Researchers at the Massachusetts Institute of Technology (MIT) have devised a novel technique aimed at extending the shelf life of produce. The approach involves using silk microneedles to deliver melatonin into plant tissues. Detailed findings are published in the journal Nano Letters.
The United Nations reports that more than 30% of food is lost post-harvest globally, amounting to a volume that could feed over a billion individuals. Existing cooling methods are energy-intensive and costly, and often inaccessible in certain regions. This new technology could reduce food losses without large-scale refrigeration.
At the heart of the method are tiny sticker arrays composed of natural silk. Each array includes hundreds of microneedles less than a millimeter in length. These needles penetrate the skin of fruits and vegetables without causing damage or stress to the plants. They deliver melatonin, an antioxidant known for regulating plant protective mechanisms and slowing aging processes, directly to plant cells.
In experiments with bok choy, a vegetable with high perishability, the treated specimens lasted four days longer at room temperature and ten days longer in refrigerated conditions compared to untreated samples. Parameters such as weight, color saturation, and chlorophyll content remained stable longer in the treated group.
"We have demonstrated the safety and effectiveness of melatonin delivery using biodegradable silk microneedles," said Professor Jonathan Kim, the research leader. "In the future, such patches could be applied automatically during direct crop processing - for example, using agricultural drones or machine manipulators."
Future research will focus on examining other phytohormones and their impact on various crops. The team also aims to develop technology for the large-scale production of microneedles for commercial use. This innovation could play a role in decreasing global food losses and enhancing food security without incurring additional energy costs.
Source: Baku