|Brown, Charles - Chuck|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 4/15/2006
Publication Date: 5/1/2008
Citation: Brown, C.R., Culley, D., Wrolstad, R., Durst, R. 2008. Achieving Phytonutrient Enhancement in Potato by Breeding for Increased Pigment. Color Quality of Fresh and Processed Foods. Eds. C. Culver and R. Wrolstad. Oxford University Press, 2008. 102-113. Interpretive Summary: Colors in foods have a big impact on their appeal to the consumer. Natural pigments in fruits and vegetables are usually also bioactive compounds, which in many cases promote health. A high consumption of fruits and vegetables inevitably leads to ingestion of these phytopnutrients and a displacement of cholesterol-rich and lactose-laden foods, the consumption of which should be limited. Red and purple potatoes, especially those with colored flesh are rich in anthocyanins. Anthocyanins are strong antioxidants and anti-inflammatory agents. They have been linked to lower rates of heart disease, to lower incidence of certain types of cancer, and healthier eyes in the elderly. Potato flesh has compounds from another class of naturally occurring pigments, the carotenoids. The carotenoids in potato flesh are lutein and zeaxanthin which are major constituents of the human retina. Supplementation of the diet with large amounts of lutein has been shown to slow the progress of cataracts and age-related macular degeneration. The introduction of more colorful potatoes into the human diet can satisfy the urge to delve into interesting foods and also increase the consumption of health-promoting phytochemicals.
Technical Abstract: The re-discovery of color in potato has implications for the aesthetic and phytonuttient characteristics of potato as a food. Two methods of measurement of Oxygen Radical Absorbance Capacity (ORAC) adapted to hydrophilic and lipophilic compounds were applied. Total anthocyanin values varied between 9.5 and 38 mg per 100 g fresh weight (FW). The hydrophilic fraction ORAC measurements among anthocyanin rich clones varied between 250 and 1420 umoles Trolox equivalents per 100 g FW. These two variables were significantly correlated, r = 0.73, and with significant positive slope in linear regression. Measurement of total carotenoids revealed differing degrees of yellowness covered a range of total carotenoid extending from 35 to 795 micro g per 100 g FW. Dark yellow cultivars had roughly ten times more total carotenoid than white flesh cultivars. The lipophilic fraction ORAC values ranged from 4.6 to 15.3 nmoles alpha-tocopherol equivalents per 100 g FW. Total carotenoid was correlated with the lipophilic ORAC values, r = 0.77, and also had a statistically significant positive regression coefficient. Clones with red and yellow pigments visible in the flesh had anthocyanins and carotenoids in elevated levels and ORAC contributions from both fractions. The introgression of high levels of carotenoid from germplasm directly extracted from the Papa Amarilla (Yellow Potato) category of cultivars of South America into long-day adapted North American materials is presented here.