Perspectives Online

A Bountiful Berry. College researchers see juicy new markets and anticancer benefits in the state's abundant blueberries. By Natalie Hampton

Dr. Leon Boyd (opposite, left) and Dr. Dan Carroll, professors in the College's Department of Food Science, are exploring processes that can increase the antioxidant value of the juice of blueberries, as well as other uses for blueberries, to create new markets for the fruit. Photo by Daniel Kim
Dr. Leon Boyd (left) and Dr. Dan Carroll, professors in the College's Department of Food Science, are exploring processes that can increase the antioxidant value of the juice of blueberries, as well as other uses for blueberries, to create new markets for the fruit.
(Photo by Daniel Kim)
Blueberries, for most of us, call to mind a sweet summer fruit, widely grown in North Carolina. For Leon Boyd, professor of food science in N.C. State’s College of Agriculture and Life Sciences, blueberries may hold promise as a way to turn average fruit juices into cancer-fighting elixirs.

Boyd believes that North Carolina, as the nation’s fifth largest producer of blueberries, has a great potential for blending blueberry juice to other fruit juices. Juice products would provide another market for the 13 million pounds of blueberries the state produces each year, as well as the added benefit of blueberries’ antioxidants.

Blueberries, and other fruits and vegetables, are high in antioxidants that help protect cells from the damaging effects of oxygen free radicals created by our own bodies, as well as from other sources, including environmental pollution.

Free radicals can contribute to degenerative diseases, including cancer, heart disease, arthritis and cataracts. Antioxidants help protect us from these conditions by repairing cellular damage caused by free radicals and by binding to free radicals to protect cells.

With the help of a grant from Golden LEAF, Boyd is exploring ways to use several North Carolina-grown fruits, including muscadines and blackberries, to blend their juices with blueberries. His work builds on wine-making research by Dr. Dan Carroll, semi-retired professor of food science.

The state’s blueberry crop comes in rapidly during the summer, and much of it is quick-frozen for use in products throughout the year. Juices and other products would provide a market for extending the use of blueberries year round.

Blueberries, particularly the skins, are high in blue-red pigment anthocyanidins, which possess antioxidant properties. But traditional pasteurizing of fruit juices at high temperatures can cause juices to lose flavor.

Boyd is exploring how the use of hydrostatic pressure or nanofiltration could help rid juices of microorganisms without depleting flavor. And by retaining anthocyanidins, these processes can also increase the antioxidant value of the juice.

Blueberries are not often used in juices because they are more expensive than other fruits, but Boyd is hoping to change that thinking. He and his graduate students are looking at chemical changes that occur in blueberry juice or wine over time and whether the juice retains its flavor when stored at room temperature.

Carroll says he has experimented with fruit juice blends that include blueberries, muscadines and apples. Wine made with blueberries may actually have additional antioxidants because fermentation helps release antioxidants.

And the researchers are looking at the antioxidant properties of different blueberry varieties to determine which may provide the strongest protection against free radicals. Low-bush varieties typically have higher antioxidant properties than high-bush varieties, Boyd said.

Boyd is also exploring other uses for blueberries, including jams and jellies. When used in juices, blueberries, like other fruits, leave behind skins that are loaded with antioxidants. He tried adding a blend of blueberry and muscadine skins to sausage to create a healthier product. (His group is also working on extracting and stabilizing the pigments or anthocyanidins from blueberry skins for use as coloring agents and natural antioxidants.)

Adding the fruit reduces the fat content and extends the shelf life of the sausage, Boyd said. While the department’s taste panel liked the flavor of the sausage with added fruit, members were turned off by the resulting blue color of the sausage, he said.

So while blueberry sausage may stay on the drawing board, Boyd and his colleagues are closer to helping blueberry growers find new ways to incorporate their product into other foods, thereby creating new markets for North Carolina blueberries.