Retort Processing Technology


TechnologyHere you can see the photos of retorted Baked Beans produced by two different companies.One product was produced perfectly maintaining all the food qualities as compared to its fresh equivalence where as the other was badly processed and lost most of the basic food qualities.The company which produced the good food shown below produce about 5 million cans per day where as the other company hardly produce 5,000 cans per day. 

This indicates the importance of the application of proper retort processing technology in the production of retort processed food


Actually speaking, there is NO per-defined specific technology for processing any specific products. But there are good guidelines for processing the food in different types of containers in different types of retorts. These guidelines are being developed by expert food technologists across the world since more than 90 years.

The processor can modify the basic available technology as per the available resources like type of retorts, type of packing materials, type of recipes etc. and develop in house processing technology to produce high quality retort food.


The processing technology needs to be modified when the processor changes the container from cans to pouches It again differs when the containers are changed to Plastic Trays or glass bottles.

Similarly the procedure for the products processed in steam retort differs from Steam Air Retort. It again changes if the processor use water immersion retort or water spray retorts. He needs to modify when he changes to Rotary or Shaking Retort.

For example, tomato products needs sterilization at less than 100 deg C ( Pasteurization) where as Tomato Puree or Soup needs sterilization at high temperature because tomato is medium acid product where as tomato puree or soup are low acid foods.

So the processing technology needs to be defined based on type of products, type of containers and type of retorts used.

The food is first prepared, even raw or semi-cooked, and then sealed into the container ( it could be cans, pouches, plastic trays, bottles etc). The sealed container is then heated to 240-250°F (116-121°C) for several minutes under high pressure, inside retort or autoclave machine. The food inside is cooked, similar to pressure cooking. This process reliably kills all commonly occurring microorganisms (particularly Clostridium botulinum), preventing it from spoiling.

The sealing of the container before sterilization is to prevent entry of further bacteria into the food. The heating under pressure is to kill all the bacteria and its spores present in the food. So the sterilized food will be totally free of any kind of bacteria ( as long as it is perfectly in sealed condition) and will be safe for a very long time, depending on the type of container used.

There are equipment which help the processor to study in detail about the cooking and sterilization effects of the products during processing, behaviour of the containers and products during the processing, estimate the cooking damage occurring on the products during the processing, complete documentation of each steps in the development etc.

In this way, the processor can make use of such equipment / systems to develop and improve the basic technology based on their requirements keeping the critical steps in the basic technology unaltered.