AUTOCLAVE STERILIZATION PROCESS

PURPOSE:To carry out autoclave sterilization treatment of a retort food, etc., especially a gas-containing packaged food, in high yield while minimizing the volume change of the package, by controlling the pressure in a sterilization tank according to the temperature change in the tank. CONSTITUTION:A packaged material such as gas-containing packaged material is put into a sterilization tank 1 and sterilized under high temperature and pressure condition by raising the temperature in the sterilization tank. In the above process, a treating timetemperature program is prepared preferably before hand, the temperature in the sterilization tank 1 is measured by a temperature sensor 31 and a pressure necessary to keep the volume of the packaged material at a constant level is calculated from the measured result by a temperature- pressure converter 33. The calculated pressure value is compared with the pressure in the sterilization tank 1 measured by a pressure sensor 32 and the valve V13 of an exhaustion pipe 5c or a valve V14 of a feeding pipe 5d is operated by the pressure difference to approach the pressure in the sterilization tank 1 to the calculated pressure.