Designing and Experimenting a Greenhouse Dryer for Fruits, Vegetables and Spices

Curbing postharvest losses in fruits, vegetables and spices by drying has been a serious challenge due to limitations of open sun drying and high cost of mechanical dryers. In this study, a Greenhouse dryer (GHD) was designed, constructed and tested. Experiments were conducted using Completely Randomized Design (CRD ) to evaluate the performance of the GHD with fresh plantain, tomato and turmeric in comparison with open sun drying (OSD) under the same weather condition. Data collected were subjected to Multivariate Analysis of Variance (MANOVA) using the Statistical Analysis System (SAS) 2011 version 9.4 at 5% significant levels. The initial moisture contents of the products were reduced from 60%, 96% and 82% respectively wet base to final moisture contents 9%, 10% and 10% in 31hrs, 58hrs and 31hrs respectively. The average drying rates and the efficiency of the GHD are 0.024kg/hr, 0.030 kg/hr and 0.013kg/hr and 87%. The temperature of the GHD per hourly basis was significantly highest 50℃ and the relative humidity was significantly lowest 17%. The results showed that, the GHD performed satisfactory, improves drying conveniences and comfort and is beneficial to farmers in developing countries to curtail postharvest loss. Keywords: Design, Construction, Greenhouse Dryer, Instrumentation, Agricultural commodities