Mathematical modelling of mass transfer in food packaging systems : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Bioprocess Engineering at Massey University, Palmerston North, New Zealand
Food packaging is of critical importance for New Zealand food exports. One function of food packaging is to preserve the quality of food products during shipping and distribution, a key aspect of which is the control of mass transfer (in particular moisture). As such moisture transfer is an important consideration in the design of food packaging. However traditional food packaging selection has often involved a quantitative or “trial and error” approach. Mathematical models present a useful alternative, allowing changes to current system properties as well as the design of new systems to be investigated prior to physical testing. The objectives of this study were to: investigate the processes and considerations involved in food packaging selection, formulate mathematical models that can be used to predict moisture transfer in food packaging systems, and present potential applications for the developed mathematical models.
To obtain a broad understanding of food packaging, the properties of common packaging materials used in the food industry as well as current consumer and technological trends were reviewed. Considerations involved in food packaging selection were then investigated, including general considerations followed by a focus on mass transfer and barrier properties. It was found that, although theory allowing the quantitative selection of food packaging barrier properties is fairly comprehensive, it is common industry practice to select packaging qualitatively. This suggested that many food packaging systems are sub-optimised. Several phenomena not generally considered in food packaging selection were also investigated as required for the formulation of the mathematical models.
Review of literature revealed significant gaps regarding data of food packaging barrier properties. Therefore, to assist with the identification of specific applications for the mathematical models, a summary of the barrier property requirements of various food products was produced. As part of this work a table of the barrier properties of food packaging materials presented in a standard format was compiled.