Anthocyanin stability and antioxidant activity of powdered açai juice was evaluated throughout
120 days. Powders were produced by spray drying using four types of carrier agents: maltodextrin
10DE, maltodextrin 20DE, gum Arabic and tapioca starch. Samples were stored at different temperatures
(25 and 35 C) and water activities (0.328 and 0.529), in order to verify the effect of these conditions on
anthocyanin degradation and antioxidant activity reduction. Anthocyanin degradation exhibited two
first-order kinetics: the first one, with higher reaction rate constant, up to 45–60 days of storage, and
the second one, after this period, with lower degradation rate. Both temperature and water activity negatively
affected anthocyanin stability. Antioxidant activity also decreased with increasing water activity,
but was higher for the powders stored at 35 C. Maltodextrin 10DE was the carrier agent that showed the
best pigment protection and the highest antioxidant activity, for all the conditions studied.