An optimized technique for the production of composite materials based on sodium alginate and nanofillers was developed. Inorganic boehmite and hydroxyapatite nanoparticles were utilized as fillers. To change the properties of the polymer beads, the fillers were obtained under various conditions including the order of reagents adding, pH and temperature of the reaction medium, and type of heating ensuring hydrothermal synthesis conditions. Samples of different sizes and shapes were characterized using X-ray diffraction method, Fourier-transform infrared spectroscopy, transmission electron microscopy analysis and specific surface area measurement conducted using Brunauer–Emmett–Teller method. The beads were examined for swelling properties and polyphenol release. The best bead swelling performance is observed for plate-like boehmite nanofiller and larger hydroxyapatite nanorods with the values of 120 % and 73 %, respectively. The antioxidant release depends on the nature and size of filler. For beads filled with large boehmite plate-like nanoparticles the maximum polyphenol release of 68 % is shown. At the same time, beads filled with smaller hydroxyapatite nanorods demonstrate better polyphenol release function among other hydroxyapatite fillers. The additional cross-linking occurring during the formation of hydroxyapatite-filled beads and caused by the presence of calcium atoms on the filler surface was taken into account. The dependence of beads characteristics on filler's nature, shape and size is revealed.