Dehydration Characteristics of Whole Lemons in a Convective Hot Air Dryer

Document Type : Research Article


1 Department of Mechanical Engineering of Biosystems, Shahrekord University, Shahrekord, I.R. IRAN

2 Department of Biosystems Engineering, College of Agriculture, Isfahan University of Technology, P.O. Box 84156-83111 Isfahan, I.R. IRAN

3 Department of Chemical Engineering, Isfahan University of Technology, P.O. Box 84156-83111 Isfahan, I.R. IRAN


In this study, whole lemons were dried using a laboratory convective hot air dryer and the effects of drying temperature on dehydration behaviour and mass transfer characteristics of the lemons were investigated. The drying experiments were conducted using air temperatures of 50, 60 and 75 °C and air velocity of 1 m/s. It was observed that the drying temperature affected the drying time and the drying rate significantly. Drying rate represented no constant period and the entire dehydration process took place in the falling rate period. The usefulness of five mathematical models to simulate the drying kinetics was evaluated and Midilli and logarithmic models were found as the best models describing the drying curves. The effective moisture diffusivity values were obtained to be 1.15×10-10, 2.29×10-10, and 7.63×10-10 m2/s for the applied temperatures, respectively. The activation energy was also determined to be 71.32 kJ/mol. The convective mass transfer coefficient values were calculated by the analytical model and obtained to be 4.078×10-7, 1.023×10-7 and 4.346×10-8 m/s for drying temperatures of 75, 60 and 50 °C, respectively.


