I was just going to put some leftovers inside the fridge last evening, when I wondered how the fridge had been invented.
Refrigeration is an essential food storage technique that is seen in almost every household. But have we ever stopped by the machine and given a thought to the process that seems to save our food from getting spoiled for long periods of time?
Come, let us delve a bit deeper and see what story emerges from the coils of a refrigerator.
Can you imagine living without a fridge? No, you might say. But then let me remind you that man did live without this modern day convenience for a very long time.
You will be surprised to know that the invention of the fridge was a long process — from the time it was first conceptualised and manufactured to the modern day avatar we are familiar with.
Pages from history tell us that the first known artificial refrigeration was demonstrated by a gentleman known as William Cullen at the University of Glasgow in 1748. However, he did not use it for any practical purpose. It was an American inventor called Oliver Evans who designed the first refrigeration machine, many years later in 1805.
After that came experiments by Jacob Perkins who in 1834 made a practical refrigerating machine.
Renowned physician John Gorrie made a machine based on the designs of Oliver Evans in 1844 to cool the air for his patients suffering from yellow fever.
It was in 1913 that refrigerators for home and domestic use were invented by Fred W Wolf of Indiana. William C Durent started the Fridgaire Company in 1918 to produce fridges on a mass scale. Soon the phenomenon, which was convenient and had gradually become automatic, gained worldwide success and Kelvinator and Electrolux were the two companies that commercialised it.
Today the machine that you see in your homes is based on a concept adapted from the experiments of Michael Farady. This involved compressing gas into a liquid which then absorbs heat.
Now what does that have to do with keeping the food from getting spoilt, you may ask.
To answer that question first let me point out something that I mentioned at the beginning.
Contrary to popular belief, the fridge does not save food from going bad, it just delays the process.
We know very well that food is organic and contains cells that grow and die. When you put something in the fridge, it cools the food to a temperature just above freezing. What happens now is that in this cooled atmosphere, the entire process of the cells dying and regenerating becomes slow.
By restricting the growth process, the refrigerator makes a lower amount of food, that is the cells, available to the bacteria to attack and spoil.
Hence the bacteria does not grow at a rapid pace. Cold air also wrings out humidity, taking away a suitable atmosphere for fungus — the other organism that threatens our food — to grow as well.
In a freezer, things are worse for the bacteria and the fungi as they die rather than retardation setting in, because of the hostile environment.
So now you can see how the basic principle of food preservation is used by science to help make our lives easier.