Properties of starch-based aerogels incorporated with agar or microcrystalline cellulose

In this work, starch-based aerogels incorporated with agar or microcrystalline cellulose (MCC) were obtained via thermal gelation in aqueous media, retrogradation, solvent exchange using ethanol, and supercritical drying with carbon dioxide (CO2). The influence of starch concentration (10 and 15 wt%), agar or MCC addition (0, 0.25, 0.5, and 1 wt%), and gelatinization temperature (90 or 110 °C) on textural, mechanical, and thermal properties of the aerogels were investigated. The water absorption capacity and stability in aqueous media of the aerogels were also investigated. Produced aerogels were highly stable in water for 7 days, depending on the synthesis conditions. Higher polymer concentration and gelatinization temperature increased the compressive strength and Young's modulus of the aerogels. The results show that agar and MCC can modulate the properties of starch-based aerogels, opening numerous opportunities for investigation. The obtained aerogels have potential to be used in several areas such as controlled released of active compounds, absorbents, and as source of resistant starch.