The ancient purple carrot is returning to its roots, this time to dye processed foods rather than the robes of Afghan royals. Researchers in California are preparing for increased demand for fruits and vegetables that pull double duty as dyes as the deadline approaches for when the European Union will require warning labels on synthetically colored foods. "There's a mad dash in Europe to get synthetic dyes out and put natural ones in, and it's coming across the Atlantic," said Stephen Lauro, general manager of ColorMaker in Anaheim, which turns beets, berries, cabbages and carrots into dyes for products such as Gerber toddler foods and Tang breakfast drink. "It was dumb luck and we stepped into it." Petroleum-based synthetic dyes approved by the US Food and Drug Administration commonly have been used in processed foods to help them mimic the product they are supposed to represent - for example, the red in some fast-food strawberry sundaes. "We eat with our eyes, and the first thing you evaluate is color," Lauro said. Among the best sources of natural vegetable dye are purple carrots, organically grown for the domestic gourmet market in the San Joaquin Valley by Grimmway Farms, which is supplying juice for experiments at California State Polytechnic University, Pomona. The carrots have been around thousands of years longer than their orange counterparts and are especially high in the antioxidant anthocyanin, a free-radical-fighting plant pigment that also colors blueberries and red wine grapes. "Mom always said vegetables are good for you but didn't know why," said Paul Verderber, juice division manager of Grimmway. "The colors are causing the goodness." The interest in natural sources of food colorings comes as researchers at Southampton University in England have linked some synthetic dyes with hyperactivity in children. The United Kingdom moved last year to ban some synthetic food dyes, and on January 1 the European Union will require that foods made with them carry the warning "may have an adverse effect on activity and attention in children." It means there are two international standards for food additives. Companies that sell in both countries often use petroleum-based dyes in the US, such as Red 40 and Yellow 6, but beet root, carrots and paprika in the UK. The Center for Science in the Public Interest, a consumer advocacy group, last year petitioned the FDA for warning labels and an eventual ban. The FDA has not yet responded, and spokeswoman Stephanie Kwisnek says the agency "will continue to closely monitor the scientific literature for new information regarding hyperactivity in children and consumptions of additives." Consumers are already making a change toward natural products, and companies such as ColorMaker are working to meet the demand from food manufacturers. The company currently gets its purple carrot dye from an obscure source in Turkey, but would prefer an organic domestic supply if researchers can figure out how to extract the same richness of color from varieties suitable to California's climate. The company has joined Ann Marie D. Craig, PhD., an assistant professor of food chemistry at Cal Poly, to extract more concentrated anthocyanins to prepare the state's puny-but-potent purple carrot crop for its potential new duty. "For something to come to the consumer market, it takes a significant amount of time and research," Craig said. "We are trying to get ahead on this." Purple carrots are especially attractive because they provide as much anthocyanin as the better known sources and are cheaper and easier to grow than blueberries. Craig, who devotes her career to studying natural colorants, is looking for ways to stabilize anthocyanin-based vegetable dyes, which tend to turn brown when heated, red in acidic foods and blue in alkaline. Her research is sponsored by Cal State's Agricultural Research Initiative, which funds projects to create new markets for homegrown products. "At the end of the day, California has the opportunity to become a major supplier," Lauro said. "With a small regulatory change, a brand-new market will develop and that will benefit carrots in the Central Valley."