A new innovation from MIT and the Singapore-MIT Alliance for Research and Technology (SMART) could help fight global food waste by extending the shelf life of fresh produce-without relying solely on refrigeration. Researchers have developed biodegradable silk microneedles that deliver tiny doses of melatonin directly into plants, keeping them fresh for days longer.
The scale of food waste is staggering:
More than 30% of the world’s food is lost after harvest, enough to feed over one billion people. While refrigeration is the most common preservation method, it requires costly infrastructure many regions cannot access. The MIT team’s approach offers a low-energy alternative that could complement existing cold storage systems. In their latest study, published in Nano letter, researchers tested the method on pak choy, a perishable leafy vegetable widely consumed in Asia. The team attached small patches of melatonin loaded microneedles to the base of freshly cut pak choy plants.
“Post-harvest waste is a huge issue, especially in emerging markets where cold chain infrastructure is limited”,said Sorojam Rajani, Co-senior author of the study. “Our method offers a potential solution that could be scaled for real world use”.
Further analysis revealed that melatonin increased antioxidant activity in the plants and triggered protective genetic responses, preserving chlorophyll and delaying yellowing. Unlike spraying or dipping, which showed no significant benefit in this trial, microneedle delivery ensures the hormones penetrate deep into the plant’s vascular system.
“This is the first time microneedles have been used to extend the shelf life of a fresh-cut crop”, said Benedetto Marelli, senior author and MIT associate professor. “It could make a real difference in reducing food waste and improving access to fresh produce.” The research was supposed by SMART and the National Research Foundation of Singapore, with hopes that the innovation will one day benefit farmers and consumers worldwide.
