Mass Transfer, Energy-Exergy Analysis, and Mathematical Modeling of Chili Pepper During Drying

Document Type : Research Article


1 Biochemical and Bioenvironmental Laboratory, Department of Chemical Engineering, Ladoke Akintola University of Technology, Ogbomoso, NIGERIA

2 Process System Engineering Laboratory, Department of Chemical Engineering, Ladoke Akintola University of Technology, Ogbomoso, NIGERIA

3 Separation Processes/Unit Operation Laboratory, Department of Chemical Engineering, Ladoke Akintola University of Technology, Ogbomoso, NIGERIA

4 Federal Institute of Industrial Research, Oshodi, Lagos, NIGERIA


There are no literature data on the effects of air velocity and relative humidity on moisture diffusivity, mass transfer coefficient, and energy-exergy analysis of chili pepper during cabinet-tray hot-air drying. This study tends to address this gap by presenting comprehensive drying kinetic, energy, and exergy analyses of a cabinet-tray hot-air drying for red chili pepper. Drying was conducted at varying levels of air temperature (40-70 oC), air velocity (0.5-2.0 m/s), and relative humidity (60-75%). The effect of drying conditions on drying time, drying coefficient, lag factor, drying efficiency, moisture ratio, effective moisture diffusivity, mass transfer coefficient, total energy consumption (TEC), specific energy consumption (SEC), energy utilization ratio (EUR), heat loss, energy efficiency, exergy loss, exergy efficiency, exergetic improvement potential (EIP), and exergy sustainability index (ESI)) was evaluated. Five different mass transfer models (Dincer-Dost, Bi-Di, Bi-S, Bi-G, and Bi-Re) were applied to determine the mass transfer parameters. A new drying mathematical model was developed for the prediction of drying kinetic, energy, and exergy parameters. Effective moisture diffusivity values of 1.58×10–8 - 5.10×10–8 m2/s and mass transfer coefficient values of 0.053×10–6 - 8.79×10–6 m/s over the drying conditions range were respectively obtained. The TEC, SEC, and EUR achieved over the range of drying conditions in the course of drying were in the range of 43.56-77.36 MJ, 49.0-87.02 MJ/kg, and 0.035-0.325, respectively. Heat loss and exergy loss varied from 0.16 to 2.39 MJ and from 0.026 to 0.622 kW, respectively. Drying, energy, and exergetic efficiency values obtained varied in the range of 2.80-8.25%, 2.69-7.91%, and 73-94.5%, respectively. EIP and the ESI values varied from 0.0068-0.114 kW and 3.70-18.18, respectively. The developed multivariate linear regression model provided an innovative model to predict drying kinetic, energy, and exergy parameters.


