Physicochemical and morphological characterisation of açai (Euterpe oleraceae Mart.) powder produced with different carrier agents

Physicochemical and morphological properties of açai powder produced with different carrier agents were evaluated in this work. Powders were produced by spray drying, using maltodextrin 10DE, maltodextrin 20DE, gum arabic and tapioca starch as carrier agents. Powder characterisation included analysis of moisture content, water activity, solubility, hygroscopicity, particle size distribution, morphology, total polyphenolics and antioxidant activity. Results showed that the samples produced with maltodextrin 20DE and gum arabic presented the smallest size and highest hygroscopicity. The powder produced with tapioca starch exhibited the lowest hygroscopity and solubility, and the highest mean diameter. With regard to morphology, all particles exhibited spherical and shrivelled surfaces, except those produced with tapioca starch, which exhibited rounded and smooth surfaces. Powders produced with maltodextrins and gum arabic showed high polyphenolic retention and antioxidant activity preservation after storage at 40 °C for 15 days, while for the particles produced with tapioca starch, this protective effect was less pronounced.