Antioxidative activity of microcapsules with beetroot juice using gum Arabic as wall material

The antioxidative activity of encapsulated natural beet root juice was evaluated during storage at different water activities. In microcapsules of beetroot obtained by spray drying and stored at water activities of 0.110, 0.326 and 0.521 there were no significant differences in betalain concentration, color, antioxidant activity and redox potential during 45 days. However, the samples stored at a ws of 0.748 and 0.898 showed significant differences compared to those stored at 0.110, 0.326 and 0.521, but no difference was shown among the constituents of each group. In the samples stored at 0.748 and 0.898 the antioxidant activity increases, whereas the betalain concentration decreases due to the compounds that are formed while degradation of the betalains occurs. Water adsorption influences the stability of the product during storage.