1Indonesian Center for Agricultural Engineering Research and Development, Tromol Pos 2, Serpong, Tangerang, Banten-15310, Indonesia
2Department of Agricultural Engineering, Faculty of Agricultural Technology, Gadjah Mada University, Jl. Sosio Justisia, Bulaksumur, Yogyakarta-55281, Indonesia
3Department of Agricultural Engineering, Bogor Agricultural University, PO Box 220, Bogor-16002, Indonesia
The objective of this work was done to investigate the effect of temperature and relative humidity on the equilibrium moisture content (EMC) of local cardamom (Amomum cardamomum Wild) and to get the appropriate mathematical models. The EMC of local cardamom were determined by dynamic method using laboratory air dryer at the temperature of 40, 50 and 60°C and at the relative humidity of 20, 40 and 60%. Four widely used three parameters sorption isotherms equations such as modified Henderson, modified Chung-Pfost, modified Oswin and modified Halsey were used to fit the experimental data. The accuracy of the model was evaluated by comparing the value of the coefficient of determination (R2) and the value of the root mean square error (RMSE) between the experimental and the predicted value of EMC by using nonlinear regression analysis. The effects of relative humidity were found to significantly influence the EMC. Based on statistical analysis the modified Chung-Pfost equation have the highest value of R2 = 0.979 and the lowest value of RMSE = 0.758, it can be seen that the modified Chung-Pfost equation has the ability to properly describe EMC of local cardamom on a selected range of temperature and relative humidity.
Equilibrium moisture content, dynamic methode, mathematical modelling, local cardamom
