THE RESEARCH OF TOTAL POLYPHENOLS CONTENT AND THEIR CHANGES IN DIFFERENT VARIETIES OF POTATOES

Polyphenols are secondary metabolites of plants with antioxidant properties. In this work we research the changes in the content of total polyphenols in five varieties of potatoes (Rumelia, Arwen, Megan, Malvína, Erídia). Potatoes were grown at the stage of full maturity from Matejovce nad Hornádom, region of Poprad. Total polyphenols we determined in whole peeled potatoes; in the outside part of peeled potato tubers (1 cm); in inside part of potato tubers (mean 2 cm) and in the whole peel-boiled potatoes. The total polyphenols content was determined by spectrophotometry (λ = 765 nm) and it was used lyophilized samples in ethanol extracts. In whole peeled potatoes was the content of total polyphenols in the range from 243.34 mg.kg-1 DM (cv. Rumelia) to 446.38 mg.kg-1 DM (cv. Megan), in the outside part of peeled potato tubers was content in the range from 190.45 mg.kg-1 (cv. Rumelia) to 446.84 mg.kg-1 DM (cv. Malvína) and in inside part of potato tubers from 245.51 mg.kg-1 to 446.26 mg.kg-1 DM (Arwen < Rumelia < Megan < Erídia < Malvína). In the whole peel-boiled potatoes was the lowest content of total polyphenols in variety Rumelia (252.5 mg.kg-1 DM) and the highest content in variety Megan (440.54 mg.kg-1 DM). Results were statistically evaluated by the Analysis of Variance (ANOVA – Multiple Range Tests, Method: 95.0 percent LSD) using statistical software STATGRAPHICS (Centurion XVI.I, USA) and the regression and correlation analysis (Microsoft Excel) was used.