THE IMPACT OF PLANT MATERIAL FREEZING AND EXTRACTANT ACIDIFYING ON THE ANTIOXIDANT POTENTIAL AND PIGMENTS CONTENT IN EXTRACTS AND RAW MATERIALS OF DIFFERENT CARROT VARIETIES

Abstract

The antioxidant activities of extracts of purple, yellow and orange carrot varieties were evaluated by in vitro methods i.e. DPPH, ABTS, FRAP, and CUPRAC. The total polyphenols concentration was evaluated using Folin-Ciocalteu technique. The content of anthocyanins, chlorophylls and carotenoids was evaluated in fresh and frozen carrots. The anthocyanin concentration was also determined in carrot extracts. The effect of certain parameters of ultrasound-assisted extraction, i.e. extraction time, concentration and acidifying of extractant, as well as the type of raw material (fresh or frozen) was analyzed. The antioxidant potential as well as content of polyphenols and plant pigments were the highest in purple carrot extracts. The most effective extractant seems to be 70% (v/v) ethanol. The extension of the extraction time, in majority of cases, led to an increase of antioxidant activity of extracts, whereas the freezing of raw material generally decreased the above-mentioned activities. The effect of acidification of extractant is ambiguous and depends on the method applied to evaluate antioxidant activity.

Keywords

• Daucus carota L.
• antioxidant activity
• ultrasound-assisted extraction
• plant pigments
• freezing
• solvent acidifying