Melatonin presents promising solution for reducing fresh produce postharvest losses

20 Jul 2023 --- As food security continues to be an escalating global concern, experts are pointing to melatonin’s potential for extending the shelf life of fruits and vegetables and minimizing losses between harvest and consumption. Losses that experts say are the equivalent of US$400 billion annually, as well as 8-10% of global greenhouse gas emissions.

Melatonin, a hormone naturally present in plants, has been linked to various physiological processes, including stress resistance and growth regulation. Researchers have found that the common sleep aid ingredient could help prevent chilling injury – a common postharvest problem that occurs when plants are stored at temperatures below 0°C.

“Fruit and vegetables are not only challenging to grow, preserving them is immensely difficult and this is a crisis affecting nations all over the world, so we need to find the solution to keep producing food from the Earth in a sustainable way,” says lead researcher and professor at Edith Cowan University, Dr. Zora Singh explained.

“Melatonin is a safe alternative to hazardous chemical treatments, without any adverse effects on the consumer’s health.”

Plague of food loss
The study, published in Food Reviews International, highlights that up to 44% of fresh horticultural produce is lost postharvest every year. This figure reflects the pressing need for innovative solutions to preserve our food supply and address food security challenges.

Factors such as shrinking agricultural land, water scarcity, climate change and soil degradation further exacerbate the problem and ensuring the availability of nutritious and fresh food continues to be a growing challenge.

The sleep aid could help preserve fruits and produce and increase food security.Chilling injury significantly contributes to produce losses. Moreover, the researchers reveal that chilling injury poses a significant threat to the quality and longevity of fresh produce, particularly for tropical and subtropical fruits and vegetables.

“The average storage temperature for subtropical fruits and vegetables usually ranges from 4–8°C while 10–20°C is the optimum temperature to avoid chilling injury in tropical horticultural produce.”

“You will often see abnormal ripening, sunken spots, pitting, hardening of flesh and browning of peel and pulp in cold-stored fruits, while browning of tissues, translucency and water-soaked lesions in the vegetables – that is what we call chilling injury,” Singh underscores.

Implications for global food security
The highly perishable nature of produce puts it at the greatest risk of spoilage during transportation and storage and notes that berries, bananas and many other tropical and subtropical fruits can only be refrigerated for 7 to 12 days.

“When it comes to grains and other produce for harvest, they are more resilient than fresh horticultural produce,” he adds.

The study suggests that melatonin application may hold the key to preventing or reducing the detrimental effects of chilling injury and the ECU team believes that harnessing melatonin’s properties could revolutionize the way fresh horticultural produce is stored and preserved.

The researchers add that addressing these postharvest losses is crucial for ensuring food security on a global scale. By adopting innovative methods to extend shelf life, they believe it is possible to reduce waste and enhance the availability of nutritious food.

Edited by William Bradford Nichols