Canning

Canning is a way to keep food safe to eat for a long time. It works by cooking the food and putting it into a container that is sealed tightly, like jars or cans. This helps stop bad things from spoiling the food.

Canned food can stay good for one to five years, and in some special cases, even longer.

A long time ago, in 1974, people tested food that had been canned in 1865 from a steamboat called the Bertrand that sank in the Missouri River. Even though the food looked and smelled different and had lost some vitamins, it was still safe to eat. This shows how well canning can keep food for many years.

food preservation Mason jars steel and tin cans shelf life lentils Bertrand National Food Processors Association

History and development

See also: Mason jar

The Dutch were the first to tin food, carrying salmon in tin-plated iron boxes in 1772.

Before the Napoleonic Wars, the French government offered a prize for a way to keep food fresh for the Grande Armée. In 1809, Nicolas Appert, a French food maker, found that food cooked in jars stayed fresh if the jars were sealed well. He won the prize in 1810. Later, Louis Pasteur explained why food spoiled and created pasteurization.

The Grande Armée tried using canned food, but it was hard to make enough. After the wars, other countries started using canning too.

In the United Kingdom, Philippe de Girard used a merchant named Peter Durand to patent his idea in 1810. Bryan Donkin and John Hall bought the patent and made sealed cans from iron. Only the British Army and Royal Navy could afford them at first. By 1817, they sold a lot of canned meat.

During World War I, armies needed food that wouldn’t spoil. Canned food became important. Soldiers ate canned pork and beans, bully beef, and stews. Later, better meals like coq au vin, beef bourguignon, and canned spaghetti were made. After the war, companies improved their products for everyone to buy.

Methods

Early cans were made of glass, but they were heavy and broke easily. Later, people started using metal cans, which are cheaper and stronger. Today, most cans are made from tin-coated steel.

At first, people didn’t have can openers, so they had to use knives or other tools to open cans. Now, we have special tools just for opening cans.

Glass jars are still used sometimes, especially for foods people make at home.

Microbial control

To keep food from spoiling, people use many methods. They heat the food to high temperatures, cool it quickly, or use natural ingredients that stop bad things from growing. Some foods are dried or put in strong saltwater.

One big danger is a tiny germ called Clostridium botulinum, which can make people very sick. To be safe, most foods like vegetables, meat, and seafood need to be canned using high heat in a special machine called a pressure canner. Fruits and pickles can be canned using just boiling water because they are naturally sour.

Sealing: double seams

Main article: Double seam

In 1888, a new way to seal cans was invented. This method creates a tight seal that keeps air and germs out. Cans made this way are called Sanitary Cans. The top and bottom of the can are folded and pressed together to make a strong, airtight seal. This way, the food stays fresh and safe to eat.

Nutritional value

Canning is a way to keep food safe to eat for a long time. Canned fruits and vegetables have the same good things, like dietary fiber and vitamins, as fresh or frozen foods. Sometimes, canned foods even have more of these good things. For example, canned tomatoes have more lycopene, which helps us stay healthy. Because of this, canned meat and vegetables are often kept ready for use during emergencies.

Potential hazards

See also: Packaging and labeling and Food safety

Long ago, canning food sometimes happened in small factories that were not always clean. Without refrigerators or strict rules, some cans could have unsafe stuff in them.

Salt is used in canning to keep food from spoiling, but it can also make people eat too much salt. Too much salt can cause health problems like high blood pressure. Some canned foods now have less salt or no salt. Rinsing canned vegetables well can help lower the salt amount because a lot of the salt is in the liquid, not the food.

Further information: Botulism § Prevention

Sometimes, canned food that wasn’t heated enough can become unsafe to eat. This can let a special kind of germ grow and make a poison. This poison is very dangerous and can make people very sick. Doctors take any possible cases very seriously to keep others safe.

Canning and economic recession

Further information: Recession

When money is hard to come by, like during tough economic times, many people choose canned foods. This helps them save money because they can stay home instead of spending on meals out or entertainment. Some people also keep extra canned food at home, just in case.

In February 2009, when the economy was struggling, sales of canning supplies rose by 11.5% in the United States. Certain places in the US even offer special centers where people can learn how to can food or rent a kitchen to do it themselves.