Design and evaluation of a smart microclimate storage system for reducing postharvest losses in onion

Purpose This study investigates the impact of varying storage conditions specifically temperature and relative humidity on the postharvest quality of Dadin-kowa red onions. Methods Onions were stored under combinations of three temperature levels (25, 30, and 35°C) and three relative humidity levels (60, 65, and 70%) for 8 weeks. The parameters evaluated were weight loss, rottenness percentage, and total soluble solids (TSS). Results Results indicate that higher temperatures significantly increase weight loss and rottenness, while higher humidity tends to reduce weight loss but may increase spoilage risk at elevated temperatures. TSS values remained relatively stable across treatments. The findings suggest that moderate humidity (65%) and lower temperature (25°C) offer optimal storage conditions for minimizing postharvest losses in onions. Conclusion This study demonstrates how affordable, sensor-based storage systems can reduce onion postharvest losses and support food security initiatives in sub-Saharan Africa.