Açai (Euterpe precatoria Mart.) is a fruit with tremendous bioactive potential, but its high perishability necessitates the use of technologies to improve its stability and further enhance its bioactivity, such as microencapsulation by spray drying. Maltodextrin (MD) and gum Arabic (GA) are commonly used encapsulants in spray drying, but their combination for the microencapsulation of açai extract has not been studied. This study aimed to optimize the microencapsulation of açai extract using spray drying, evaluating its effect on the physicochemical and functional properties of the microparticles (MPs). Optimization was performed using response surface methodology with a central composite rotatable design, considering inlet air temperature (IAT) and polymer ratio (GA:MD) as factors. The optimal conditions were 135 °C IAT and a 50:50 GA:MD, under which a process yield of 76.05%, total phenolic compounds of 2791.83 mg GAE/100 g, and hygroscopicity (HYG) of 7.28% were obtained. Solubility (WSI) and total anthocyanin content (TAC) were not optimized due to lack of fit (p < 0.05). The experimental validation showed precise agreement between predicted and experimental values, with relative errors of less than 5%. The MPs presented spherical forms with rough surfaces. The effectiveness of the microencapsulation process demonstrates the potential of açai MPs as possible functional ingredients for future food applications.

Euterpe precatoria Mart. (açaí) is a superfruit with high nutritional and functional value; however, its high perishability accelerates the degradation of its bioactive compounds. Therefore, technologies such as microencapsulation allow for its preservation, improve its bioavailability, and extend its shelf life. The objective of this study was to optimize the microencapsulation process of açaí extract via spray drying, using response surface methodology (RSM) and a central composite design (CCD), in order to evaluate the effect of inlet air temperature (IAT) and the gum Arabic: maltodextrin (GA:MD) ratio on the total phenolic content (TPC) and total anthocyanin content (TAC), antioxidant capacity (ABTS, DPPH), as well as on the water-solubility index (WSI) and hygroscopicity (HYG) of the resulting powder. The desirability function (D) indicated that an IAT of 135 °C and a GA:MD ratio of 25:75 constitute the optimal conditions for spray-drying the açaí extract, under which the following values were obtained: 93.49% WSI, 7.42% HYG, 3291.22 mg GAE/100 g TPC, and 115.89 mg C3G/100 g TAC. Experimental validation yielded values within the 95% confidence interval established for the model’s predictions. Scanning electron microscopy analysis (SEM) revealed predominantly spherical açaí powders with smooth or slightly wrinkled surfaces, and microparticle diameters ranging from 2.10 to 24.22 μm. This indicates that, under the conditions evaluated, favorable results were obtained in terms of the physicochemical properties and the retention of TPC (up to 92.15%) and TAC (up to 84.60%) in the powder. Therefore, these results provide an experimental basis for the development of value-added products from Amazonian fruits.