Physical quality analysis of drying beluntas leaves (Pluchea indica L.) using variations of drying methods

Abstract

Beluntas leaves are medicinal plants with pharmacological effects, such as antioxidant, antidiarrheal, antidiabetic, and antibacterial. Drying is one of the processes before the beluntas leaves are consumed. However, drying could degrade the quality of beluntas leaves. This research aims to investigate the impact of drying conditions on the physical qualities of dried beluntas leaves. Beluntas leaves with a moisture content of 83-90% were dried using drying methods, namely the greenhouse effect dryer (ERK), cabinet dryer (CD) at 40, 50, 60, and 70°C, and freeze dryer (FD) at 35, 45, and 55°C. The physical parameters measured were moisture content, color, shrinkage, rehydration ratio, and bulk density. The results showed that the final moisture content of the dried beluntas leaves were 8.40; 4.92-10.70; 4.73-6.77%w.b for ERK, CD, and FD, respectively. Page's model was suitable for explaining the changes in moisture ratio during the drying process (R 2 = 0.9934-0.9999). The freeze-drying method can preserve the leaves' color and obtain the lowest moisture content with a low drying temperature compared to other methods. Freeze-dried beluntas leaves also exhibited the highest rehydration ratio, which was 2.03-2.25.