Performance Evaluation of a Free-Energy Cooling Chamber for Reducing Post-Harvest Tomato Losses in Tropical Island Conditions: Evidence from Unguja, Zanzibar

Abstract

This study evaluated the effectiveness of Free Energy Cooling Chambers (FECC) in preserving postharvest tomatoes on Unguja Island, Zanzibar. The FECC created a cooler and more humid microclimate, reducing internal temperature by more than 8°C and increasing relative humidity by over 25% compared to ambient storage conditions.

Tomatoes stored in the FECC exhibited a shelf life of up to 15 days, significantly longer than those kept under ambient conditions. Weight loss was limited to less than 10% in the FECC, compared to more than 25% under non-cooled storage. In addition, tomatoes stored in the FECC retained higher nutritional quality, including lycopene and vitamin C content, while total soluble solids increased more gradually, indicating slower ripening. Vitamin C content in FECC-stored tomatoes reached a peak of 20 mg/100 g, whereas under ambient storage it declined to 13.5 mg/100 g by day 12, highlighting the importance of cool and humid conditions in preserving antioxidants.

Overall, the findings demonstrate that FECC technology is a low-cost, energy-independent solution capable of reducing postharvest losses and maintaining the biochemical integrity of tomatoes in resource-limited settings, thereby benefiting smallholder farmers.

Keywords: Free Energy Cooling Chamber (FECC); Postharvest preservation; Tomato quality; Vitamin C and lycopene retention; Tropical Island

DOI: 10.7176/JNSR/17-1-04

Publication date: February 28^th 2025