| The ultimate goal of this work was to analyze and design modified atmosphere (MA) packages for fresh fruits and vegetables. Bulk MA packaging systems is a means of extending the benefits of low {dollar}rm Osb2{dollar} and elevated {dollar}rm COsb2{dollar} controlled atmosphere storage to small volume and short term crops. An extensive analysis of the system was performed to identify key factors for the successful design of MA packages: crop respiration rate and respiratory quotient, and the required permeability and selectivity of the gas exchange device. It was shown that a combination of two highly permeable gas exchange devices with a large difference in selectivity could meet the permeability and selectivity requirements of various crops to create and maintain optimal MA. In addition, methods of permeability and produce respiration rate measurement determined under conditions that simulate MA packages were developed, and the permeability characteristics of diffusion devices such as polymeric and perforated membranes and their combination were determined. A design procedure for determining the surface area of the permeation device and a model to simulate the modification of the atmosphere in a package were developed and validated for various crops. Thus creating and maintaining optimal atmospheres in both {dollar}rm Osb2{dollar} and {dollar}rm COsb2{dollar} in bulk containers for fruits and vegetables is possible. Successful application of modified atmosphere in practice would, however, depend on prevention of excessive condensation, and alleviation of the effect of temperature abuse during handling and distribution of the produce. |
