An inconvenient fruit

Finding that smooth, ripe, perfectly yellow banana on the grocery store shelf can be one of the small joys of the shopping experience. More often than not, though, they’re hard and green, or freckled and mushy: such is the fickle nature of one of the world’s most popular, and vexing, fruits. For companies and retailers looking to get them to consumers, managing a banana’s short window of ripeness is a challenge—one with increasingly high-tech solutions.

According to the Canadian Produce Marketing Association, bananas are the most popular fruit in the world: last year, we imported over 443 million kilograms of them, mostly from Central and South America. A tropical plant, banana trees (which, with their leafy trunk, are actually classified as “herbs”) can’t be grown here, and producing them commercially in a greenhouse would be far too expensive, says Jay Subramanian, a fruit tree specialist at the University of Guelph. Like apples and mangoes, but not grapes, bananas keep ripening once picked; they’re harvested when mature, but still green, and will be on store shelves about two weeks later. That’s when the clock really starts ticking.

Grocery store shoppers might look for bananas that are slightly green, especially if they’re destined to sit in the kitchen a day or two. But the fruit’s ripeness is doubly tricky to manage at points of sale where people buy a single banana, often at a healthy markup from the supermarket price, then eat it right away—a growing trend. Starbucks began selling single bananas at most of its Canadian locations in March; they’re being sold at convenience stores like 7-Eleven and the Ottawa-based chain Quickie Convenience Stores, too. A banana’s short shelf life is a “challenge,” says Norman Dickinson, Quickie’s director of sales and marketing, because customers seek out those that are “completely yellow.”

Companies are looking at ways to keep them yellow longer, thereby boosting sales at convenience stores, which, Del Monte Fresh Produce tells Maclean’s in an email, “have been reluctant to sell produce.” Del Monte has introduced a new plastic wrap, called Controlled Ripening Technology, that they say extends a banana’s “yellow life” for up to five days. (It can be used as a liner inside crates, or wrapped around single pieces of fruit.) Individually bagged Del Monte bananas are now being tried out at some 7-Eleven locations in the U.S., with plans to expand. Consumers can buy their own baggies, too: U.S.-based Bio-Fresh sells wrap that preserves shelf life by absorbing ethylene gas, a natural hormone that causes bananas to ripen, says developer Buki Schwartzman.

Along with ethylene, which is present in most of the produce we eat, the ripening process is fuelled by a banana’s own respiration (like us, they breathe in oxygen, and breathe out carbon dioxide). To extend shelf life, companies must artificially slow this down. Once picked, bananas are cooled to about 15 degrees and packed in shipping crates, some with liners designed to lower oxygen levels and boost carbon dioxide, stalling the fruit’s respiration. “It’s only in the last five years that big companies are doing this on a large scale,” says Jeffrey Brecht, a post-harvest researcher at the University of Florida.

As a banana matures, it pumps out more ethylene, which must be controlled. Cargo ships that carry bananas often have filters to scrub ethylene from the atmosphere; the fruit is also sometimes spritzed with a chemical compound to render it temporarily insensitive to it. Once bananas arrive at the warehouse, they’re zapped with ethylene to kick-start the ripening process again. Like other grocery stores including Loblaw’s, Metro has pressurized “ripening rooms” where bananas are warmed up, then exposed to ethylene gas, says quality assurance specialist Dan Bears. After they transition to green and yellow—a stage three on the banana’s seven-point colour scale—they’re shipped off to stores. (While Metro doesn’t treat any of its other produce, ripening rooms can also be used for tomatoes, avocados and others, says Bears. Metro’s Toronto warehouse has professionally trained ripeners on staff.)

Of course, there are some lower-tech ways to keep bananas yellow for longer. People looking to prevent “banana trauma” might consider investing in the Banana Guard, a hard plastic armour that sheaths the fruit. (Its Vancouver-based maker, Aberrant Designs Inc., sells Froot Guards that protect apples, pears and peaches, too.) New York’s Museum of Modern Art offers clear plastic “Banana Bunkers” in its gift store. Experts have their own advice. “Don’t ever put them in the fridge,” Brecht says. “It takes the aroma away, so they don’t taste as good.”

A uniformly yellow banana might be most appealing to North American consumers—but those who turn up their noses at a freckly brown fruit might ultimately be missing out. “People think when there’s a brown spot on it, the banana is not edible,” Subramanian says, adding that these spots are “a very soft fungus” just a few cells deep. Even with some freckles, “the fruit is completely edible,” he says, “and even a little more sweet.”