Main Subjects

[1] Olatunji T. L., Afolayan A. J., The Suitability of Chili Pepper (Capsicum Annuum L.) for Alleviating Human Micronutrient Dietary Deficiencies: A review, Food Sci. Nutri., 6(8): 2239-2251 (2018).
[2] Giuffrida D., Dugo P., Torre G., Bignardi C., Cavazza A., Corradini C., Dugo G., Characterization of 12 Capsicum Varieties by Evaluation of their Carotenoid Profile and Pungency Determination, Food Chem., 140: 794-802 (2013).
[4] Mihindukulasuriya S. D. F., Jayasuriya H. P. W., Drying of Chilli in A Combined Infrared and Hot Air Rotary Dryer, J. Food Sci. Technol., 52(8): 4895–4904 (2015).
[5] Tunde-akintunde T.Y., Afolabi, T.J., Drying of Chili Pepper (Capscium frutscens). J. Food Proc. Eng., 33(4): 649-660 (2010).
[6] Saengrayap R., Boonlap N., Boonsorn U., Effect of Pre-Treatment Methods on the Color Changes during Drying of Red Chilli (Capsicum frutescens L.), Proc. of MATEC Web of Conferences 62: 02009 (2016).
[7] Montoya-Ballesteros L.C., Gonz´alez-Le´on A., Mart´ınez-N´u˜nez Y.J., Robles-Burgue˜no M.R., Garc´ıa-Alvarado M.A., Rodr´ıguez-Jimenes G. C., Impact of Open Sun Drying and Hot Air Drying on Capsaicin, Capsanthin, and Ascorbic Acid Content in Chiltepin (Capsicum Annuum L. Var. Glabriusculum), Revista Mexicana de Ingeniería Química, 16(3): 813-825 (2017).
[8] Artnaseaw A., Theerakulpisut S., Chatchai B., Development of a Vacuum Heat Pump Dryer for Drying Chilli, Biosystem Eng., 105: 130-138 (2010).
[9] Tavakolipour H., Mokhtarian M., Drying of Chilli Pepper in Various Conditions, Quality Assur. Saf. Crops & Foods, 8(1): 87-93 (2015).
[10] Mihindukulasuriya S.D.F., Jayasuriya H.P.W., Mathematical Modeling of Drying Characteristics of Chilli in Hot Air Oven and Fluidized Bed Dryers, Agric Eng Int CIGR J., 15: 154–166 (2013).
[11] Agrawal S.G., Methekar R. V., Mathematical Model for Heat and Mass Transfer during Convective Drying of Pumpkin, Food Bioprod Process., 101: 68-73 (2016).
[12] Salehi F., Kashaninejad M., Modeling of Moisture Loss Kinetics and Color Changes in the Surface of Lemon Slice during the Combined Infrared-Vacuum Drying, Informat. Process Agric., 5(4): 516 – 523 (2018).
[14] Khanali M., Banisharif A., Rafiee S., Modeling of Moisture Diffusivity, Activation Energy and Energy Consumption in Fluidized Bed Drying of Rough Rice, Heat Mass Transf., 52: 2541-2549 (2016).
[13] Md Saleh R., Kulig B., Hensel O., Sturm B., 1nvestigation of Dynamic Quality Changes and Optimization of Drying Parameters of Carrots (Daucus carota var. laguna), J. Food Proc. Eng., e13314 (2019).
[16] Mohammadi I., Tabatabaekoloor R., Motevali A., Effect of Air Recirculation and Heat Pump on Mass Transfer and Energy Parameters in Drying of Kiwifruit Slices, Energy, 170: 149–158 (2019).
[17] Akpinar E.K., Dincer, I., Application of Moisture Transfer Models to Solids Drying, Proc. IMechE J. Power Energy, 219 Part A: 235-244 (2005).
[19] Darvishi H., Asl A.R., Asghari A., Azadbakht M., Najafi G., Khodaei J., Study of the Drying Kinetics of Pepper, J. Saudi Soc. Agric. Sci., 13: 130-138 (2014).
[20] Beigi M., Energy Efficiency and Moisture Diffusivity of Apple Slices During Convective Drying, Food Sci. Technol., 36(1): 145-150 (2016).
[21] Darvishi H., Zarein M., Farhudi Z., Energetic and Exergetic Performance Analysis and Modeling of Drying Kinetics of Kiwi Slices, J. Food Sci. Technol., 53(5): 2317–2333 (2016).
[22] Tunde-Akintunde T.Y., Effect of Pretreatments on Drying Characteristics and Energy Requirements of Plantain (Musa Aab). J. Food Proc. Preserv., 38: 1849-1859 (2014).
