Comparative study of antioxidants in fresh and frozen blueberries and cranberries fruits

Abstract

The beneficial effect of blueberries and cranberries consumption is largely due to the high content of biomolecules with antioxidant properties, the most important are vitamins (especially vitamin C and provitamins A - carotenoids), anthocyanins and phenolic compounds. The purpose of this work is to determine how the blueberry and cranberry preservation at -80ºC influence the antioxidant content of these fruits. The biochemical parameters analyzed were as follows: anthocyanin pigments (total anthocyanin extraction and dosing, anthocyanin profile by TLC and HPLC chromatography); carotenoid pigments (total carotenoid extraction and dosing, carotenoid profile by HPLC); determination of ascorbic acid and total phenolic compounds. Antioxidants profile is different in blueberry and cranberry, both of quality and quantitative point of view. Preserving berries by freezing them for a period of time between 1 and 3 months induce different changes in the content of specific antioxidants: the concentration of vitamin C and anthocyanin pigments decreases, simultaneously with an increase in concentration of polyphenols and carotenoids.