Impregnation of passion fruit bagasse extract in alginate aerogel microparticles

Passion fruit bagasse extract (PFBE) is a rich source of polyphenols, including piceatannol. This work produced alginate (1, 2, 3 wt%) aerogel and investigated the impregnation of gallic acid (GA) and PFBE in alginate aerogel microparticles. The microparticles of ca. 100 μm in diameter were obtained by emulsion-gelation method, submitted to solvent exchange, wet impregnation (WI) and supercritical drying. Alginate aerogels derived from 1 wt% solution led to a higher GA loading and, therefore, this formulation was used to impregnate PFBE. The loading of PFBE, total phenolic, and piceatannol contents based on grams of raw aerogel were 0.62 g, 10.77 mg, and 741.85 μg, respectively, which means a loading efficiency of total phenolics and piceatannol of 47.1% and 34.7%. DSC analysis and X-ray diffraction showed that particles behave as amorphous materials and ORAC assay revealed that impregnated aerogel microparticles presented antioxidant capacity. Alginate aerogel microparticles presented as an appropriated material for drug loading, whereas WI and supercritical drying demonstrated to be useful techniques to load PBBE in aerogels.