Samenvatting

Tomato (Lycopersicon esculentum) is one of the important vegetables in Rwandese diet, since it is rich in health valued food components such as carotenoids (Lycopene), ascorbic acid (Vitamin C), vitamin E, folate and dietary fibers. The post harvest loss in tomatoes has been estimated to be about 20-30% at farmer level due to inadequate post harvest handling, lack of infrastructure, processing technologies, marketing and storage facilities. “SORWATOM -” a tomato processing plant located in Kigali has poor linkages with tomatoes farmers resulting in unreliability of supply in terms of quantity and quality and this translates into high postharvest losses to the farmers. Though sun drying has been used in Rwanda for drying agricultural products for reducing moisture content and extending shelf life, it is a slow process and the quality of the dried product is often inferior due to contaminations. Therefore a cabinet hybrid dryer, using solar energy and biomass furnace was tried to increase the shelf life of tomatoes and to minimize these losses. During drying, it was observed that the temperature inside the solar hybrid cabinet dryer was 70 ºC when the maximum ambient temperature was only 27 ºC. The tomato slices of between 6 and 8 mm thicknesses were dried from 94 to 9 % moisture content for an average time of 12 hours. The weight and volume of tomatoes was decreased by 92 %. It was found that the drying process could allow the extension of the shelf life of tomatoes by reducing the moisture content and thus the product weight and volume, and was a relatively low cost and simple technology that could be addressed to the crucial problem of postharvest losses in tomato in Rwanda. Drying produce in harvest seasons where the prices are low and selling in off-seasons where prices are high can be a good opportunity for tomatoes farmers to improve their income. Therefore this technology almost unknown in Rwanda was strongly recommended as one of the most promising alternatives to reduce post harvest losses.