Mass transfer processes in food systems, such as solute infusion, are poorly understood
because of their complex nature. Food systems contain porous matrices and a variety of
continuous phases within cellular tissues. Mass transfer processes are generally not pure
diffusion: often convection, binding and obstructing diffusion will occur. Monte Carlo
(MC) simulation has been increasingly used in life science and engineering to elucidate
molecular transport in biological systems. However, there are few articles available
discussing MC simulation in food processing, especially mass transfer. The main goal of
this study was to show the inherent simplicity of the MC approach and its potential when
combined with traditional experimental and theoretical approaches to better describe and
understand mass transfer processes. A basic framework for MC random walk -
simulation applied to a diffusion problem - is developed in this project. Infusion of two
sizes of dextran macromolecules in fish muscle cells is used to apply the MC framework
in combination with Fluorescence Recovery After Photobleaching experiments. Effective
diffusivity coefficients within cells, considering the degree of obstruction due to the
myofibrilar matrix, are assessed. Then, the results are used as input in a mathematical
model that was developed for theoretical simulation of mass transfer in the multi-cellular
tissue. Diffusivity values obtained by the MC framework had an SD of ±0.02 [µm²/s]
around the true value of 0.25 [µm²/s]. MC results for degree of obstruction were 0.29 and
0.34 for dextran FD1OS and FD2OS, respectively, and the Devalues were 23.7 and 11.2
[µm2/s]. The statistical error in the estimation of D was estimated to be [22.8-24.6] and
[9.7-12.7] (95% CI), where average experimental values of 24.3 [µm²/s] for FD1OS and
11.4 [µm²/s] for FD2OS were captured by the respective interval. The theoretical model
showed a significant influence of the cell membrane characteristics and tissue porosity in
both the degree of solute penetration and the solute distribution between intra- and extra-cellular
space. The combined approach was successfully applied to a diffusion problem.
Overall, it is expected that the present work will contribute towards the application of
MC simulation in the field of Food Science and Engineering. / Graduation date: 2006
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28671 |
| Date | 15 July 2005 |
| Creators | Almonacid-Merino, Sergio Felipe |
| Contributors | Bolte, John |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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