Thesis
Sodium chloride diffusion in selected low-acid foods during thermal processing
Washington State University
Master of Science (MS), Washington State University
2013
Handle:
https://hdl.handle.net/2376/102635
Abstract
Health risks from the excessive consumption of sodium have led to the need to reduce the sodium content of processed foods. Modeling the diffusion of sodium chloride (NaCl) in lowacid foods during thermal processing is desirable in efforts to reduce sodium in processed foods. Published literature on salt diffusion in solid food focused on temperatures below 100°C, which may not be applicable to salt diffusion at high temperatures. The main objective of this study was to expand the understanding of sodium chloride diffusion in low-acid foods during thermal processing over a temperature range of 90 to 121°C. Diffusion experiments were conducted at 90, 105, or 121°C with cylindrical samples of fresh potato, fresh radish, and frozen, thawed sockeye salmon immersed in 1 or 3% NaCl solutions for times varying from 5 minutes to 4 hours. These treatment times encompassed shorter, microwave assisted thermal sterilization processes (8 to 12 minutes) and longer, conventional thermal sterilization processes (30 to 200 minutes). Sodium chloride diffusion was modeled with these data using Fick’s second law solved analytically and numerically. COMSOL Multiphysics 4.2a was used to numerically model transient conductive and convective heat transfer and NaCl diffusive mass transfer in a two- v dimensional axisymmetric geometry. Results showed that the processing temperature, food matrix, and solution concentration all effect the final salt concentration in food. For most diffusion parameters, using dry basis concentration data made differences between foods more apparent than using wet basis data. Numerical and analytical solutions showed good agreement with experimental diffusion data. In the future, these experimental and modeling results can be utilized to optimize the amount of NaCl added to thermally processed, low-acid foods.
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Details
- Title
- Sodium chloride diffusion in selected low-acid foods during thermal processing
- Creators
- Ellen rose Bornhorst
- Contributors
- Juming Tang (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525395401842
- Language
- English
- Resource Type
- Thesis