ABSTRACT

This research investigated how the drying-conditions affect drying-performance of Cut-Roselle (Hibiscus_sabdariffa L.). The experiments are conducted using Constant-Temperature-Humidity-Chamber, where varied temperatures (35,45,55,65°C) and relative humidity levels (30,35,40,45,50%) are tested. The drying process for Cut-Roselle primarily occurred during the falling-rate-period. Notably, the drying-air temperature significantly, influenced the drying-kinetics, with higher temperatures (ranging from 35 to 65°C) resulted in shorter drying-times. Relative-humidity had a lesser-impact compared to the temperature. Extended drying-periods and increased equilibrium moisture levels are observed under conditions of elevated relative-humidity and reduced temperatures. An evaluation of various thin-layer drying-models is conducted to determine the most accurate model for the drying-characteristics. The Modified-Page II model demonstrated exceptional fit quality, with R2=0.99949. It effectively described the dehydration-behavior of Cut-Roselle within the range of the experimental drying-parameters.