Heating in food processing

Heat Processing
The development of the modern eating process started in France during the first decade of the 1800s by Nicholas Appert who preserved foods in sealed glass jars in boiling water

In 1819, William Underwood of the United States started the first canning factory in Baltimore.

But to preserve foods in boiling water took too long, requiring about 6 hours, so salt was added to the water bath which increased the boiling temperature, thereby shortening the processing time.

However salt corroded the cans so the next innovation was to heat in steam under pressure. The higher the pressure, the higher the temperature and the shorter the processing time.

These early pressure chambers evolved into the modern retort.
Heat Processing