Optimization of Drying Temperature Distribution using CFD and Experimental Methods for Cape Gooseberry Drying

Abstract

This study aims to enhance the drying quality of cape gooseberries by addressing the non-uniform temperature distribution typically observed in traditional drying processes. Computational Fluid Dynamics (CFD) was employed to redesign the drying chamber by integrating a centrally positioned baffle duct to improve airflow distribution. Various hot air inlet velocities were simulated to optimize temperature uniformity. The CFD results indicated that an optimal inlet velocity of 3–5 m/s maintaining a consistent drying temperature between 59–60°C. This condition was applied in the actual construction of the drying chamber. Validation experiments showed that CFD-predicted temperatures deviated by less than 10% from measured values across all monitoring points. This confirms the reliability of the CFD. Following the validation, further experiments were conducted to evaluate drying quality of cape gooseberries. Additional factors such as pretreatment duration, ripeness, and drying method were investigated to determine their influence on product quality. Pretreatment duration and ripeness significantly affected drying efficiency and physiochemical properties. A 3-day pretreatment resulted in lower post-drying moisture content (MC) compared to a 5-day treatment, while less ripe fruits (Grade C) demonstrated suboptimal drying quality. Moreover, drying method and ventilation control also played a critical role. The first method, fully opening vents during the initial 6 hours, produced lower average MC and water activity (Aw) than the second method, partially opened the vents.