By Lynn A. Kuntz, Editor in Chief
After scouring the far corners of the Earth for exotic superfruits, it seems all this time we’ve had one of the best right in our own backyard—the blueberry.
Blueberries are native to North America. Native Americans were using them long before Europeans arrived, not only as food, but as medicine. For example, they used blueberry-leaf tea as a blood tonic, and blueberry juice as a cough medicine. They ate fresh berries, and added blueberries to stews, soups and meats.
The interest in blueberries keeps on rolling to this day; they’re found in everything from pastries to yogurt to premium pet food. According to Mintel, Chicago, more than 1,200 new products containing blueberries were introduced in 2010.
“Blueberries have always been popular because of their natural deliciousness, but their popularity soared with the advent of antioxidant-awareness," says Tom Payne, industry specialist, U. S. Highbush Blueberry Council, Folsom, CA. “Blueberries are especially successful because they are both an easy snack, eaten fresh, and an easy-to-formulate ingredient for product development in all categories, from dairy and baked goods to beverages, cereals and snacks."
Beating around the blueberry bush
Blueberries are members of the genus Vaccinium, the same family of plants as cranberries. Among the many types, three predominate: highbush (“cultivated" northern and southern varieties), lowbush (“wild") and rabbiteye (native to the South). Cultivated, or highbush, berries make up approximately 2/3 of the blueberries grown in North America. Their large berries are more than 1/2 inch (12 mm) in diameter, but this varies from smaller (1.0 to 1.5 gram) fruits to large (greater than 2.5 grams), depending on growing conditions and cultivar.
Lowbush blueberries are smaller than highbush varieties (3/8 inch, or 10 mm), so “wild blueberries deliver more than twice the number of berries per pound than the larger cultivated blueberries, about 1,300 to 1,500 berries per pound, “ says Mike Collins, vice president, Food & Wellness Group, Portland, ME, and spokesperson for the Wild Blueberry Association of North America, Old Town, ME.
While some have similar characteristics to highbush varieties, in general, rabbiteye blueberries tend to have darker fruit, more noticeable seeds, thicker skins and have a somewhat gritty texture (similar to pears). One study found rabbiteye fruit to have a higher pulp pH, percent soluble solids, sugar:acid ratio and firmness compared to highbush berries.
Wild blueberries also have a “sweet and tangy" flavor compared to the typically more mellow cultivated berries, according to Collins. The technical explanation lies in the different composition. The sugars in lowbush blueberries include glucose and fructose, while highbush blueberries contain fructose, glucose and low levels of sucrose, and the profile of major acids also differs between lowbush blueberries and highbush and rabbiteye blueberries. Lowbush blueberries’ aroma is produced predominately by esters and alcohols. Highbush volatiles are aromatic hydrocarbons, esters, terpenes and long-chain alcohols. In all types, flavor and composition is affected by cultivar, fruit maturity and storage conditions.
Blueberries’ claim to superfruit status is owed in large measure to their antioxidant content. Research shows that dietary antioxidants may have a role in reducing oxidative stress, and therefore might slow aging and reduce the risk of many chronic and degenerative diseases, such as cancer, heart disease and Alzheimer's. Oxygen Radical Absorbance Capacity (ORAC) of a food measures its total antioxidant activity.
Depending on the research used, the original fruit using the superfruit title, pomegranate, has an ORAC of about 4,500. (Açaí seems to have an ORAC higher than 10,000, but it’s not a fruit eaten out of hand.) According to the "USDA Database for Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods (Release 2)," that compares to cultivated blueberries' ORAC of 4,669 (total phenolics 311) and wild blueberries' ORAC of 9,621 (total phenolics 429). For additional antioxidant content, Collins also cites the "USDA Database for the Flavonoid Content of Selected Foods (Release 2.1)," saying, “this measurement indicates wild blueberries have nearly two times the anthocyanidin content of cultivated blueberries." Anthocyanin compounds also give the fruit its characteristic blue color. The flavonoids quercetin, ellagic acid and chlorogenic acid add to the antioxidant power.
In 100 grams of blueberries you’ll find 57 calories, 2.4 grams of fiber and 9.7 grams vitamin C. They also contain minerals such as calcium, selenium and zinc, resveratrol, and the aforementioned antioxidants. While no one has been able to exactly pinpoint what an ORAC score means in terms of specific benefits, research is teasing out the health benefits of blueberry consumption. Studies have been performed on blueberries’ effects on cancers, inflammation, heart health, digestive health and more.