Functional starch and alginate-pectin aerogels generated from 3D-printed biopolymers using supercritical carbon dioxide drying

The development of structured polysaccharide aerogels with controllable architecture and functionality remains a key challenge. This study addressed this gap by integrating starch-, alginate-, and pectin-based aerogel formulations using 3D food printing (3DFOODP) combined with supercritical carbon dioxide (SC-CO 2 ) drying. This integrated approach, for the first time, enables precise control over both macro- and microstructure, representing a novel 3DFOODP strategy for designing polysaccharide aerogels beyond conventional fabrication methods. The prepared aerogels exhibited open porous structures, high specific surface areas (50–92 m 2 /g for starch-based, 252–343 m 2 /g for alginate- and pectin-based, and 81–115 m 2 /g for starch–alginate/pectin formulations), low bulk densities (<0.26 g/cm 3 ), and high porosities (>82%). The integration of 3DFOODP and SC-CO 2 drying produced highly homogeneous and interconnected porous structures, while a partial loss of crystallinity was observed after aerogel formation. Swelling tests in phosphate-buffered saline (PBS, pH 6.8) showed that alginate- and pectin-based aerogels exhibited significant swelling ratios exceeding 300%. In contrast, limited swelling under acidic conditions (HCl, pH 1.2) indicated protonation of functional groups and distinct pH-responsive behavior. These findings provide new insights into the use of 3DFOODP to create complex structures in the generation of aerogels for their potential use in controlled delivery systems.