Food scientist Yanyun Zhao and a team of international scientists discovered a substance in blueberry leaves that can be added to plant coatings, adding antioxidants and shelf life.

"Normally, blueberry leaves fall to the ground as waste," said Zhao, a food science and technology professor at Oregon State University’s College of Agricultural Sciences. “We've discovered a use that can change how the berries are stored, sold, as well as increasing their nutritional value.”

To create the coatings, researchers mixed these phenolic extracts with chitosan, a natural preservative that comes from crustacean shells. Zhao, along with scientists in China, tested coatings made from leaves that were picked at different stages of berry maturity, and leaf extracts were formulated into five different coating treatments based on varying levels of phenols.

Blueberries were dipped in the liquid coating and then dried at room temperature to form dried coatings. "Nozzles can also spray the coatings on the surface of the berries as they pass by on a conveyor belt,” according to Zhao.

“Coating the blueberries will add to their cost,” Zhao said, noting that how much more they will be worth is still in question.

Blueberry leaves, which have been used as an herbal remedy, contain high levels of antioxidant phenolics,­ chemical compounds, which protect against fungi and bacteria.

For more information, visit www.extension.oregonstate.edu/news/release/2014/06/blueberries-coated-leaf-extracts-have-longer-shelf-life