Development of nanoparticles with anthocyanins from açaí by electrospraying process

Electrospraying uses electric potential differences for nanoparticles formation, thus, the objective of the study was to evaluate the production of nanoparticles with açai anthocyanins using the electrospraying method. The process parameters found were feeding rate of 250 µL h−1, distance between capillary and collector of 15 cm, capillary diameter of 0.45 mm and electrical potential of 20 kV, at controlled temperature of 20 ± 2 °C and relative humidity of 50 ± 2%. To the maltodextrin nanoparticles were added 3% (v/v) of açaí anthocyanin extract (previously tested maximum concentration that produced nanoparticles). The nanoparticles were characterized by thermogravimetric analysis (TGA), Fourier transform spectroscopy (FTIR), nanoencapsulation efficiency (%EE), transmission electron microscopy (TEM) and antioxidant analysis (ABTS and DPPH). Then, the nanoparticles were characterized, which showed diameters around 117 ± 48 nm, nanoencapsulation efficiency 73% and the maltodextrin nanoparticles with anthocyanins showed 54% and 34% inhibition of the DPPH and ABTS radical, respectively. With TEM it was possible to visualize the compound of interest in the inner part of the nanosphere and the protection of the maltodextrin in the outer part. With the results found, it is possible to state that the electrospray technology is efficient for the production of maltodextrin nanoparticles with açaí anthocyanins, which can be used in powdered foods with the nutritional appeal of antioxidants.