Main Subjects

[1] Esfahani J.A., Majdi H., Barati E., Analytical Two-Dimensional Analysis of the Transport Phenomena Occurring During Convective Drying: Apple Slices, J. Food. Eng., 123:87-93 (2014).
[2] Motevali A., Abbaszadeh A., Minaei S., Khoshtaghaza M.H., Ghobadian B., Effective Moisture Diffusivity, Activation Energy and Energy Consumption in Thin-Layer Drying of Jujube (Zizyphus jujube Mill), J. Agr. Sci. Tech. (JAST), 14:523-32 (2012).
[3] Torki-Harchegani M., Ghanbarian D., Sadeghi M., Estimation of Whole Lemon Mass Transfer Parameters During Hot Air Drying Using Different Modelling Methods, Heat. Mass. Transfer., doi: 10.1007/s00231-014-1483-1 (2014).
[4] Ghasemi Pirbalouti A., Oraei M., Pouriamehr M., Solaymani Babadi E., Effects of Drying Methods on Qualitative and Quantitative of the Essential Oil of Bakhtiari Savory (Satureja bachtiarica Bunge.), Ind. Crops. Prod., 46:324-327 (2013).
[5] Sadeghi M., Mirzabeigi Kesbi O., Mireei S.A., Mass Transfer Characteristics During Convective, Microwave and Combined Microwave-Convective Drying of Lemon Slices, J. Sci. Food. Agr., 93(3):471-478 (2013).
[7] Torki-harchegani M., Ghasemi-Varnamkhasti M., Ghanbarian D., Sadeghi M., Tohidi M., Dehydration Characteristics and Mathematical Modelling of Lemon Slices Drying Undergoing Oven Treatment, Heat. Mass. Transfer., 52(2): 281-289 (2015).
[8] Honarvar B., Mowla D., Safekori A.A., Physical Properties of Green Pea in an Inert Medium FBD Dryer Assisted by IR Heating, Iran. J. Chem. Chem. Eng. (IJCCE), 30(1):107-118 (2011).
[9]  Torki-Harchegani M., Moheb A., Sadeghi M., Tohidi M., Naghavi Z., Experimental Study of Deep-Bed Drying Kinetics of Rough Rice, Agric. Eng. Int. (CIGR J), 14(4):195-202 (2012).
[10] Brasiello A., Adiletta G., Russo P., Crescitelli S., Albanese D., Di Matteo M., Mathematical Modelling of Eggplant Drying: Shrinkage Effect, J. Food. Eng., 114(1):99-105 (2013).
[11] Duc L.A., Han J.W., Keum D.H., Thin Layer Drying Characteristics of Rapeseed (Brassica napus L.), J. Stored. Prod. Res., 47(1):32-38 (2011).
[13] Singh N.J., Pandey R.K., Convective Air Drying Characteristics of Sweet Potato Cube (Ipomoea batatas L.), Food. Biprod. Process., 90(2):317-322 (2012).
[14] Lemus-Mondaca R.A., Zambra C.E., Vega-Gálvez A., Moraga N.O., Coupled 3D Heat and Mass Transfer Model for Numerical Analysis of Drying Process
in Papaya Slices
, J. Food. Eng., 116(1):109-117 (2013).
[15] Akhondi E., Kazemi A., Maghsoodi V., Determination of a Suitable Thin Layer Drying Curve Model for Saffron (Crocus sativus L) Stigmas in an Infrared Dryer, Sci. Iran. (part C)., 18(6):1397-1401 (2011).
[16] Amiri Chayjan R., Tabatabaei Bahrabad S.M., Rahimi sardari F., Modelling Infrared-Convective Drying of Pistachio Nuts Under Fixed and Fluidized Bed Conditions, J. Food. Process. Preserv., 38(3): 1224-1233 (2013).
[17] Food and Agricultural Commodities Production, (2011).
[18] Torki-Harchegani M., Sadeghi M., Moheb A., Naghavi Z., Investigation on Rough Rice Drying Kinetics at Various Thin Layers of a Deep Bed, Heat. Mass. Transf., 50(12):1717-1725 (2014).
[20] Sadeghi M., Ashtiani Araghi H., Hemmat A., Physico-Mechanical Properties of Rough Rice (Oryza sativa L.) Grain as Affected by Variety and Moisture Content, Agr. Eng. Int. (CIGR J), 12(3):129-136 (2010).
[21] Zakipour E., Hamidi Z., Vacuum Drying Characteristics of Some Vegetables, Iran. J. Chem. Chem. Eng. (IJCCE), 30(4):97-105 (2011).
[22] Abbaszadeh A., Motevali A., Ghobadian B., Khoshtaghaza M.H., Minaei S., Effect of Air Velocity and Temperature on Energy and Effective Moisture Diffusivity for Russian Olive (Elaeagnusan gastifolial L.) in Thin-Layer Drying, Iran. J. Chem. Chem. Eng. (IJCCE), 31(1):75-79 (2012).
[23] Xiao H.W., Pang C.L., Wang L.H., Bai J.W., Yang W.X., Gao Z.J., Drying Kinetics and Quality of Monukka Seedless Grapes Dried in an Air-Impingement Jet Dryer, Biosyst. Eng., 105(2):233-240 (2010).
[24] Pacheco-Aguirre F.M., Ladrón-González A., Ruiz-Espinosa H., García-Alvarado M.A., Ruiz-López I.I., A Method to Estimate Anisotropic Diffusion Coefficients for Cylindrical Solids: Application
to the Drying of Carrot,
J. Food. Eng., 125:24-33 (2014).
[25] Demiray E., Tulek Y., Drying Characteristics of Garlic (Allium sativum L) Slices in a Convective Hot Air Dryer, Heat. Mass. Transf., 50(6):779-786 (2014).
[26] Kaya A., Aydin O., Demirtas C., Concentration Boundary Conditions in the Theoretical Analysis of Convective Drying Process, J. Food. Process. Eng., 30(5):564-577 (2007).
[27] Doymaz I., Thin-Layer Drying Characteristics of Sweet Potato Slices and Mathematical Modelling, Heat. Mass. Transf., 47(3):277-285 (2011).
[28] Kaya A., Aydin O., Dincer I., Comparison of Experimental Data with Results of Some Drying Models for Regularly Shaped Products, Heat. Mass. Transf., 46(5):555-562 (2010).
[29] Corrêa P.C., Oliveira G.H.H., Botelho F.M., Goneli A.L.D., Carvalho F.M., Mathematical Modelling and Determination of Thermodynamic Properties of Coffee (Coffea arabica L.) During the Drying Process, Revista. Ceres., 57(5):595-601 (2010).
[30] Tulek Y., Drying Kinetics of Oyster Mushroom (Pleurotus ostreatus) in a Convective Hot Air Dryer, J. Agr. Sci. Tech. (JAST), 13(5):655-664 (2011).