Development of gelatin/camellia oil oleogels as fat substitutes via a novel strategy: Covalent crosslinking of electrospun nanofiber

An innovative and facile method was developed to fabricate oleogels from biopolymers. Gelatin nanofibers were prepared by electrospinning and crosslinked by genipin, and through the one-step homogenization of nanofiber membranes and camellia oil, electrospun fiber-based oleogels (EFO) were obtained. Genipin crosslinking enhanced the fiber diameter from 138.66 to 311.92 nm, providing different nanofiber modules for oleogel preparation. The network structure in EFO was confirmed by microstructure examination, and fiber content and crosslinking influenced the protein conformation and thermal stabilities. Adding nanofiber in EFO effectively increased the apparent viscosity and oil binding capacity (up to 79.32%) while crosslinking decreased the values to some extent. Nevertheless, the highly crosslinked samples with a high fiber content had the best thixotropic recovery (83.24%). Crosslinking also contributed to a steadier free fatty acid release performances with a final release amount of 50.31%. Furthermore, EFO was successfully utilized to replace commercial solid fats in making cookies with considerable performances. Results indicated that EFO could be conveniently prepared by the new method, and samples were promising as fat substitutes in healthy diets. In addition, due to the simplicity and universality of this method, more biopolymers and modification strategies could be accessible in electrospun nanofiber dispersing oleogel systems.