You go to a mall or a large store and you can see lines and lines of canned food items on their shelves.You may wonder as to why perishable food items that can get spoilt within a couple of days stay fresh for days together in these process food tin cans. To better understand how canning works and the underlying process behind it, we need to go a little back in history. Canning first of all is a process of enclosing sterilised food items in tightly sealed cans. Nicholas Appert of France was the person responsible for inventing this technique in 1809 in response to a call by his government to develop a method that could preserve food for long duration for military use.
Nicholas developed an ingenious method of food preservation. He heated the food and then transferred it into the jar after which the jar was tightly sealed so as to not allow any air to go inside. The method worked to perfection but Nicholas could not explain the reason as why didn’t the food spoil. It was fifty years later that Louis Pasteur was able to explain as to why the food kept inside the sealed container didn’t spoil. The logic, in fact, was pretty simple: the heat destroyed the microorganisms already present and the airtight jars ensured that no microorganisms entered the jar from outside.
In 1810 Peter Durand of England patented the use of tin-coated iron cans instead of bottles, and by 1820 he was supplying canned food to the Royal Navy in large quantities. This method of canning soon reached United States where it became immensely popular in a very short period of time. The country ultimately became the world leader in both automated canning processes and total can production. It was in the United States the optimum time-temperature heating requirement was established for sterilising canned foods.
Originally, cans consisted of a sheet of tin-plated iron that was rolled into a cylinder (known as the body), onto which the top and bottom were manually soldered. This form was replaced in the early 20th century by the modern sanitary, or open-top, can, whose constituent parts are joined by interlocking folds that are crimped, or pressed together.
It is important to note that majority of the modern tin cans are made up of 98.5 per cent sheet steel with a thin coating of tin. Reputable can manufacturers in India as well as the rest of the world produce these cans in large numbers through machine productions. And when we talk about food cans, it is also important to note that food items like vegetables, meat, dairy products, fruits, etc are stored in tin cans whereas beverages are stored in aluminium cans. Aluminium cans are lighter and also do not easily catch rust.
