Proximate and Mineral Analysis of Evaporative-Cooled Tomatoes

Abstract

Postharvest losses of tomatoes remain a major challenge in sub-Saharan Africa due to erratic power supply and inadequate storage systems. This study evaluated the effects of aluminium -in-pot evaporative cooling systems on the proximate composition, mineral content, and physiological weight loss of two tomato cultivars (UTC and Plum). The tomatoes were stored in five different Aluminium-in-pot evaporative (A, B, C, D and E) coolers and under ambient conditions (control). The proximate analysis was done using Association of Official Analytical Chemists (AOAC) methods, while mineral contents, lycopene, and vitamin C were determined using an atomic absorption spectrometer and titrimetric methods, respectively. Results showed that weight loss in the evaporative cooling system ranged from 2% to 9% as compared to the weight loss of the control case, which varied from 3.7% to 25%. The shelf life of tomatoes in evaporative cooler E was extended to 15 days, while for the control case, it lasted only 4 to 5 days. Additionally, evaporative cooling significantly reduced weight loss and rate of decay while improving retention of moisture, vitamin C, lycopene, and essential minerals relative to ambient. These findings demonstrate the effectiveness of evaporative cooling as a low-cost, sustainable technology for extending tomato shelf life and preserving nutritional quality, with potential applications in post-harvest storage system design.