Demand for healthy foods has increased substantially over the recent years due to growth in the world population and unhealthy lifestyles. One approach that could help to address this problem is the development of structures that offer high volume to energy content ratio. Techniques that could offer the necessary microstructural engineering capability include: microfluidics and electrospinning. The aim of the work described in this thesis was to investigate the potential of these two techniques for application in food science. Food compatible materials were used to demonstrate the ability of these two techniques to generate bubbles and fibres. The material selection (polymer and solvent) process revolved around three fundamental principles: food biocompatibility, ease of processing and cost of material. The most suitable materials were found out to be natural polymers of low calorific value that have known to provide a pathway to manufacture food products with improved satiety index. Alginate was chosen as the primary material to generate porous foams of different sizes using a microfluidic T-junction device. This was accomplished by first generating monodisperse alginate microbubbles and then cross-linking them by calcium ions. Key parameters that affect bubble size and uniformity were also identified and the effects of bubble size on foam pore diameter were discussed. Electrospinning of ethyl cellulose and collagen to form fibres and scaffolds, respectively, constituted the bulk of the thesis with a comprehensive investigation into the process parameters (such as flow rate, applied voltage etc.). The control over fibre aspect ratio, with respect to processing parameters, was subjected to a detailed analysis consisting of optimization and reproducibility. The effect of solution concentration was also studied in detail. In addition, two new elements were introduced into the fibre generation process by customizing the electrospinning setup. Use of a glass needle and the effect of heat on fibre aspect ratio formed this part of the research. These detailed studies culminated in the development of a hybrid system that combined microfluidics and electrospinning techniques together for the first time. The result was the creation of structures using the aforementioned materials that exhibited properties specific to structures generated by each individual technique. The ability of this system to generate structures of different morphologies was discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:626489 |
| Date | January 2013 |
| Creators | Ahmad, B. S. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1416407/ |
Page generated in 0.0017 seconds