Fruits and vegetables in a refrigerated section of a supermarket in Entebbe, Central Region, Uganda. Camille Delbos / The art in all of us / Corbis via Getty Images
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The natural hormone melatonin, known to aid sleep, has been shown to have another unrelated benefit: it can prolong the freshness of fruits and vegetables.
When fruits and vegetables are transported in refrigerated trucks or stored at temperatures that are too cold, they can “cold injury“, reports Food Ingredients First. Researchers recently discovered that melatonin can prevent this common post-harvest problem.
Horticultural scientists from Edith Cowan University (ECU) have spent the last year compiling research from around the world on melatonin‘s to keep fruits and vegetables fresh longer, according to a press release from ECU.
“You will often see abnormal ripening, sunken spots, pitting, hardening of the flesh, and browning of the skin and pulp in cold-stored fruit, while tissue browning, translucency and water– vegetable soaked lesions, that’s what we call a cold sore,” said Zora Singh, Horticultural Science Foundation Professor at ECU’s School of Science and principal investigator of the studyin the press release.
The study, “An overview of the role of melatonin in alleviating cold injury and maintaining the quality of cold-stored fruits and vegetables,” was published in the journal International food critics.
According to Singh, 44% of fresh produce spoils between harvest and consumption, with cold injuries being a major cause.
Berries can be stored in the fridge for a week to 12 days, while fruits like apples can stay fresh for up to nine months. Fruits that grow in tropical and subtropical climates are most at risk of cold injury.
“The average storage temperature of subtropical fruits and vegetables generally ranges from 4-8°C, while 10-20°C is the optimum temperature to avoid chilling damage in tropical horticultural produce,” Singh said.
Singh and the research team said melatonin reduces or prevents the effects of cold injury on fruits and vegetables, and can be used instead of chemicals.
“Melatonin is a natural sleep hormone in living organisms, and it is also useful in reducing cold injury symptoms and membrane leaks by maintaining higher levels of antioxidants and freshness of horticultural produce,” researcher and Ph.D. student Shoaib Shah explained in the press release. “Melatonin is a safe alternative to dangerous chemical treatments, with no adverse health effects for consumers.”
Each year, approximately $400 billion of food, or 13.2%, is lost from harvest to market, while 17% of food is wasted by the restaurant industry, retail and households. food waste and loss are responsible for about eight to 10 percent of greenhouse gas emissions global.
“When it comes to grains and other crops, they are tougher than fresh horticultural produce,” Singh said in the press release. “Fruits and vegetables are not only difficult to grow, their conservation is extremely difficult and it is a crisis affecting nations around the world, so we must find the solution to continue to produce food from the earth in a sustainable way.