized pre-crystallized PET bottle with a fluid food product within a sterile environment to create a hot-filled PET bottle, the fluid food product having a temperature ranging from 140° F. to 180° F.;    sealing the hot-filled PET bottle with a sterilized seal to create a seal hot-filled PET bottle;    cooling the sealed hot-filled PET bottle at a temperature less than 100° F. for a period ranging from ten seconds to ten minutes.    
     
     
         7 . The method according to  claim 6  wherein the alkaline solution is a solution of 0.05 Normal sodium hydroxide having a pH of approximately 12.5.  
     
     
         8 . The method according to  claim 6  wherein the alkaline solution is first applied to the pre-crystallized PET bottle and then the solution of hydrogen peroxide is applied to the pre-crystallized PET bottle to react with the alkaline solution to generate active oxygen species and/or hydroxyl radicals.  
     
     
         9 . The method according to  claim 6  wherein the solution of hydrogen peroxide is first applied to the pre-crystallized PET bottle and the activation period is 30 seconds and then the alkaline solution is applied to the pre-crystallized PET bottle to reaction with the hydrogen peroxide to generate hydroxyl radicals.  
     
     
         10 . An apparatus for sterilizing and hot-filling containers, the apparatus comprising: 
 a conveyor mechanism for moving a plurality of containers through the apparatus;    a station for applying hydrogen peroxide to an interior surface and exterior surface of each of the plurality of containers;    a station for applying an activation agent to the interior surface and exterior surface of each of the plurality of containers, the activation agent reacting with the hydrogen peroxide to generate hydroxyl radicals; and    a station for hot-filling a fluid food product in each of the plurality of containers at a temperature ranging from 140° F. to 180° F.    
     
     
         11 . The apparatus according to  claim 10  further comprising a station for rinsing the interior surface and the exterior surface of each of the plurality of containers.  
     
     
         12 . The apparatus according to  claim 10  wherein each of the plurality of containers is inverted while conveyed along the conveyor means.  
     
     
         13 . The apparatus according to  claim 10  wherein the activation agent is a solution of sodium hydroxide.  
     
     
         14 . The apparatus according to  claim 10  wherein each of the plurality of containers is composed of a material selected from the group consisting of PET, PET derivative, polypropylene and polyethylene.  
     
     
         15 . The apparatus according to  claim 10  wherein each of the plurality of containers is composed of a polymer material.