Patent ID: 7008659

Claim:
An inert gas-filled cooking method for sterilizing food at a food sterilization temperature, comprising the steps of: preliminarily processing food by heating which does not cook the food; filling the preliminarily processed food which is prepared but not cooked into retort pouches and hermetically sealing the retort pouches under an inert gas atmosphere; loading the food retort pouches into a sterilization tank; pressurizing the sterilization tank having the food retort pouches loaded therein at a predetermined pressure value by means of a pneumatic conduit and an analog pressure regulating valve; raising the temperature of the food in the food retort pouches to a first predetermined temperature value below the sterilization temperature of the food in the food retort pouches by reheating a heated steam supplied to the primary of a heat exchanger by means of a steam superheater causing a rapid increase in the temperature of heated water flowing in the secondary of the heat exchanger and subsequently into the sterilization tank where the heated water is applied to the food retort pouches; maintaining the temperature of the food in the food retort pouches at said first predetermined temperature value by continuing the application of the heated water to the food retort pouches; raising the temperature of the food in the food retort pouches from said first predetermined temperature value to a second predetermined temperature value which corresponds to the sterilization temperature of the food in the food retort pouches, by increasing the temperature of the heated water supplied to the sterilization tank where the heated water is applied to the food retort pouches; maintaining the second predetermined food sterilization temperature on the food in the food retort pouches for a predetermined time by continuing the application of heated water at said second predetermined temperature value which is less than the time at which the first predetermined temperature is maintained; wherein said predetermined pressure value is maintained during the maintenance of said first and second predetermined temperature values; and cooling the food retort pouches from said second predetermined food sterilization temperature by applying cooling water instead of hot water on the food retort pouches.