An innovative technology developed by Columbia PhytoTechnology and Washington State University assistant professor of food science Kerry Ringer preserves health-promoting compounds in dried blueberry powder

The development helps meet consumer demands for highly nutritious foods at the same time as addressing industry concerns about costs.

Called the radiant zone dryer, the technology as the subject of a study published recently in the Journal of Agriculture and Food Chemistry. The probe shows that dried blueberry products retain as many antioxidants and anthocyanins as liquid products.

"We focused our study on drying of blueberry puree, blueberry juice and blueberry extract supplied by Washington fruit processing companies," says Ringer.

It is well known that blueberries are health promoting. Rich in antioxidants and anthocyanins, consumption of blueberries is associated with improvement of ischemic stroke outcomes and antioxidant capacity in blood plasma after eating them.

In comparison to other berries, blueberries have higher antioxidant activity and anthocyanin content.

Blueberries, though, are a seasonal crop with a short shelf life as a fresh product. To meet consumer demand, fresh berries have to be either frozen or otherwise processed. Because maintaining frozen products is expensive, there is a growing interest in development a cost-efficient preservation method capable of minimizing degradation of anthocyanins in processed berry products such as powders.

The new technology customizes drying times and temperatures to get the best product at a reasonable cost, researchers claim. By using damaged fruit, the technology recovers profit from the loss columns of producers.

"This project demonstrated the development of value-added products that potentially bolster profit margins and the types and numbers of jobs in agriculture," says Ringer.