Antioxidant activity of microcapsules of Rubus sp. juice using spray drying

Many studies have demonstrated the antioxidant activity and health benefits of the anthocyanins. The juice of Rubus sp. contains large amounts of anthocyanins and these flavonoids pigments give their characteristic color which tends to degrade easily, also its stability is affected during processing and storage, therefore spray drying can be used to avoid the degradation. The objective of the present work was to develop a powder by spray drying based on Rubus sp. juice and evaluate the physicochemical and antioxidant properties. Rubus sp was washed subsequently the juice was extracted and filtered. A gum arabic-juice solution was prepared in a 1:3 ratio (juice-solids) in order to be spray dried. Anthocyanins concentration, antioxidant activity, color, optical density and redox potential was measured to juice and the capsules obtained. The juice presents a high concentration of anthocyanins, redox potential and polyphenol. Samples of capsules were storage at 0.11, 0.33 and 0.52 of water activity and no significant differences in anthocyanins concentration, color, antioxidant activity and redox potential during 45 days of storage. The stability of the anthocyanins contained in the powder product and the antioxidant activity of the microcapsules depends on the water activity at which they are stored. Therefore, the microcapsules described in this study represent an interesting food additive for incorporation into functional foods, both as an antioxidant and as a colorant.