Introduction to canned food:
Canned foods are part of our daily lives and yet we tend to take them for granted. But have you ever wondered what sort of industry exists to provide you with some of your favourite foods? How a can is made? How canned food is processed? Or why we have canned foods anyway? The story is a fascinating one.
Preservation of food:
Throughout human history, food preservation has been essential to survival.
Fresh or raw food is perishable and becomes unfit to eat over a relatively short time as a result of decay caused by the multiplication of living, microscopic organisms including bacteria, yeasts, moulds and enzymes. Some of these micro-organisms are harmful if eaten and cause food poisoning.
Since the earliest times, mankind has looked for ways to prevent foods from perishing, while keeping them pleasant to eat.
Pre 18th Century:
· Traditional methods of preserving foods included sun drying, salting, smoking, freezing and pickling.
· The French emperor Napoleon Bonaparte offered a prize to anyone who could come up with a new way to preserve food, as traditional methods of preserving food didn’t keep it edible for long enough to reach France’s far-flung armies.
· The prize was won by Nicolas Appert, a confectioner, who discovered that heating food to high temperatures inside sealed glass jars stopped it from spoiling.
· It was then discovered that the process worked just as well with tinned iron canisters, which had the advantage of being lighter, easier to seal and less prone to damage during transportation and storage. The iron was coated with a fine layer of tin to stop it from rusting.
· Over half a century after Appert’s process was unveiled, scientists discovered why his process preserved food; the heat used in the canning process kills the micro-organisms which cause food to decay.
· Cans were mainly used by the army and navy until the 1920s.
· There was a need to identify a more efficient way of canning food. The first cans were expensive because they were made by hand.
· The production of cans became mechanised. A machine was developed to stamp out the can bodies, then to solder the can ends. It was then discovered that if food is heated under pressure, the heating and cooling times become shorter which improved the flavour, texture and nutritional value of the food.
· Canned food eventually lost its military image and became fully accepted as part of the national diet.
· Today’s sophisticated production lines can produce in excess of 1,500 cans a minute.
· Cans are now made in all sorts of different shapes and sizes, some with easy-open-ends or peelable foil.
· Today cans weigh over 30% less than those produced 20 years ago, using fewer raw materials, and are stronger and safer than ever.
· The processing of food in cans also continues to develop to enable food manufacturers to fill cans faster and handle the latest styles of metal cans and ends.
The food can has been around for over 200 years and because it is such a safe, strong and convenient form of packaging, it is likely to be around for another 200 years!