Orange and Purple: A Better Combination Than You May Think
Scientists at the International Potato Center (CIP) are confident they can combine the well-known nutritional benefits of orange-fleshed sweetpotatoes with cancer-preventing properties in purple sweetpotato varieties.
The researchers were inspired to pursue this goal by the extraordinary success of orange-fleshed sweetpotatoes possessing high levels of beta-carotene (a precursor of vitamin A), in sub-Saharan Africa, where vitamin A deficiency condemns millions of children to blindness.
The pigmentation of purple-fleshed sweetpotato varieties is due to the presence of anthocyanins. Studies carried out at Kansas State University in the USA have revealed that two of these powerful antioxidants are able to inhibit the growth of cancer cells in the human colon.
“My nutritionist colleagues tell me that the anthocyanins in sweetpotato have good bioavailabilty, meaning they are easily absorbed from the digestive tract into the bloodstream, where they may have beneficial effects,” says Ted Carey, a CIP sweetpotato breeder based in Ghana.
At the Center’s experimental station in San Ramon, Peru, researchers have begun to build on such benefits by selecting different samples of orange, purple and white-fleshed sweetpotatoes from the CIP genebank and creating from these new crop populations with better agronomic and nutritional characteristics.
“We already have advanced and elite clones with high mineral and beta-carotene content,” says CIP researcher Federico Diaz, “and we are also looking at purple sweetpotato progenies with high anthocyanin content. Some clones contain both anthocyanin and beta-carotene. We are confident that these will have a major impact in the future. We calculate that in 3 years these materials will be ready to send to other continents for assessment in different agro-ecologies.”