|M.Sc Student||Harris Limor|
|Subject||Structuring Edible Oils using Mixture of Medium-Chain and|
Very Long-Chain Saturated Fatty Acids
|Department||Department of Biotechnology and Food Engineering||Supervisor||Dr. Maya Davidovich-Pinh|
|Full Thesis text|
Fats and oils are important part of human nutrition since they are the source for essential fatty acids (FAs) needed for metabolic pathways and are an important source of energy due to their high energy density. They also play a crucial part in consumer satisfaction due to their role in food texture and flavor. Various studies implying on the negative health effect associated with the consumption of unsaturated trans and saturated FAs have been published, leading to search for healthier fat replacements. One possible solution is the use of oleogels, which are mixtures of liquid edible oil and structuring agent, leading to solidification of the oil, mimicking the trans and saturated fats texture effect. Oleogels provide a way to decrease the saturated FAs content while avoiding the use of trans fats by structuring the oil with a physical network, thus producing solid texture. The current research aims to examine the use of two different chain length FAs mixtures, namely lauric (LA) (12:0) and behenic (BA) (22:0) acids, as a structuring agents of edible oil. This research results suggest that the gelation temperature can be controlled by changing the ratio between the two FAs. In addition, the gelation process was found to depend mainly on the crystallization of BA in the mixture, thus suggesting that the larger molecular architecture play dominant role on the network formation. Similar BA-dominant behavior was also shown in the oil binding capacity (OBC) of the LA/BA mixture. In contrast to the gelation temperature and OBC, LA was found to significantly affect the mechanical performance of the LA/BA mixtures. More specifically, softer gels were obtained in the mixture in comparison to simple addition of each component contribution, thus presenting an antagonistic relation between the two components. The nano-structural analysis revealed the presence of individual reflection peaks of the two components in the mixture, thus suggesting independent crystallization of each FA. Therefore, it can be concluded that LA and BA creates separate nano-platelets which organize together and form the crystal network which stabilizes the gel. In conclusion, the current research provides the first attempt to study the potential use of mixtures of two fatty acids as structuring agents in order to fine-tune gel characteristics.