Researchers unlock post-harvest technology to cut mango waste and improve cold storage viability

Dipping mangoes in ozonated water (aqueous ozonation) for ten minutes before storing can extend the cold storage life by up to two weeks, according to Australia’s Edith Cowan University research.

The findings can bolster food waste reduction approaches and trade practices, given a global rise in the consumption of fruits and vegetables, the researchers note.

The study, led by ECU School of Science lecturer Dr. Mekhala Vithana, notes that the method also recorded significantly lower occurrences of chilling injury.

“Increasing storage life of mangoes is incredibly important for both growers and traders, as it reduces food loss during storage and offers a longer market window,” says Vithana.

Mango storage challenges

Mango production has increased in the last few years owing to changing consumer habits. However, substantial stock is wasted along the supply chain due to rapid ripening and excessive perishability.

“It is estimated that about 20% of the total Australian mango production is lost or wasted, and horticultural produce is responsible for about 50% of the total food waste in Australia,” says Vithana.

This food loss is about 3% of Australia’s greenhouse gas emissions annually.

“Therefore, exploring eco-friendly and cost-effective technologies to minimize post-harvest losses of mangoes is important.”

Mangoes are usually picked upon reaching the mature green stage and then stored at 13 degrees Celsius for up to two weeks. However, the researchers highlight that this temperature is not cold enough for extended storage.

“Being a tropical fruit, unripe mangoes should not be stored below 12.5 degrees due to their high sensitivity to cold temperatures. Prolonged storage of mango below this temperature causes a physiological disorder known as chilling injury, which damages the fruit skin and leads to decreased marketability and significant food waste,” says Vithana.

“Therefore, susceptibility to chilling injury is the key limitation for exploiting cold storage technology to its maximum capacity for lengthening the storage life of mangoes.”

The technology

The study, published in Springer Nature, was conducted on Australia’s most commonly grown variety of mango, Kensington Pride, and tested aqueous ozonation technology to improve its resilience to chilly temperatures during storage.

“Aqueous ozonation extends the storage and shelf life of these mangoes up to 28 days, with 40% less chilling injury than untreated mangoes,” Vithana notes. “It seems to be a highly feasible technology for improving chilling tolerance and fruit quality.”

She says ozonation can be controlled on-site, is economical, and considered safe for workers at a threshold level due to its faster breakdown into oxygen.

“Aqueous ozonation is bubbling ozone into water through an ozone generator. Ozone is a compound widely used to sanitize fruits and vegetables on a commercial scale.”

“The ozonation can be combined with the hydrocooling step after quarantine heat treatment in export mangoes or separately as a sanitization step just after harvesting, depending upon the grower’s convenience, but this needs further optimization under commercial settings,” Vithana adds.

The researchers plan to extend testing to other varieties of mangoes to gauge responsiveness and further reduce chilling injury for longer cold storage times.