Food preservation: a never ending story

Prolonging food life has always been a crucial challenge giving rise to many inventions and innovation processes.

When Andy Warhol painted Campbell’s soup cans in 1962, he had been inspired by popular culture and was representing the success of canned food. In fact he was depicting one of the most innovative ways to preserve food at that time.

Humans started preserving food a long time ago, when they discovered that some processes could make food last for longer without getting spoiled or rancid. Drying, salting, smoking, freezing and heating represent some examples.
Drying

When cooking spaghetti, we don’t usually think of it as dried food. Drying is a crucial step in the pasta production process, where humidity, air flow and temperature are carefully controlled.

Arabs, not Italians, were the first to treat pasta by drying it, so they could eat the product any time during their desert wanderings. The first historical records of dried pasta production date back to the 11th century in Sicily, a southern Italian region deeply influenced by Arab culture at that time.
Smoking

After discovering that meat cooked with fire was much more edible and tasty, humans realised that smoking could preserve foods from perishing, due to deposits of certain substances present in the smoke.

Oak and beech are the most used wood types for smoking. When burning, they generate antioxidant and antimicrobial compounds such as phenols and carboxylic acids. The smoking process can take place at a temperature below 24°C (“cold smoking”) or around 70°C (“hot smoking”).

Recently, the high costs and timing associated with traditional smoking along with concerns over phenols and other carcinogens have favoured the introduction of liquid smoking. This method consists of adding a cold aroma or injecting liquid smoke into the meat, thus not diminishing the bacterial load and therefore lowering the shelf life.

Canning

Canning is a method which extends a food’s shelf life typically from one to five years, or even more. The food is processed and sealed in an airtight jar or can and then sterilised by heating to a temperature that destroys microorganisms and inactivates enzymes. Heating and later cooling form a vacuum seal which prevents other microorganisms from recontaminating the food within the jar or can.

This method goes back to 1795 when Napoleon offered a prize to anyone who could invent a way of preserving food for his army and navy. In 1809, Nicolas Appert, a French confectioner and brewer, won it after discovering that if food was heated and then sealed in glass jars, it would not spoil.

Based on Appert's methods, Peter Durand, an English merchant, introduced tin cans in 1810. The reason why food didn’t spoil was unknown at that time. Fifty years later Louis Pasteur demonstrated the role of microbes in food spoilage.

Pasteurisation

Pasteurisation was invented by the French chemist Louis Pasteur in 1862. At the time, producers of French wine, which was being exported throughout Europe, were trying to find ways to preserve their precious beverage. Half of the wine had usually spoiled after a week or so.

After discovering microbes, Pasteur wanted to find a way to kill them without changing the taste of the wine. Boiling was not a solution. However, he did find a process whereby the wine could be heated to about 60°C for 10 minutes without any adverse effects.

Wine pasteurisation was only used for 10 years, until Pasteur discovered that if the wine barrels were cleaned with sulphur once a year, microbes would be kept away.

Beer pasteurisation followed and, many years after Pasteur’s death, the process was used to kill the pathogen microbes in food and drink such as milk, juice, and canned food.

Source: http://cordis.europa.eu/news/rcn/140575_en.html?isPermaLink=true?WT.mc_i...