Barley beta-glucan aerogels via supercritical CO2 drying

Low density, highly porous aerogels have a variety of applications. Through supercritical CO2 (SCCO2) drying, pore liquid can be removed with little to none of the damage associated with conventional drying techniques for wet gels. Gels formed using a barley β-glucan concentrate at 5, 6 and 7% (w/v) levels were dried using SCCO2. These aerogels were compared to those formed using freeze drying and air drying, as well as SCCO2 + ethanol, and analyzed in terms of density, shrinkage, color and structural properties. SCCO2 aerogels had lower densities than air-dried gels and a more consistent structure than freeze-dried gels. β-Glucan concentration had no significant effect on density or surface area, with values of 0.20 g/cm3 and 166 m2/g, respectively, obtained for 5% β-glucan gels. As β-glucan aerogels are biodegradable, biocompatible, renewable and edible, they have great potential for application as delivery vehicles for nutraceuticals or pharmaceuticals.

► Aerogels were prepared successfully with β-glucan via SCCO2 drying. ► Drying technique had a larger effect on aerogel properties than polymer concentration. ► Mesoporous β-glucan aerogels (5%) had 0.20 g/cm3 density and 166 m2/g surface area.