Exploitation of κ-carrageenan aerogels as template for edible oleogel preparation

In the current research, oleogels were prepared by using kappa-carrageenan aerogels as template. In particular, hydrogels containing increasing concentration (0.4, 1.0, and 2.0% w/w) of kappa-carrageenan were firstly converted into alcoholgel and subsequently dried by using supercritical CO2 to obtain aerogels. The latter were porous and structurally stable materials with high mechanical strength. The polymer content affected the aerogel structure: increasing the initial kappa-carrageenan concentration a coarser structure with larger polymer aggregates was obtained. However, the aerogel obtained at intermediate polymer concentration resulted the firmest one, probably due to the formation of a less aerated and more isotropic structure. Aerogels demonstrated a reduced capacity of water vapor sorption, remaining glassy and porous at room temperature at relative humidity lower than 60%. Aerogels showed a good capacity of oil absorption. The maximum oil loading capacity (about 80%) was obtained for aerogel containing the highest kappa-carrageenan content. Thus, it can be concluded that aerogels based on the structuring of water soluble polymers have potential as material for oil absorption and delivery. (C) 2017 Elsevier Ltd. All rights reserved.