Mathematical Modeling of Sun and Solar Drying Kinetics of Fermented Cocoa Beans

Mathematical Modeling of Sun and Solar Drying Kinetics of Fermented Cocoa Beans ( Vol-2,Issue-5,September - October 2017 )

Author: Olabinjo O.O., Olajide J.O., Olalusi A .P.

ijeab doi crossref DOI: 10.22161/ijeab/2.5.19

Keyword: Thin-layer drying, moisture content, modelling,cut test, pH, Cocoa beans.

Abstract: In this study, thin layer drying experiments were conducted to compute drying characteristics of fermented cocoa beans in open sun and indirect natural convection solar dryer. The drying experiments were conducted at the same time for comparison. Three different thin layers drying of the fermented beans were examined under field conditions for Akure, Nigeria. The drying process took place only in the falling rate period. The drying curves obtained from the experimental data were fitted to thirteen (13) different thin layer mathematical models. All the models were compared according to three evaluation parameters. These include coefficient of determination (R2), Root mean square error (RMSE) and Chi-square (X2).The results showed that increasing drying air temperature resulted to shorter drying times. The Vermal et al. model was found to be the most suitable for describing the drying curve of the convective indirect solar drying process of cocoa beans with R2 = 0.9562, X2=0.0069 and RMSE=0.0067; while, the Midilli and Kucuk model, best described the drying curve of fermented cocoa beans under open sun with R2 = 0.9866, X2=0.0024 and RMSE=0.0023.


