Interactions of cellulose cryogels and aerogels with water and oil: Structure-function relationships

Food-grade porous materials, aerogels and so-called cryogels, were prepared from cellulose hydrogels obtained solutions at increasing concentration (3, 4, 5%, w/w) by supercritical-CO2-drying (SCD) freeze-drying (FD), respectively. The structure depended on the applied drying technique, with showing a denser network pores <200 nm in diameter, specific surface area of 370–380 m2g-1, porosity 92–94%. Cryogels presented larger (2–5 ?m diameter), much lower (around 30 m2g-1), higher (95–96%). Water vapor adsorption cryogels was than that neat microcrystalline cellulose. absorption water oil investigated as function time equilibrium. While almost immediately absorbed both longer needed to reach Moreover, required cryogels. Material morphology governed kinetics absorption; equilibrium directly dependent material pore volume rather its or material-fluid affinity. As result, due their volume, amount (4–8 gfluid/gdry matter) (8–12 matter). All samples showed high fluid holding capacity (>96%). caused firmness decrease, but oil-filled materials same unloaded ones. This study demonstrates food-grade can be structurally designed varying techniques obtain controlled food loading.