Every year, the world wastes about one-third of all food produced for human consumption, a great amount of which results from inadequate storage and processing facilities for post-harvest produce. Developing technologies that help keep food fresh for longer is one of the most effective ways to save perfectly good food from ending up in the bin.
Scientists at the National University of Singapore have recently developed exactly that by turning discarded pineapple leaves into an eco-aerogel which can be used to keep fruits and vegetables for a longer period and, as an added bonus, could also help filter out toxic chemicals from wastewater.
“These eco-aerogels made from pineapple leaf fibers are very versatile,” explains Professor Duong Hai-Min, leader of the research team. “They are effective as oil absorbents and for heat and sound insulation. We have also demonstrated their potential applications in food preservation and wastewater treatment. This is a big step towards sustainable agriculture and waste management, and provides an additional source of income for farmers.”
The researchers developed the aerogel by shredding and blending the pineapple leaf fibers in the water while adding small amounts of non-toxic chemicals to the mixture. The concoction is then aged, frozen, and freeze-dried to create an aerogel, which is then treated with activated carbon. This last step is especially important for the material’s ability to preserve food as it enables the aerogel to absorb ethylene, the gas that drives the ripening of fruits and vegetables.
Since the aerogel is non-toxic, biodegradable, and can be disposed of without causing pollution, adding this eco-material together with food in packaging could extend the lifespan of fast-ripening produce by as long as two weeks.
“In our lab experiments, eco-aerogels modified with activated carbon can delay the rotting process by at least 14 days. The modified eco-aerogel can absorb six times more ethylene than commercial potassium permanganate ethylene absorbents,” says study author Professor Phan-Thien.
And the benefits of the newly developed material go further than helping prevent food waste. According to the researchers, coating the aerogel with the chemical diethylenetriamine would enable them to turn the material into a filter and use it to remove nickel ions from wastewater with four times the efficiency of conventional solutions.