7 November 2003
For the year 2002-2003 I was the Seligman APV bursary holder for research in food engineering. This made it possible for me to travel from New Zealand to the United Kingdom to undertake research and visit centres of research such as Syngenta and Unilever.
For the past year, I have been employed as a post-doctorate researcher at the Chemical Engineering Department at the University of Cambridge, undertaking a project sponsored by the Engineering and Physical Sciences Research Council (EPSRC).
The project title was Visualising the crystallisation of single droplets of food and pharmaceutical materials with magnetic resonance imaging (MRI). The objectives were to explore the capabilities of MRI at observing and quantifying microstructural development within freezing droplets.
The freezing of single droplets is related to the process of spray freezing. This technique is a relatively new method for generating particulate solids from food or other solutions. It involves spraying small droplets of aqueous solutions or slurry into a cold, dry atmosphere, which promotes rapid cooling, and solidification of the droplet. The resulting particles, whose sizes can be closely controlled, can be added directly to refrigerated or frozen products (e.g. as part of an ice-cream recipe) or subsequently freeze-dried under vacuum to yield particles.
Our interest in this technology was to investigate unique microstructures accessible by this route that may yield attributes such as flavour enhancement and retention which are not attainable via conventional freezing techniques.
The project was also innovative in its application of MRI. It had never been applied to bodies of liquids of the size of droplets investigated and at time scales associated with droplet freezing.
It was proven to be a very successful project. The results demonstrated that MRI is a valuable method of analysing the microstructural development within freezing droplets and it was possible to observe distinctive structure formation within droplets. It was concluded that the microstructure formation within droplets could be manipulated to change functional properties of a powder produced by spray freezing. These results have generated six journal publications and two conference articles.
Visits and Collaborations
One of the objectives of the Seligman APV Bursary is to promote exchange of information and personal contact between all those interested in food engineering. Over the year have visited the following centres within the UK:
- Reading University
- University of Loughborough.
During these visits, I have presented my work and assisted with building collaborations with the University of Cambridge. These visits were very valuable as I was able to see manufacturing and research facilities of a quality and scale not present in New Zealand. Also, having been actively involved in the development of industry collaborations and funding applications has broadened my professional skills, which will be invaluable in my future of engineering research.
Furthermore, I attended the SCI 2002 and 2003 annual meetings. At the 2003 meeting, I presented a portion of my research work.
A significant outcome of my experience in the UK is that I have been awarded a three year post-doctoral fellowship from the Foundation for Research, Science & Technology (FRST) in New Zealand. The technical and professional skills I gained in the UK directly contributed to this. Furthermore, the research has trained me in magnetic resonance imaging, which is a major part of the post-doctoral fellowship research project. In addition to this, the experience of being involved in the preparation of funding applications and developing collaborations with industry gave me the skills and confidence to successfully apply for this post-doctoral funding.