The seeds of a solution for reducing food waste
Scientist, tree fruit breeder team up in major study of ways to prolong storage of fruit
There’s a Honeycrisp tree in Rich Feenstra’s Beamsville orchard that gives the impression it’s a bad apple.
Its branches are loaded with the darling of fall fruit, while its neighbours, standing soldierstraight beside it, have been picked clean. Yellow caution tape draped over its apple-filled limbs doesn’t help the tree’s oddball image either.
Feenstra didn’t skip over it because there was anything wrong with the near flawless fruit it offered, however. He and Jay Subramanian, a University of Guelph tree fruit breeder based in Vineland, are trying to determine just how good Honeycrisp apples can be when left on the tree weeks after most farmers call it quits on the season.
The tree and the row it’s part of at Feenstra’s Mountainview Orchards are being used in a multi-year study spearheaded by Subramanian to tackle one of the planet’s most pressing issues: food waste.
In the process, Subramanian has found a way to take the pressure off local farmers like Feenstra during harvest season while giving growers in developing nations more bargaining power when selling their crops.
Subramanian is working such magic with hexanal, a non-toxic chemical compound that naturally exists in plants to fend off insects and is also used commercially to flavour chewing gum. But when applied to fruit topically or in other ways, it can slow down ripening by weeks, extend shelf life and reduce spoilage and waste.
“I’m really excited by this product for a number of reasons,” Feenstra said. “If we can strengthen the fruit so it will store better and help harvest … that’s good for everyone.”
The study, which officially ended last March, was a global undertaking involving a team of scientists tapped to determine hexanal’s benefits on the world’s biggest and most valuable fruit crops: mangos, bananas, apples, citrus and grapes.
The Canadian International Food Security Research Fund, mandated to boost production, access and consumption of safe and nutritious food, contributed $4.2 million to the project, which was carried out in Canada, India, Sri Lanka, the Caribbean and Africa.
“Basically, they’re looking for high-impact work and most of these countries’ economies are driven by these fruits,” Subramanian said.
Here at home, Subramanian has trialed hexanal in Feenstra’s apple orchard the past two years to see how it performs locally to gain approval by the federal Pest Management Regulatory Agency (PMRA) for use in Canadian agriculture.
In the meantime, hexanal seems to be giving Feenstra a competitive edge over other growers.
Honeycrisp are vulnerable to a problem called bitter pit, which causes dark spots on the bright red and chartreuse apples. It isn’t dangerous, but bitter pit is unsightly, making affected apples unsellable to consumers hungry for perfect fruit.
The problem is bitter pit doesn’t show up until a few weeks after harvest, making it risky for farmers to store the apples longterm and stretch the supply for consumers.
Honeycrisp are also vulnerable to the mixed bag of weather Mother Nature often throws growers close to harvest. Those 30 C days that can happen in late September cause the apples to lose their colour and drop to the ground, turning a promising crop into compost.
So far, the Honeycrisp in Feenstra’s orchard sprayed with hexanal have been immune to such issues. Last year, he was able to keep treated fruit on trees until early November — weeks longer than usual.
They turned out to be some good apples when they were harvested, too. Their colour, crunch and juiciness stayed in tact, and they also fared well in storage.
Feenstra hopes for the same results with the fruit on that tree decked with caution tape.
“They tasted just like the day I picked them” he said of last year’s experiment. “There was way less bitter pit on the trees and also the apples were hanging better so I can leave them on the trees until the weather cools and they get their colour back.”
If hexanal is approved by the PMRA, Feenstra predicts more growers will plant Honeycrisp, and the uber-popular apple will be available longer in the supermarket.
“The industry wants to plant more Honeycrisp but right now, they don’t last into January or February,” Feenstra said. “This product has the potential to change that.”
Hexanal’s anti-aging properties were first discovered in a lab by Subramanian’s Guelph colleague, Gopinadhan Paliyath, about 12 years ago. Because of Subramanian’s connections in Niagara, he began testing hexanal for Paliyath in local cherry orchards in 2007.
Cherries treated with the concoction kept their bright red colour, and looked and tasted fresh weeks after harvest. In comparison, untreated fruit turned an unappetizing brownish-red and began to rot quickly.
Next, Subramanian tested hexanal on peaches and got similar results. Meanwhile, Paliyath tried it on tomatoes with great success.
“When it worked in those three crops, we knew we were on to something,” Subramanian said.
He discovered just how powerful a tool hexanal could be for farmers globally once he received food security research funding.
Mango farmers in India who tested hexanal for the study had greater leverage with middlemen who buy their harvests. In the past, growers would have been pressured into lowball prices for their crops, which perished quickly. Hexanal buys them time to shop around for better returns with their fruit staying fresh in the meantime.
“It gives power to farmers because it extends the life of a crop. So if Agent A is putting pressure on them, the farmer can go to Agent B now and get a better price,” Subramanian said.
He and Paliyath were also invited to bring hexanal to mango farmers in Tanzania after Jakaya Kikwete, then president of Tanzania, received an honorary degree from Guelph in 2013. The hope is it will open bigger export markets for farmers there.
“They have an export market, but it’s very small. Most produce is grown in rural areas and takes a long time to get to market,” Subramanian explained. “So if they export on a larger scale, the economy obviously gets better.”
The world, he added, has been missing out on many delicious tropical fruits, particularly different varieties of mangos and bananas, grown in developing nations lacking technology to get their crops to international markets.
Widespread use of hexanal would keep fruit fresh long enough to withstand shipment to far-flung nations where immigrants are hungry for a taste of home and curious shoppers want something different.
In Trinidad, hexanal has created a market for limes that cruise ships use in cocktail programs.
“Trinidad grows these limes, but the issue is they turn yellow and cruise lines don’t want them. But when they use (hexanal), they stay green and fresh for a week longer than usual and that’s enough for these cruise lines to use them,” Subramanian said.
There are plans to develop cheaper alternatives to sprays, including hexanal-emitting packets to place in fruit storage bins, and stickers to put on harvested fruit, ensuring farmers in poorer rural communities can afford to use the chemical that Subramanian hopes will also be approved for use in organic farming, too.
Closer to home, hexanal use means fewer mealy peaches and apples, and a less stressful harvest season for Feenstra.
“I’m hoping this gets approved sooner than later,” Feenstra said. “I’m really excited by what it’s doing.”