Fish oil is an excellent source of long chain polyunsaturated fatty acids (LC-PUFA), which can reduce the risk of cardiovascular disease in addition to other health benefits. However, the average intake of LC-PUFA in the Western diet is much lower than the recommended levels. Fish oil is prone to oxidative deterioration when exposed to oxygen and thus must be protected in order to be used in food products. Microencapsulation is one possibility that is already applied by the industry to protect fish oil. However, most of the conventional microencapsulation techniques suffer from shortcomings such as harsh processing conditions or the use of numerous chemicals. The main objective of this thesis was to develop a novel spray process to microencapsulate fish oil based on supercritical fluid (SCF) technology using supercritical carbon dioxide (SC-CO2) and CO2-expanded ethanol (CX EtOH).
Fundamental physicochemical properties essential for optimal process design were lacking in the literature; therefore, density, interfacial tension (IFT) and viscosity of fish oil in the form of triglycerides and fatty acid ethyl esters were determined at different temperatures and pressures. Fish oil when equilibrated with SC-CO2 at elevated pressure expanded by up to about 40% in volume and increased in density by up to about 5%. Furthermore, IFT of fish oil in contact with SC-CO2 decreased substantially by an order of magnitude with an increase in CO2 pressure. When fish oil was in contact with CX EtOH, IFT decreased to ultra low levels at pressures of less than 10 MPa. Viscosity of fish oil equilibrated with SC-CO2 decreased substantially with pressure but increased with shear rate.
Based on the physicochemical properties determined in this research, a novel process to produce micro- and nano-sized particles containing fish oil was developed based on a SCF spray-drying method. Key processing parameters have been evaluated and can be further optimized to improve encapsulation efficiency.
Determination of physicochemical properties contributed to the fundamental understanding of the behavior of the fish oil+CO2 system with and without ethanol under high pressure conditions. The new microencapsulation process shows great potential for the delivery of bioactives in various product applications. / Bioresource and Food Engineering
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1139 |
| Date | 06 1900 |
| Creators | Seifried, Bernhard |
| Contributors | Temelli, Feral (Agricultural, Food and Nutritional Science), Vasanthan, Thava (Agricultural, Food and Nutritional Science), Bressler, David (Agricultural, Food and Nutritional Science), Yeung, Anthony (Chemical and Materials Engineering), Jessop, Philip G. (Chemistry, Queen's University) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 17735610 bytes, application/pdf |
| Relation | Seifried, B. and Temelli, F. (2009) Design of a high-pressure circulating pump for viscous liquids. Review of Scientific Instruments. 80: 075104 p.1-6., Seifried, B. and Temelli, F. (2009) Density of marine lipids in equilibrium with carbon dioxide. The Journal of Supercritical Fluids. 50: p. 97-104., Seifried, B. and Temelli, F. (2009) Interfacial tension of marine lipids in contact with high pressure carbon dioxide. The Journal of Supercritical Fluids. 52: p.203-214., Seifried, B. and Temelli, F. (2010) Unique properties of carbon dioxide expanded lipids. AOCS inform. January 2010., Seifried, B. and Temelli, F. (2010) Density of Carbon Dioxide Expanded Ethanol at (313.2, 328.2, and 343.2) K. Journal of Chem. Eng. Data, DOI: 10.1021/je900830s; Published (Web): March 29, 2010. |
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