Kinetika Pengeringan Lapisan Tipis Daun Jati Belanda (Thin Layer Drying Kinetics of Guazuma Ulmifolia Leaves)

Abstract

The objectives of this study were to determine a suitable thin layer drying model to describe the drying kinetics of Guazuma ulmifolia leaves and determine the mass transfer parameters of Guazuma ulmifolia leaves. The drying of Guazuma ulmifolia leaves was conducted in a laboratory scale dryer with various temperature (40oC, 50oC, and 60oC) and relative humidity (30%, 40%, 50% and 60%). Five drying models, namely, Newton, Henderson and Pabis, Page, Midilli-Kucuk, and Verma et al. were fitted to the drying data. The drying curve of guazuma leaves did not show a constant drying period during the drying period. The models suitability were compared base on coefficient of determination (R2), root square mean errors (RSME), and reduced mean square of deviation (X2). It was found that, among the models evaluated, the Midilli and Kucuk model is the best to describe the drying kinetics of Guazuma ulmifolia leaves. The effective moisture diffusivity was found to be in the range of 10-13 – 10-12 m2/s and the convective mass transfer coefficient was in the range of 10-9 – 10-10 m/s. The activation energy value was found to be 89.21 kJ/mol.

Drying kinetics, modelling and total flavonoid content of Phyllanthus niruri L. under different drying temperature

“…This value is included in the effective moisture diffusivity of food and leafy specimens (10 -12 to 10 -8 m/s 2 ) [21]. This finding follows the results of earlier investigations on the P. niruri and P. amarus herbs drying [8], purple basil leaves [13], and Guazuma ulmifolia leaves [14]. A temperature rise induces a lowering in water viscosity and fluid outflow resistance [18].…”

“…In addition, it had previously been reported that most products only experience a falling-rate period affected by heat and mass transfer rate, which causes moisture to move to the surface of the material, experiencing evaporation [18]. According to several studies on the drying of some herbal leaves, no steady drying rate was observed; instead, a falling-rate drying [11]; [18]; [13]; [14].…”

“…As previously mentioned, differences in the thickness of the slabs and the temperature range used affect the experimental results. Furthermore, the activation energy value of P. niruri is relatively lower compared to other leafy herbs, such as olive leaves at 75.98 kJ/mol [25] and Guazuma ulmifolia leaves at 89.21 kJ/mol [14].…”

“…However, in all drying temperature conditions, the model of Midilli-Kucuk seems to be the most proper model for graphing the kinetics of P. niruri drying. This model also best explains the kinetics of Guazuma ulmifolia leaves drying [14]. Meanwhile, the Logarithmic model resulted in an acceptable fit for drying betel leaves [9], basil leaves [15]; [19], and purple basil leaves [13].…”

Implementation of Arduino Uno-Based Temperature Control for Drying Kandis Acid (Garcinia xanthochymus)

“…(Rozana et al, 2016). The graph of the drying rate shows changes that are not constant, because at the beginning of drying there is no free water on the surface of the material (Syah et al, 2020). Two main factors that affect the drying process are the drying air factor and the material itself.…”