Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 10/20/2007
Publication Date: 4/10/2008
Citation: Simon, P.W., Tanumihardjo, S.A., Clevidence, B.A., Novotny Dura, J. 2008. Role of Color and Pigments in Breeding, Genetics, and Nutritional Improvement of Carrots. In: Culver, C.A., Wrolstad, R.E., editors. Color Quality of Fresh and Processed Foods. Washington, D.C.: Oxford University Press. p. 151-165. Interpretive Summary: Carrot is known around the world today as a vegetable rich in the orange carotenoid pigments that form vitamin A. Carrots with different colors including yellow, red, and purple carrots are also known. We developed DNA markers to track genetic variation and set the stage for more efficient progress in breeding for altered carrot pigment content. These pigments in carrots are antioxidants and they serve an important role in promoting health since they have been associated with reduced risk of atherosclerosis, cancer, and in reduction of inflammation. Vegetables are often dismissed as a source of nutrients because nutrients in vegetables have been thought to have limited bioavailability, that is to say the nutrients are not well absorbed during digestion. We evaluated bioavailability with carrots of different colors bred by the USDA and found that the nutrients in carrots were generally bioavailable. We also evaluated consumer acceptance and demonstrated all the carrots were well-accepted by the consumer panel and therefore growers should be encouraged to cultivate specialty carrots to provide dietary sources of vitamin A and phytochemicals. Outreach activities with community gardens resulted in positive attitudes toward all the carrot colors. Seed companies and growers ranging from small-scale to large are beginning to direct their attention and resources to this wide array of carrot colors as this small niche market begins to grow. This research is of interest to nutritionists, geneticists, plant breeders, crop producers and consumers.
Technical Abstract: The color of carrots was an important attribute during its domestication as a root crop. Modern carrot researchers continue to study color, and carrot genetic stocks have been developed with not only orange, but also distinctive dark orange, red, yellow and purple color. Genes for 22 carotenoid biosynthetic enzymes have been mapped and cloned, and the alpha and beta-carotene in typical orange and dark orange carrots, lycopene in red carrots, lutein in yellow carrots, and anthocyanins in purple carrots have been demonstrated to be bioavailable. The function of carrot color genes largely remains unknown and the sources of wide variation in pigment absorption are unexplained, but carrot has been demonstrated to be a sustainable source of dietary provitamin A and other phytonutrients of interest for researchers and consumers.