Formation of nanoporous aerogels from wheat starch

• Biodegradable nanoporous aerogels were obtained from wheat starch using SC-CO2 drying.
• The highest surface area of the wheat starch aerogels was 59.7 m2/g.
• Average pore size of the wheat starch aerogels was 20 nm.
• Densities of the wheat starch aerogels ranged between 0.05–0.29 g/cm3.
• Wheat starch aerogels were stable up to 280 °C.

Biodegradable nanoporous aerogels were obtained from wheat starch using a simple and green method based on supercritical carbon dioxide (SC-CO2) drying. Effects of processing parameters (temperature, wheat starch concentration and mixing rate during gelatinization; temperature, pressure, and flow rate of CO2, during SC-CO2 drying) on the aerogel formation were investigated, and optimized for the highest surface area and smallest pore size of the aerogels. At the optimized conditions, wheat starch aerogels had surface areas between 52.6–59.7 m2/g and densities ranging between 0.05–0.29 g/cm3. The average pore size of the starch aerogels was 20 nm. Starch aerogels were stable up to 280 °C. Due to high surface area and nanoporous structure, wheat starch aerogels are promising carrier systems for bioactives and drugs in food and pharmaceutical industries.