Oleofoam design based on coexistence of lipophilic and hydrophilic structuring agents: glycerol monostearate and phycocyanin/fucoidan/xanthan gum.

In the present study, oleogel and resultant oleofoam were produced based on a combination of direct and indirect oleogelation methods (referred to as combined-oleogel and combined-oleofoam). They were structured by glycerol monostearate (GMS) and phycocyanin/fucoidan/xanthan gum (PC/FU/XG). Furthermore, they were compared to control samples (i.e., oleogel and resultant oleofoam structured only by GMS, referred to as control-oleogel and control-oleofoam) in terms of various properties. The presence of networks within the combined-oleogel as well as almost uniformly distributed air bubbles in combined-oleofoam were perceived via microstructure inspection, while control-oleofoam had more elongated air bubbles with larger sizes. This can indicate the effect of PC and/or PC/FU complex on stabilizing the air bubbles and the effect of additional network (PC/FU/XG), in addition to the GMS crystalline network. Besides, solid-like behavior for oleogels and oleofoams was confirmed. In addition, a significantly higher degree of structure recovery for combined-oleofoam than for combined-oleogel was found during thixotropic behavior testing. In addition, combined-oleofoam had a significantly higher degree of structure recovery than control-oleofoam, representing a higher ability of combined-oleofoam to recover the structure after deformation. Moreover, β' and β crystals were detected in oleogels and oleofoams. According to the FTIR spectra, hydrogen bonding in the network was identified. Furthermore, slight differences in melting temperatures between the combined-oleogel and combined-oleofoam were found. Overall, this study suggests that oleofoam can be constructed by simultaneously using hydrophilic biopolymers and GMS crystals.