Canning and Fish Packaging Technology

Unit 4 - Thermal process for canned foods

4.10.Aseptic Packaging
The traditional method of sterilization involves filling the food into its containers which is then hermetically sealed before heat treatment in the retort. The continuous flow system combined with aseptic filling was developed from the retort system because increasing the temperatures in combination with shorter holding time has the same lethal effect on microorganisms while reducing the adverse effects of other possible chemical reactions on the food. Moreover in a continuous flow process, the product temperature can be raised and lowered more rapidly than in batch process. Hence the time distribution for several parts of the food system will be more even.

Aseptic packaging involves placing a sterile product into a sterile package within a sterile environment and sealing them air tight (hermetically sealed). The pack must prevent subsequent re-infection of the product. Aseptic packaging linked with U.H.T (Ultra heat treated) processing offers advantages, over sterilizations in the container, of reduced heat denaturation, reduced energy cost for sterilization and opportunity to use cheaper containers. In addition, rapid heat transfer rates are achieved by passing the product through a plate or other specially designed heat exchangers.