[23] Torki Harchegan M., Sadeghi M., Ghanbarian D., Moheb A., Dehydration Characteristics of Whole Lemons in a Convective Hot Air Dryer, Iran. J. Chem. Chem. Eng. (IJCCE), 35 (3): 65-73 (2016).
[24] Ju H.-Y., El-Mashad H. M., Fang X.-M., Pan Z., Xiao H.-W., Liu Y.-H., Gao Z.-J., Drying Characteristics and Modeling of Yam Slices under Different Relative Humidity Conditions, Drying Technol., 34(3): 296–306 (2016).
[25] Abbaszadeh A., Motevali A., Ghobadian B., Khoshtaghaza M.H., Minaei S., Effect of Air Velocity and Temperataure 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).
[26] Zakipour E., Hamidi Z., Vacuum Drying Characteristics of Some Vegetables, Iran. J. Chem. Chem. Eng. (IJCCE), 30(4): 97-105 (2011).
[27] Erbay Z., Icier F., Energy and Exergy Analyses on Drying of Olive Leaves (olea europaea l.) in Tray Drier, J. Food Proc. Eng., 34: 2105–2123 (2011).
[28] Castro M., Román C., Echegaray M., Mazza G., Rodriguez R., Exergy Analyses of Onion Drying by Convection: Influence of Dryer Parameters on Its Performance, Entropy, 20: 310-314 (2018).
[29] Lingayat A., Chandramohan V.P., Raju V.R.K., Energy and Exergy analysis on Drying of Banana using Indirect Type Natural Convection Solar Dryer, Heat Transfer Eng., 41(6-7): 551-561 (2020).
[31] Akpinar E.K., Energy and Exergy Analyses of Drying of Red Pepper Slices in Convective Type Dryer, Int. Comm. Heat Mass Transf., 31(8): 1165–1176 (2004).
[32] Corzo O., Bracho N., Vasquez A., Pereira, A., Energy and Exergy Analyses of Thin Layer Drying of Coroba Slices, Food Eng., 86(2): 151–161 (2008).
[33] Folayan J. A., Osuolale F. N., Anawe A. L., Data on Exergy and Exergy Analyses of Drying Process of Onion in a Batch Dryer, Data in Brief, 21: 1784-1793 (2018).
[34] Nazghelichi T., Kianmehr M., Aghbashlo M., Thermodynamic Analysis of Fluidized Bed Drying of Carrot Cubes, Energy, 35(12): 4679-4684 (2010).
[35] Rabha D., Muthukumar, D., Somayaji C., Energy and Exergy Analyses of the Solar Drying Processes of Ghost Chilli Pepper and Ginger, Renew. Energy, 105: 764-773 (2017).
[37] Deng L.-Z., Yang X.-H., Mujumdar A. S., Zhao J.-H., Wang D., Zhang Q., Xiao H.-W., Red Pepper (Capsicum Annuum L.) Drying: Effects of Different Drying Methods on Drying Kinetics, Physicochemical Properties, Antioxidant Capacity, and Microstructure, Drying Technol., 36(8): 893-907 (2018).
[38] Kumara V., Shrivastava, S.L., Vacuum-Assisted Microwave Drying Characteristics of Green Bell Pepper, Int. J. Food Studies, 6: 67-81 (2017).
[40] Pavani S., Vani V.S., Dorajee Rao A.V.D., Viji C.P., Suneetha D.R.S., Subbaiah K.V., Kiran Kumar G.N., Sarada P., Influence of Pre-Treatments and Drying Methods on Physico-Chemical Characteristics of Green Chilli Powder, Int. J. Pure App. Biosci., 6(2): 1148-1152 (2018).
[41] Kamal M.M., Ali M.R., Rahman M.M., Shishir M.R.I, Yasmin S., Sarker Md.S.H., Effects of Processing Techniques on Drying Characteristics, Physicochemical Properties and Functional Compounds of Green and Red Chilli (Capsicum annum L.) Powder, J. Food Sci. Technol., 56: 3185–3194 (2019).
[42] Mondal Md. H.T., Hossain Md. A., Sheik Md. A.M., Akhtaruzzaman Md., Sarker Md.S.H., Energetic and Exergetic Investigation of a Mixed Flow Dryer: A Case Study of Maize Grain Drying, Drying Technol., 1-16 (2020).
[43] Kaveh M., Karami H., Jahanbakhshi A., Investigation of Mass Transfer, Thermodynamics, and Greenhouse Gases Properties in Pennyroyal Drying, J. Food Proc. Eng., e13446 (2020).
[45] Dincer I., Sahin A.Z., A New Model for Thermodynamic Analysis of a Drying ProcessInt. J. Heat Mass Transf., 47(4): 645-652 (2004).
