Autoclave Brief Introduction
In the simplest terms, autoclave is a closed, pressurized heater that heats the food sealed in the container. For foods that require commercial aseptic sterilization in a sealed package, a variety of different sterilization pot systems can be used.
The autoclave system has some of the same characteristics:
-- Autoclave system is pressurized and the transfer temperature is much higher than boiling water.
-- Autoclave system uses a medium (called a heating medium or a sterilizing medium) as a means of transferring heat to the product. The medium used in the pot includes pure steam, hot water (the container is completely submerged in water, or water spray) and a steam/air mixture.
-- Some autoclave systems use overpressure during sterilization and cooling to maintain container integrity and balance against the pressure inside the pot. This is necessary because some packaging containers have limited tolerance to internal pressure. Some examples of overpressure sterilization containers are semi-rigid plastic containers with heat-sealed or bimetallic seamed can ends, soft bag bags, metal plates, cardboard containers, and glass cans. The term "overpressure" refers to the pressure applied to a retort that exceeds the pressure applied by the heating medium at a given temperature. In autoclave, the pressure at 250 °F is about 15 psig, and any pressure applied to the sterilizer that exceeds the 15 psig is referred to as overpressure. An overpressure system, such as a 25-35 psig sterilization system, can be operated at higher temperatures.
-- The operation of autoclave must be appropriate to ensure that the container is sterilized to achieve commercial sterility.