Abstract: The objective of this research is to experimentally investigate the performance and drying kinetics of turmeric under three different conditions: solar drying with a solar air collector (SAC) in mixed mode, solar drying without a SAC in direct mode, and open sun drying. The study aims to evaluate the moisture reduction and drying time required for each condition. The experimental results demonstrate that a moisture reduction from 86% to 4% (wet basis) can be achieved within 8 hours using a solar dryer with a SAC. The Wang and Singh model exhibited the best fit for the thin-layer drying kinetics, showing the highest coefficient of determination (R2) value and the lowest chi-square (χ2) and root mean square error (RMSE) values. The model constant was determined through regression analysis. Comparing the drying performance, it was observed that drying turmeric in a solar dryer with a SAC resulted in effective drying time and better overall dryer performance compared to drying without the use of a SAC. This research contributes to understanding the drying behavior and performance of turmeric under different drying conditions. The findings highlight the advantages of solar drying with a SAC in terms of drying time and efficiency, offering a sustainable solution for turmeric drying in the region.

Keywords: Turmeric; NER; Direct mode; Mixed mode; Thin layer drying; Solar air collector.