[1] Aghbasho M., M. H. Kianmehr and H. Samimi-Akhljahani (2008).Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin –layer drying of barberries fruit (Berberidaceae).Energy Conversion and Management,49(10):12865-2871
[2] Anon (1995).Specification for grading of Malaysian cocoa beans (3rd revision) SIRIM, Malaysia.
[3] Ayensu, A. (1997). Dehydration of food crops using a solar dryer with convective heat flow. Solar Energy 59:121-126.
[4] Babalis J.S, and Belessiotis G.V (2006). Influence of drying condition on the drying constants and moisture diffusivity during the thin layer drying of figs. Journal of Food Eng., 65: 449- 458
[5] Celma, A.R, S. Rojas, F. Lo´pez, I. Montero and T.Miranda, (2007). Thin-layer drying behavior of sludge of olive oil extraction. Journal of Food Engineering, 80: 1261-1271
[6] Ceylan, I., Aktas, M. and Dog˘an, H. (2007). Mathematical modeling of drying characteristics of tropical fruits. Applied Thermal Engineering 27: 1931-1936.
[7] Doymaz,I.(2005).Sundrying of figs: An experimental study. Journal of Food Engineering 71:403-407
[8] Doymaz,I. (2007). Air-drying characteristics of tomatoes. Journal of Food Engineering,78(4) 1291-1297.
[9] El-Beltagy, A., Gamea G. R., and Amer-Essa A. H. (2007).Solar drying character ristics of strawberry. Journal of Food Engineering 78: 456-464.
[10] ErenturkS.andErenturk. (2007).Drying of eggplant and selection of a suitable thin layer drying model.Journal of Food Engineering,63(3): 349-359.
[11] Ertekin, C., and Yaldiz, O., (2004). Drying of eggplant and selection of a suitable thin layer drying model. Journal of Food Engineering, 63, 349–359
[12] Faborede, M.O and Oladosu, F.A.,(1991). Development of cocoa pod processing machine. The Nigerian Engineer 26(4): 26-31.
[13] Goyal R. K., Kingsly, A. R. P., Manikantan, M. R. and Ilyas, S. M. (2007). Mathematical modelling of thin layer drying kinetics of plum in a tunnel dryer. Journal of Food Engineering 79: 176-180.
[14] Grow cocoa (2004). Global research on cocoa –working with and for farmers.
[15] Hii, C. L., Law, C. L., andCloke, M. (2009). Modeling using a new thin layer drying model and product quality of cocoa. Journal of Food Engineering, 90, 191 – 198.
[16] Kadlopa,A., and Ngwalo, G.,(2007).Solar dryer with thermal storage and biomass-back up heater. Solar Energy, 81(4):449-462.
[17] Kaleemullah S., and Kailappan R. (2006). Modelling of thin layer drying kinetics of red chillies. Journal of Food Engineering, 76(4): 531-537.
[18] Karathanos, V.T., (1999). Determination of water content of dried fruits by drying kinetics. Journal of Food Engineering, 39: 337-344.
[19] Kashaninejad, M., and Tabil, L. G. (2004). Drying characteristics of purslane (Portulacaoleraceae L.). Drying Technology, 22, 2183–2200.
[20] Kaya, A., Aydin, O., Demirtas, C. and Akgün, M. (2007). An experimental study on the drying kinetics of quince. Desalination 212: 328-343.
[21] Kingsly, A. R. P.and Singh D. B., (2007).Drying kinetics of pomegranate arils. Journal of Food Engineering, 79:741-744.
[22] Lagha-Benamrouche, S. and Madani, K., (2013). Phenolic contents and antioxidant activity of orange varieties (Citrus sinensisL. and Citrus aurantiumL. cultivated in Algeria: Peels and leaves. Industrial Crops and Products, 50: 723–730.
[23] Lahsasni, S., Kouhila, M., Mahrouz, M. and Jaouhari J. T. (2004b). Drying kinetics of prickly pear fruit (Opuntiaficusindica). Journal of Food Engineering 61: 173-179.
[24] Midilli, A. and Kucuk, H., (2003). Mathematical modeling of thin layer drying of pistachio by using solar energy. Energy Conversion and Management, 44(7):1111-1122.
[25] Midilli, A., H. Kucuk and Z. Yapar, (2002). A new model for single-layer drying. Drying Technology, 20: 1503-1513.
[26] Mustafa, I., Sopian, K. and Daud, W.R.W. (2009). Study of the Drying Kinetics of Lemon Grass. American Journal of Applied Sciences, 1071.
[27] Olalusi, A.P.,(2008). Design, construction and performance evaluation of an indirect solar dryer for shea nut.
[28] Opeke, L.K. (1982). Optimizing economic returns (profit) from cocoa cultivation through efficient use of cocoa by products. Proceeding of 9th International cocoa research conference Lome, Togo, February 12-18: 489-493.
[29] Ozdemir, M., and Devres, Y. O. (1999). The thin layer drying characteristics of hazelnuts during roasting. Journal of Food Engineering, 42, 225–233.
[30] Paulsen MR, Thomson TL. (1973). Drying endysus of grain sorghum. Trans ASAE 1973; 16:537–540.
[31] Prachayawarakorn, S., Tia, W., Plyto, N. and Soponronnarit, S. (2008). Drying kinetics and quality attributes of low-fat banana slices dried at high temperature. Journal of Food Engineering, 85:509-517.
[32] Rahman M.S, Perera C.O, Theband C. (1998) Desorption isoterm and heat pump drying kinetics of peas. Food Res Int 30:485–91.
[33] Sacilik, K., Keskin, R., and Elicin, A. K. (2006). Mathematical modeling of solar tunnel drying of thin layer organic tomato. Journal of Food Engineering, 73, 231–238.
[34] Saeed,I.E.,Sopian,K., and ZainolAbidin,Z.,(2006). Drying kinetics of Roselle (Hibiscus sabdariffa L.): dried in constant temperature and humidity chamber.Proc.SPS 2006.Edited by Muchtar. 29th -30thaugust.Permata,Bangi,S.D.E.,Malaysia :143-148.
[35] Saeed, I.E, K. Sopian and Z. ZainolAbidin, (2006). Drying kinetics of Roselle (Hibiscus sabdariffa L.): dried in constant temperature and humidity chamber. Proceeding, of SPS 2006. Ed Muchtaret al. 29-30 Aug. Permata, Bangi, Malaysia, 2006, pp: 143-148.
[36] Senadeera W., Bhandari, B. R., Young, G., and Wijesinghe, B. (2003). Influence of shapes of selected vegetable materials on drying kinetics during fluidized bed drying. Journal of Food Engineering, 58, 277–283.
[37] Sogi D. S., Shivhare U. S., Garg S. K., and Bawa, A. S. (2003). Water sorption isotherms and drying characteristics of tomato seeds. Biosystems Engineering, 84, 297–301.
[38] Sunseed Desert Technology (2003). Solar Drying: Drying Food with the energy of the Sun. Retrieved from
[39] Tarigan E., Prateepchaikul G., Yamsaengsung R., Sirichote A. and Tekasakul P., (2007). Drying characteristics of unshelled kernels of candle nuts. Journal of Food Engineering, 79: 828–833.
[40] Thomson T.L, Peart P.M, and Foster G.H (1968). Mathematical simulation of corn drying: A new model. Trans ASAE; 11:582–6.
[41] Togrul I. T. and Pehlivan D. (2003). Modeling of drying kinetics of single apricot. Journal of Food Engineering 58:23–32.
[42] Togrul I.T. and Pehlivan D. (2002). Mathematical modeling of solar drying of apricots in thin layer dryers. Journal of Food Engineering 55: 209-216.
[43] Togrul, I.T. and Pehlivan D., (2004). Modeling of thin layer drying kinetics of some fruits under open air sun drying process. Journal of Food Engineering, 65 (3): 413-425.
[44] Upadhyay A.H.K, Sharma, and Sarkar B.C., (2008). “Characterization and Dehydration Kinetics of Carrot Pomace”. Agricultural Engineering International: The CIGR Ejournal Manuscript.
[45] Wang C.Y., and Singh R.P., (1978). A single layer drying equation for rough rice. ASAE, paper no. 3001.
[46] Wang, Z, Sun J., Liao X., Chen F., Zhao G., Wu J. and Hu X., (2007). Mathematical modeling on hot air drying of thin layer apple pomace. Food Research International, 40: 39–46
[47] Yaldiz, O. and Ertekyn, C. (2001). Thin layer solar drying of some vegetables. Drying Technology 19(3-4): 583-597.

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