Onions (Allium cepa L.) are important source of bioactive compounds including polyphenols and have potential beneficial properties for human health. Selenium (Se) is an essential micronutrient that is required in small amounts. The aim of the research was to find out how selenium (Se) treatment affects on the quality of onion (Allium cepa L.). The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl).The Se treatment increased the content of total polyphenols (TCA) and antioxidant activity (AA). The content of total polyphenols in samples of onion during vegatation period moved in the range from 508.16±27.59 to 607.56±23.15. In this work was watched also the influence of potassium on antioxidant activity, where values were in interval from 25.90±0.47 to 39.72±2.64.
Selenium, onion, total polyphenols, antioxidant activity