[47] Pankaew P., Janjai S., Nilnont W., Phusampao C., Bala B.K., Moisture Desorption Isotherm, Diffusivity and Finite Element Simulation of Drying of Macadamia Nut (Macadamia integrifolia), Food Bioprod. Process., 100: 16–24 (2016).
[48] Taheri-Garavand A., Meda V., Drying Kinetics and Modeling of Savory Leaves Under Different Drying Conditions, Int. Food Res. J., 25(4): 1357-1364 (2018).
[49] Agarry S.E., Osuolale F.N., Agbede O.O., Ajani A.O., Afolabi T.J., Ogunleye O.O., Ajuebor F., Owabor C.N., Transport Phenomena, Thermodynamic Analyses, and Mathematical Modelling of Okra Convective Cabinet-Tray Drying at Different Drying Conditions, Eng. & Appl. Sci. Res., 48(5): 637-656 (2021).
[50] Herman C., Spreutels L., Turomzsa N., Konagano E. M., Haut B., Convective Drying of Fermented Amazonian Cocoa Beans (Theobroma Cacao Var. Forasteiro). Experiments and Mathematical Modeling, Food Bioprod. Process., 108: 81-94 (2018).
[51] AOAC, (Association of Official Analytical Chemists). “Official Methods of Analysis”. 16th ed. Washington DC, pp. 202 (2015).
[52] Dincer I., Dost S. A., Modelling Study for Moisture Diffusivities and Moisture Transfer Coefficients in Drying of Solid Objects, Int. J. Energy Res., 20: 531-539 (1996).
[53] Akpinar E. K, Toraman S., Determination of Drying Kinetics and Convective Heat Transfer Coefficients of Ginger Slices, Heat Mass Transf., 52: 2271-2281 (2016).
[54] Aghbashlo, M., Kianmehr, M., Arabhosseini, A. (2008). Energy and Exergy Analyses of Thin-Layer Drying of Potato Slices in a Semi-Industrial Continuous Band Dryer, Drying Technol., 26: 1501–1508 (2008).
[55] Zeki B., Physical Properties of Food Materials. In: “Food Process Engineering and Technology”,  1-26. Elsevier Publishers, USA (2009).
[56] Minaei S., Chenarbon H. A., Motevali A., Hosseini A.A., Energy Consumption, Thermal Utilization Efficiency and Hypericin Content in Drying Leaves of St John’s Wort (Hypericum Perforatum), J. Energy in Southern Africa, 25(3): 27-35 (2014).
[57] Chen C., Venkitasamy C., Zhang W., Deng L., Meng X., Pan Z., Effect of Step-Down Temperature Drying on Energy Consumption and Product Quality of Walnuts, J. Food Eng.,285: 110105 (2020)
[59] Ozgen F., Celik N., Evaluation of Design Parameters on Drying of Kiwi Fruit, Appl. Sci., 9(10): 1-13 (2019).
[61] Mujaffar S., John S., Thin-Layer Drying Behavior of West Indian Lemongrass (Cymbopogan Citratus) Leaves, Food Sci. Nutri., 6: 1085-1099 (2018).
[62] Ju H-Y., Zhao S-H., Mujumdar A. S., Zhao H-Y., Duan X., Zheng Z-A., Gao Z-J., Xiao H-W., Step-Down Relative Humidity Convective Air Drying Strategy to Enhance Drying Kinetics, Efficiency, and Quality of American Ginseng Root (Panax quinquefolium), Drying Technol., 38(7): 903-916 (2020).
[63] Nwakuba N.R., Chukwuezie O. C., Osuchukwu L. C., Modeling of Drying Process and Energy Consumption of Onion (Ex-gidankwano Spp.) Slices in a Hybrid Crop Dryer, Amer. J. Eng. Res., 6(1): 44-55 (2017).
[64] Azadbakht M., Torshizi M., Ziaratban A., Aghili H., Energy and Exergy Analyses during Eggplant Drying in a Fluidized Bed Dryer, Agric. Eng. Int.: CIGR J., 19(3): 177-182 (2017).
[65] Motevali A., Minaei S., Banakar A., Ghobadian B., Khoshtaghaza M.H., Comparison of Energy Parameters in Various Dryers, Energy Convers. Manage., 87: 711-725 (2014).
[66] Motevali A., Minaei S., Banakar A., Ghobadian B., Darvishi H., Energy Analyses and Drying Kinetics of Chamomile Leaves in Microwave-Convective Dryer, J. Saudi Soc. Agric. Sci., 15: 179-187 (2016).
[67] Icier F., Colak N., Erbay Z., Kuzgunkaya E. H., Hepbasli A.A., Comparative Study on Exergetic Performance Assessment for Drying of Broccoli Florets in Three Different Drying Systems, Drying Technol., 28: 193-204 (2010).