The drying rate shows the falling rate phase characterised by a fast or rapid initial rate. This is a constant drying rate phase. This is indicative of diffusion as the most significant process governing the rate of internal moisture migration to the surface for evaporation. It was observed that the initial drying rate was 0.164 kg water/h and at the end of the test run the drying rate fell to 0.066 kg water/h The inconsistence shown between the hours of 6 and 8 is due to the fact that after the 6th hour solar drying was stopped and the product was left overnight under ambient conditions for drying the next day. Initial rate is high due to removal of surface and free moisture. Resumption of the drying process saw an increase in drying rate due to increased moisture availability at the surface from overnight internal moisture migration to the surface. After this the rate falls again as migration of internal moisture to the surface is affected by both the rate of diffusion and `case hardening. As the drying progresses, the evaporation rate decreases, with less evaporative cooling, and the product’s internal temperature increases. Decolourisation and formation of off-flavours may occur with high internal temperatures towards the end of the drying process. This was the reason for the use of a thermostat to regulate the temperature to below 60C. Quality issues such as any changes in colour, taste, flavour and drying rates between solar-dried and oven-dried tomatoes are compared in Table 2 below, and the weight in kg per batch dried in a given time are shown as indications of drying rates (Table 2 below).