Development and Performance Evaluation of a Modified Active Evaporative Cooling System for Postharvest Preservation of Selected Vegetables

• Shehu ABDULKADIR

  Author

• Dangora N. DAUDA

  Author

• Aliyu A. ADAMU

  Author

• Badaru M. SANI

  Author

• Rilwan ABUBAKAR

  Author

• Timothy A. TIMOTHY

  Author

• Uchechukwu M. AGBOM

  Author

• Abubakar S. ABUBAKAR

  Author

In developing countries, such as Nigeria, postharvest losses of Fruits and Vegetables (FV), especially tomatoes (Solanum lycopersicum), carrots (Daucus carota), and bell peppers (Capsicum annuum), are largely attributed to inadequate cold storage facilities (about 40 – 50%), as conventional refrigeration remains unaffordable for small-scale farmers. In this study, a modified, active direct evaporative cooler with an 8 m³ chamber was constructed using galvanized mild steel and aluminum. It comprised a suction fan of (183.1 m³/hr, 25 W, 1250 rpm), cooling pad (Jute) of 0.05 m thickness and water pump with discharge capacity of 30 l/min as well as a power rating of 0.5 HP. An overhead tank and water reservoir of capacity 500 L (0.5 m³) and 230 L (0.23 m³) respectively; were connected via PVC pipes to keep the pad continuously wet. The Study evaluated the shelf-life of tomatoes, carrots and peppers over 14 days by comparing the internal storage environment and the state of produce with the same produce stored in ambient conditions in triplicate. The modified cooler achieved an average cooling efficiency of 81% while maintaining the average storage system temperature of 25.6°C and a relative humidity of 76.2%, compared with the ambient averages of 35.8°C and 41.3%. Produce stored in the cooler showed significantly reduced physical weight loss, with satisfactory colour and firmness maintained for up to 14 days, as compared to 4-8 days under ambient conditions. A Student's T-test confirmed significant difference in the storage microenvironment and notable improvements in tomato, and pepper preservation. The analysis indicates that the modified evaporative cooler is an effective, cost-efficient technology for small-scale farmers, offering a practical solution to improve postharvest management, enhance food security, and support livelihoods.

• FJET_21_73_73

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