A blueberry leaf extract helps prolong the shelf life of berries while adding an antioxidant.

Researchers from Oregon State University and China found a substance in blueberries helped delay decay and retain water, according to a news release.

The natural coatings allow fresh blueberries to be washed and prepared as ready-to-eat, whereas most blueberries in stores are unwashed to retain the natural protective waxy coating on the fruit.

Blueberry leaves contain natural antioxidant phenolics—chemical compounds that protect against fungi and bacteria.

To create the coatings, the researchers combined the penolic extracts with chitosan, a natural preservative from crustacean shells.

Resarchers included Yanhun Zhao, an OSU food scientist, and Yun Deng at Shanghai Jiao Tong University.