Method for heating and cooling sealed food product pouches

• US 5,281,426 A
• Filed: 01/25/1993
• Issued: 01/25/1994
• Est. Priority Date: 02/24/1992
• Status: Expired due to Fees

• Current Assignee: Marty Tucs
• Original Assignee: W R Grace & Company - CONN (Standard Industries Holdings, Inc.)
• Inventors: Pardo, Richard J.
• Primary Examiner(s): YEUNG, GEORGE CHAN PUI
• Application Number:
  US08/010,027
• Time in Patent Office: 365 Days
• Field of Search: 426/232, 426/233, 426/407, 426/412, 426/509, 426/523, 426/524, 99/330, 99/355, 99/367, 99/370, 99/470, 99/517
• US Class Current: 426/232
• CPC Class Codes: A23L 3/10 by heating materials in packages which are not progressively transported through the apparatus

Abstract

An automatic heating apparatus for uniformly cooking foods which rapidly cools the cooked foods to reduce spoilage. Food packages are placed on trays and the trays are inserted in a transportable rack. The rack is loaded into a cooking tank. A pump continuously circulates hot water through a conduit from a heat exchanger to the tank to cook the food and returns the water back to the heat exchanger. A control mechanism determines and controls the temperature of the water and monitors the temperature of the food to control the length of time the heated water is applied. After the food has been properly cooked and pasteurized, cold water is rapidly supplied to the tank to quickly cool the cooked products. The continuous circulation of water during the heating mode provides uniform cooking with precise temperature control and the circulation during the cooling mode provides for rapid cooling so as to reduce spoilage.

Claims

1. A method of preparing food products by a thermal process of cooking to at least the required pasteurization temperature and time and quickly cooling the cooked food products for subsequent chilled unfrozen storage as refrigerated products comprising the steps of:

placing a food product in a formed pouch made of a material having a low gas permeability;

vacuumizing and sealing the pouch;

placing a plurality of sealed pouches onto a transport rack;

inserting into at least one of the food product pouches a thermocouple which is connected to a temperature controller/recorder and programmable microprocessor so as to monitor, and therefore control, the entire thermal process;

placing the transport rack with the sealed pouches into an automatic heating and cooling apparatus for uniformly cooking foods and reducing spoilage of the finished refrigerated products which increases the shelf life of the cooked food product sealed within the pouches, comprising;

a tank for heating and cooling the food product sealed within the pouches to be placed in the tank;

rack means to hold the food product pouches in a separated condition when placed in the tank;

means to supply water to the tank;

a heat exchanger;

conduit means connecting the tank and the heat exchanger to circulate water from the tank to the heat exchanger and to return water from the heat exchanger to the tank;

pump means in said conduit means to continuously circulate water between the tank and the heat exchanger and back to the tank;

control means to determine and control the temperature of the water and the time heated water is applied to the tank to cook the food in the tank to the desired extent, and

means to quickly cool the cooked products to reduce spoilage;

cooking the food product sealed within the pouches in said heating and cooling apparatus by circulating water through the tank and heat exchanger until the required pasteurization temperature and time has been reached; and

quickly cooling the cooked food product inside the sealed pouches by direct contact with cooling water so as to prevent overcooking, the restrict microbial growth, to prevent autolytic changes in the food product sealed within the pouches, and to provide for longer shelf life at the refrigerated temperatures in the range of 38°

F. to 32°

F., said longer shelf life being due to the greater bacterial destruction in cooking and the restriction of bacterial growth during cooling and refrigerated storage.

2. A method according to claim 1, wherein the thermocouple is a hypodermic needle thermocouple which passes through a sealing pad and the pouch itself.

3. A method according to claim 1, wherein the pouch material is a composite multilayer structure with ethylene vinyl alcohol as a barrier layer.

4. A method according to claim 11, wherein the sealed food pouches are placed on reinforced wire trays and the trays are stacked into a transport rack.

5. A method according to claim 1, wherein the temperature of the circulating water for heating is maintained at the required pasteurization temperature with an extreme accuracy of about ±

0.2°

C.

6. A method according to claim 1, wherein the cooling step uses water cooled to a temperature in the range of about 38°

F. to 32°

F.

7. A method according to claim 1, wherein the amount of the cooking is determined by the programmable micro-processor using a F-Value general formula for various foods for bacteria destruction during the cooking step.

8. A method according to claim 7, wherein greater food safety is provided by using F-Values high enough to provide D-Values on the order of many types of heat resistant bacterial spores which are disease causing.

9. A method according to claim 8, wherein a reference temperature of not less than 82.2°

C. (180°

F.) and a Z-Value of 10 is used to provide an additional margin of safety.

10. A method according to claim 1 wherein the formed pouches contain individual food product servings in the range of about 4 to 6 ounces.

11. A method according to claim 1 wherein the formed pouches are production packages having a capacity of about 8.5 to pounds.

12. A method according to claim 11, wherein the cooking and cooling steps are monitored and controlled by the controller/recorder and programmable micro-processor which are connected to the thermocouple.