Leafy greens decay rapidly, but a new technology developed by Dr Rivka Elbaum can extend shelf life by delaying senescence. The simple and cost-effective treatment involves dipping the leaves into a solution. The solution is a permitted food additive and may even have beneficial effects on human health.
http://www.timesofisrael.com/new-solution-to-keep-veggies-fresh-for-a-month-sans-fridge/
On the left, a pepper and lettuce leaf treated with the new solution after a week without refrigeration; on the right, untreated produce (Photo credit; Courtesy)