Evaluation of the performance of an evaporative cooling structure on the shelf life of stored tomatoes in Morogoro region, Tanzania

Abstract

The losses on perishables have been a challenge in most developing countries. The current status is critical and its control for small scale farmers and retailers has not been adequately addressed. The lack of simple storage facilities in the tomato supply chain contributes to high postharvest losses of tomatoes in Tanzania. The aim of this study was to design an evaporative cooling structure for the storage and shelf-life extension of tomatoes. An Improved wind operated passive evaporative cooler (IWOPEC) was developed and its performance was evaluated. The experimental design was a Randomized Complete Block Design (RCBD). The storage environment conditions considered were ambient (AT), cold room (CR), and IWOPEC structure. The results on the effects of temperature and relative humidity (RH) were significantly different (p<0.05) under the studied storage environments and time. Total soluble solids and percentage weight loss significantly increased (p<0.05) for all studied environmental conditions, whereas firmness and titratable acid significantly decreased (p<0.05) in response to storage time and studied environmental conditions. The IWOPEC structure reduced temperature, increased RH, and gave peak and daily average cooling efficiency of 84.89% and 61.67%, respectively. In areas with high PHLs under AT, using the IWOPEC structure to improve shelf life of tomatoes is economically feasible. Improvement of the IWOPEC structure by having a water boot sump and a water pump to increase the cooling efficiency of the storage atmosphere is recommended.