Solar Assisted Pervaporation (SAP) for Preserving and Utilising Fruits in Developing Countries

This project looks at a new technology for fruit preservation in rural and remote areas. A bag consisting of a breathable membrane is filled with fruit juice/puree, sealed and placed in the sun. Within a few days, enough water has escaped from the semi-permeable membrane as vapour that a shelf-stable concentrate remains. A theoretical framework for the technology is still needed and so the aim of the doctoral project is to obtain a deeper understanding of the heat and mass transfer taking place, both inside and outside the bag, using a mathematical modelling approach.

Is it reasonable that enough food is grown to feed the entire world population, yet many still go hungry? The aim of this project is to develop a simple and affordable technology for preserving fruits at their peak time of ripening to be consumed at a later time in the year. The technology is a breathable bag that can be filled with fruit juices/purees and put in the sun to dry. Water passes through the bag but the rest of the nutrients remain inside. Once enough water has been removed, the natural sugars in the fruit can then preserve the product. The technology is especially useful in developing countries where fruit is abundant but fruit processing factories are not available. Mathematical modelling can be used to better understand how the technology works and how long the drying process should take place. The doctoral project will focus on developing these mathematical models so the end user knows when to stop the process.