Structure and Properties of Organogels Developed by Diosgenin in Canola Oil

Abstract

In this study, naturally occurring ingredient diosgenin was utilized as an organogelator for structuring canola oil. Results show that stable diosgenin-based organogel can be obtained at only 2% of diosgenin concentration when the gel preparation temperature is 100 °C. Oil binding capacity and rheological properties of the organogel were investigated. Results demonstrate that these two macroscopic characteristics of the organogels can be significantly modified by simply changing the gel preparation temperature or diosgenin concentration. When the preparation temperature was 120 °C and the diosgenin concentration higher than 4%, oil binding capacity of at least 90% were obtained. Furthermore, higher gel preparation temperature resulted in higher G′values of the diosgenin-based organogels. According to the results analyzed by polarized light microscopy, XRD and FT-IR, it can be found that the possible gelation mechanism of the diosgenin-based organogels is formation of supramolecular structures by self-assembly of diosgenin molecule crystals via hydrogen bonding interaction. Varying gel preparation conditions of the organogels lead to self-assembly of diosgenin molecules to form different microstructures. Therefore, diosgenin can be considered as a good organogelator for producing functional organogel from canola oil. The novel diosgenin-based organogel is expected to be widely used in bio-related fields such as food and pharmaceutical industries.