Canning and Fish Packaging Technology

Unit 2 - Historical developments in canning technology

2.3.Progress in thermal processing
In Appert’s process, the maximum temperature reached was 1000C. Hence, for some foods, a long time heat process extending upto 3 to 4 hours was required to prevent spoilage. In order to reduce the heat processing time, temperature more than 1000C was required. Fostier in 1839 used common salt or other salt solutions to elevate the boiling point and hence the temperature of processing. However, use of salts caused corrosion of vessels. In 1843, Winslow and Reymond Chaneliar Appert used steam under pressure to get elevated temperatures and reducing the processing time. In 1874, Scheiner, produced steam separately and used for heat processing of cans. At present, the same process is being used in industry for heat processing of canned foods.

In the beginning of 20th century, research was conducted to assess the heat resistance of microorganisms, heat penetration into the cans and thermal process calculation. In this field the contribution of Bigelow, Ball, Olson, Stevens and Stumbo are noteworthy. Using the principles of thermal processing, High Temperature Short Time (HTST) process and aseptic packaging have been developed.