This Saturday, the American Chemical Society celebrated Earth Day with a daylong event in Washington, D.C., designed to teach children the role of chemistry in preserving food, feeding people and sustaining the planet. A variety of games and experiments, including identifying starch-containing foods using a special pen and pulling iron from breakfast cereals with a strong magnet, illustrated chemistry’s connection to virtually everything we eat.
Fun and games aside, no lesson in eco-friendly eating is complete without a few words on food sustainability’s unsung hero — the endlessly recyclable can.
The chef-chemists who invented canned food
It wasn’t a scientist who developed the first canned food, but a chef. In 1795, the French government offered a prize of 12,000 francs to anyone who could figure out how to preserve food long enough so that it could reach soldiers fighting far from home.
In 1809, chef Nicolas Appert won the prize after figuring out that certain foods could be packed into airtight glass or metal containers, then heated to a temperature high enough to kill off any food-spoiling bacteria. Can openers hadn’t yet been invented, so soldiers used bayonets to open the cans.
Appert’s canning method didn’t stay secret for long. By 1812, the first canning facility had opened in New York. By the 1870s, the United States was the top producer of canned foods in the world.
A no-waste, healthy food source
There are now machines that can seal more than 2,000 cans per minute, but the basic chemistry behind canning hasn’t changed much in 200 years. Food is packed into sealed containers, then heated to destroy bacteria (although some vegetables are heated before being placed into cans, and some acidic foods need to be sterilized before packaging).
After the can is heated and sealed, the contents inside of it are safe to eat for years. “Manufacturers have a ‘use by’ date on the can, but you can still eat the food five or more years after that,” says Jeannie Nichols, the Senior Educator in Food Safety at Michigan State University. “That date is just a suggestion.”
To ensure that canned foods are at their peak regarding flavor, freshness and nutritional value when sealed into containers, many canning facilities are located near fields where fruit and vegetables are grown, or near fishing docks. One study found that certain canned foods, like pumpkins and tomatoes, contain more vitamins and other good stuff than their fresh counterparts.
That’s important because “sometimes grocery stores get fruits and vegetables from other countries,” Nichols says. “You don’t know how long they’ve been in transit, or what they’ve been treated with so they don’t spoil.”
Because canned foods can be stored so safely for so long, they account for a large percentage of the contents of most kitchen pantries. Food that is canned, after all, dramatically reduces waste.
Canned foods are inexpensive and recyclable
Canned food especially benefits those who can’t afford, or easily access, fresh fruits, vegetables and meats. A 2012 Michigan State University analysis found that 48 million Americans often worry that they’ll go to bed hungry. And 23.5 million people live in areas known as “food deserts” with little or no accessibility to fresh foods.
After scrutinizing more than 40 studies, the researchers concluded that canned fruits and vegetables are an excellent, and inexpensive, way for Americans to meet their daily nutritional needs.
There’s one last reason why honoring cans on Earth Day is appropriate. Steel and aluminum cans are 100 percent recyclable, meaning there’s no reason (besides people misunderstanding what can and can’t be recycled) for one to ever end up in a landfill.
The more cans we recycle, the more we protect natural resources and save energy. According to the Can Manufacturers Institute, recycling 1 ton of steel cans conserves 2,500 pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone.
So as summer nears, don’t forget that while you can certainly honor nature by buying and growing fresh produce, canned food benefits the environment and humanity, too