Biocompounds and physical properties of açaí pulp dried by different methods

The aim of the study was to evaluate the biocompounds content and physical characteristics of açaí pulp dried by different methods in order to determine the most suitable drying method. The açaí pulp with a high content of lipids (53.31 g/100 g) was dried using spouted bed, freeze dryer and spray dryer. The samples were evaluated for anthocyanins, carotenoids and moisture content, and also for color and microstructure parameters. All samples showed moisture content less than 5 g/100 g. Powders obtained by freeze dryer and spouted bed showed lower color difference than fresh pulp. Microstructure analysis exhibited particles with irregular surfaces and diameters less than 100 μm. The açaí pulp dried by freeze drying presented the best results under the conditions and methods evaluated, once it resulted in a product with higher contents of anthocyanins (5.87 ± 0.53 mg/g of dry matter) and carotenoids (38.28 ± 0.69 μg/g of dry matter), as well as lower moisture content (2.65 ± 0.11 g/100 g). Furthermore, no lipid oxidation occurred in the freeze-drying pulp. Therefore, we concluded that açaí pulp can be dried and still preserve high concentration of biocompounds, and also physical properties, being suitable to be applied in healthy foods.