Potential for solar dryer application for food processing in Botswana

Abstract

Solar drying is a process of utilizing energy from the sun to remove moisture from products, especially food. It is a process that prolongs the shelf life of the harvested products, reduces post-harvest losses and lowers transportation costs since the products become portable and can be easily packaged subsequent to drying. Additionally, solar drying improves the quality and quantity of food. Food preservation by use of solar dryers holds immense potential in the food processing industry in Botswana due to abundant solar irradiance. Solar drying methods that can be applied in Botswana include direct, indirect and the mixed type. The traditional open to sun drying or the direct method is the primary technique currently being applied. Of note is that traditional open sun drying has some disadvantages. More efficient and effective drying techniques such as indirect and mixed type are necessary to guarantee high quality and a constant supply of foods. This paper reviews the traditional drying technologies used in Botswana and explores potential modern solar drying technologies that can be used to substitute and or complement them