Scientists at the agency's Agricultural Research Service (ARS) have developed the new variety of the healthy berry through cross-breeding an Alaskan species with the typical American cranberry. The new berry contains multiple times the absorbable antioxidants found in the American variety, according to the ARS researchers. Following their examination of other cranberry species, they identified the Vaccinium oxycoccus variety from Alaska to be genetically similar enough to the American cranberry to allow for interspecies hybridization. The Alaskan berry was particularly attractive because of the make up of its anthocyanins, explained the researchers. Anthocyanins, a form of flavonoids, are the source of the blue, purple and red colour of berries, grapes and some other fruits and vegetables. These pigments also function as antioxidants, believed to protect the human body from oxidative damage that may lead to heart disease, cancer and ageing. Hundreds of different anthocyanins exist in nature, all with slightly different chemical compositions. According to ARS, the anthocyanins in the Alaskan cranberry are mostly linked to glucose. This gives them a higher antioxidant capacity than the anthocyanins found in other berries, which are mostly bound to sugars. In addition, flavonoids bound to glucose are said to be more readily absorbed in the human gut. ARS said the first generation of its experimental cranberry variety contains around 50 percent anthocyanin linked to glucose, compared to less than five percent in the American variety. "The progeny of these crosses deliver two benefits: the proanthocyanidins long known for inhibiting bacterial E coli from sticking to the lining of the urinary tract, and higher amounts of the potentially well-absorbed antioxidative anthocyanins," said plant pathologist James Polashock. "The next step is to move the traits for glucose-linked anthocyanins from the experimental cranberry line into a horticulturally acceptable variety that can be used by growers for market." The popularity of cranberries has been increasing in recent years as a combination of strong marketing campaigns and a body of scientific evidence revealing the fruit's health benefits has contributed to growing consumer awareness and interest in the product. The berries can be found in more than 2,000 products and have been gaining a wealth of support for their healthy benefits. These include preventing the build up of bacteria that causes urinary tract infection. According to 2006 estimates, the US and Canada produce about 7 to 7.6 million 100-pound barrels of cranberries every year. The vertically integrated cranberry firm Ocean Spray claims to produce around two thirds of the cranberries on the US market. Ocean Spray last summer announced it would expand its processing capacity in an effort to catch up with soaring global demand for products containing sweetened dried cranberries. The average retail price of a 12-ounce package of fresh cranberries rose eight cents last year to $2.20 from $2.12 in 2006, according to the American Farm Bureau Federation.