US EPA

6399079 

Journal Article 

Modification of the health-promoting value of potato tubers field grown under drought stress: emphasis on dietary antioxidant and glycoalkaloid contents in five native andean cultivars (Solanum tuberosum L.) 

Andre, CM; Schafleitner, R; Guignard, C; Oufir, M; Aliaga, CA; Nomberto, G; Hoffmann, L; Hausman, JF; Evers, D; Larondelle, Y 

2009 

Yes 

Journal of Agricultural and Food Chemistry
ISSN: 0021-8561
EISSN: 1520-5118 

57 

2 

599-609 

English 

19105644 

10.1021/jf8025452 

WOS:000262665000041 

The effects of drought stress on dietary antioxidant and glycoalkaloid contents in potato tubers were investigated using a selection of five native Andean cultivars. Both freshly harvested and 4 month-stored tubers were analyzed. Responses to drought stress were highly cultivar-specific. The antioxidant contents of the yellow tuber-bearing cultivars (Sipancachi and SS-2613) were weakly affected by the drought treatment, whereas the pigmented cultivars demonstrated highly cultivar-dependent variations. A drastic reduction of anthocyanins and other polyphenols was revealed in the red- (Sullu) and purple-fleshed (Guincho Negra) cultivars, whereas an increase was shown in the purple-skinned and yellow-fleshed cultivar (Huata Colorada). The hydrophilic antioxidant capacity (evaluated by Folin-Ciocalteu and H-oxygen radical absorbance capacity assays) was highly correlated with the polyphenol content and followed, therefore, the same behavior upon drought. Carotenoid contents, including beta-carotene, as well as vitamin E, tended to increase or remain stable following drought exposure, except for the cultivar Sullu, in which the level of these lipophilic antioxidants was decreased. Vitamin C contents were not affected by drought with the exception of Guincho Negra, in which the level was increased. These variations of health-promoting compounds were associated with increased or stable levels of the toxic glycoalkaloids, alpha-solanine and alpha-chaconine. Storage at 10 degrees C for 4 months tended to decrease the concentrations of all dietary antioxidants, except those of vitamin E. This storage also reduced the drought-induced variations observed in freshly harvested tubers. These results were discussed in terms of their implications for human diet and health as well as in plant stress defense mechanisms. 

; Alkaloids/analysis; Antioxidants/analysis; Ascorbic Acid/analysis; Carotenoids/analysis; Droughts; Flavonoids/analysis; Nutritive Value; Phenols/analysis; Plant Tubers/chemistry; Plant Tubers/growth & development; Polyphenols; Solanum tuberosum/chemistry; Solanum tuberosum/growth & development; Index Medicus/