OIL STRUCTURING USING A FOOD GRADE POLYMER: ETHYL-CELLULOSE

The use of oleogels as a way to structure liquid oil has been examined extensively over the past decade for various applications. Several strategies have been developed in order to produce oleogels based on the nature of the gelator used. Ethyl-cellulose ability to structure oil was first introduced in the early 1990’s and up to date it is the only polymer oil gelator that can be found in the literature. Our research aims to study the EC oleogel structure and properties with an emphasis to understand the structure-function relation for food applications. The characterization of the thermo-gelation mechanism and properties of EC/canola oil oleogels was performed using rheological, mechanical and thermal analysis. The sol-gel transition was studied using temperature and frequency sweep experiments as well as differential scanning calorimetry (DSC). The involvement of intermolecular hydrogen bonds in the formation of the EC network was confirmed using attenuated total reflection (ATR) analysis in addition to a rheological approach where the effect of increasing temperature on the gel storage modulus was examined. The role of hydrogen bonds in the formation of the physical network was further examined using different setting gelation temperatures. It was found that stronger gels were consistently produced when using higher gelation setting temperatures (>60°C). The effect of solvent quality and addition of small active surface molecules was also examined. Higher solvent polarity and addition of small active molecules produced strnger gels. This research provides a conclusive insight into the gelation mechanism of ethylcellulose/canola oil oleogels. Such understanding could potentially contribute to further development of EC oleogel by altering its network structure and properties for varied applications such as food, pharmaceutical or cosmetics products.