VARIATION OF ANTHOCYANIN AND CAROTENOID CONTENTS AND ASSOCIATED ANTIOXIDANT VALUES IN POTATO BREEDING LINES

Authors: Brown, Charles; CULLEY, D - BATTELLE PNNL; Yang, Ching Pa; DURST, R - OREGON STATE UNIV; WROLSTAD, R - OREGON STATE UNIV

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/11/2004
Publication Date: 3/8/2005
Citation: Brown, C.R., Culley, D., Yang, C., Durst, R., Wrolstad, R. 2005. Variation of anthocyanin and carotenoid contents and associated antioxidant values in potato breeding lines. Journal of the American Society for Horticultural Science. 130(2):174-180.

Interpretive Summary: The role that potato plays in the human diet is dominated by the perception that it is a starchy vegetable. The research described in this article documents potatoes that have unusual characteristics. Taking advantage of natural genetic variation of the potato types with red or purple flesh high in a type of pigment called anthocyanin, were selected by crossing and selection. Anthocyanins, which are generally red or blue, are very common in foods, and available to function as antioxidants. Likewise, carotenoids are common in foods and generally are yellow, orange or red in color and also function as antioxidants. Antioxidants are compounds that retard the damage that oxidized compound can cause that lead to heart disease and certain cancers. A diet rich in antioxidant-laden foods is one of the guidelines for a healthy nutrition. Potatoes with levels of anthocyanins and carotenoids higher than normal also have a much higher than normal antioxidant status. Highly pigmented potatoes are generally called specialty potatoes at the present time. However, consumer groups, growers and companies that process or market fresh potatoes to grocery chains are unified in their interest to find high antioxidant potatoes that the growers can grow profitably and the consumer will accept as part of their diet. This research will result in new market niches and new attributes that will change the perception of the potato from being primarily a source of starch to a food also consumed for its antioxidant properties.

Technical Abstract: A breeding effort designed to increase the antioxidant level of potato by means of high concentrations of anthocyanins and/or carotenoids provided selected materials for analysis. Extraction methods suitable for hydrophilic and lipophilic compounds were applied. Estimates of total anthocyanin and total carotenoid were made. 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 FW. The hydrophilic fraction ORAC measurements among anthocyanin rich clones varied between 7.6 and 14.2 mg per 100 g FW Trolox equivalents. These two variables were significantly correlated and with significant positive slope in linear regression. Measurement of total carotenoids revealed differing degrees of yellowness covered a range of total carotenoid ranging from 40 to 800 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 2 to 7 micro g per 100 g FW tocopherol equivalents. Total carotenoid was correlated with the lipophilic ORAC values with 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 present in the Papa Amarilla (Yellow Potato) category of cultivars of South America into long-day adapted North American materials is presented here. Although anthocyanins and carotenoids are major contributors to antioxidant activity, other constituents of potato flesh likely play significant roles in total antioxidant values.