Development of moisture isotherms for Momordica charantia and Carica papaya



Equilibrium moisture content, adsorption, isotherms, Mathematical model


Safe moisture of a product is important in drying of agricultural products to prevent it from deterioration. The equilibrium moisture content (EMC) is an important parameter in modeling and simulation of drying process. The objectives of the research are development of an EMC curve for Agricultural Products; bitter gourd (Momordica charantia) and papaya (Carica papaya) and to test the suitability of mathematical models of modified Henderson’s equations. The study is performed on the basis of adsorption of moisture content, at three temperatures (30, 40 & 50°C) and four relative humidity (Rh) (10, 30, 50 and 80%). Salt solutions with concentrations were used to maintain Rh. The statistical analysis was done to find the best model and the significant different between observed and calculated values were tested by coefficient of regression value and Reduced Chi squared test. EMC curve is developed for Bitter gourd and Papaya. The constants of mathematical models of Bitter gourd are estimated as N= 3.9, C=15.336 and K=1.05×10-7 and for Papaw as N= 15.3, C=13.75 and K=3.433×10-29. The modified Henderson’s equation was found to be the most appropriate model to describe the adsorption EMC isotherm equations of the given Agricultural products.


Author Biography

chintha Priyangani Rupasinghe, University of Ruhuna

Senior Lecturer,

Department of Agricultural Engineering






VI-Postharvest Technology and Process Engineering