Evaluation of the Dehydration Kinetics of Cassava (Manihot Esculenta) Slices Dried Using a Refractance WindowTM Dryer

  • A. A. Akinola Department of Chemical and Petroleum Engineering, University of Lagos, Lagos, Nigeria
  • S. N. Ezeorah
Keywords: Drying, Models, Rehydration Ratio, Regression Analysis

Abstract

The dehydration kinetics of cassava slices dried using a Refractance WindowTM, a novel contact surface drying technique, is presented in this study. The dryer was constructed by modifying a laboratory water bath. Cassava slices of 3 mm thick were dried on the Refractance WindowTM, and the moisture content of the slices was measured as the drying progressed. A water temperature between 75 80 oC was
maintained beneath the plastic film. Drying curves were obtained from the drying data, and the thin layer
model that best fit the drying data was determined. The bulk density and rehydration ratio of the dried
cassava were determined. The cassava slices were observed to dry to about 5 % moisture content after
210 minutes. The regression analysis results showed that the Haghi and Ghanadzadeh thin layer model
best described the drying data for 3 mm thick sized cassava slices. The Mean Bias Error (MBE), the
Coefficient of Determination (R2), the Root Mean Square Error (RMSE) and the Chi-square (?2) values
were -8.83x10-6, 9984.34x10-4, 4.20x10-4 and 4.41x10-4 respectively. The Rehydration Ratio increased to
a steady value of 3.17 in about 180 minutes.

References

Abdul-Fadl, M.M., and Ghanem, T.H. (2011). Effect of Refractance Window (RW)
Drying Method on Quality Criteria of Produced Tomato Powder as compared to
the Convection Drying Method, World Applied Sciences Journal 15(7), 953-965.
Adebowale, A.A., Sanni, L.O. and Onitilo, M.O. (2008). Chemical Composition and
Pasting Properties of Tapioca Grits from Different Cassava Varieties and
Roasting Methods, African Journal of Food Science, 2(7), 077-082.
Aghbashlo, M., Kianmehr, M. H., Khani, S, and Ghasemi, M. (2009). Mathematical
Modelling of Thin-Layer Drying of Carrot, Int. Agrophysics, 23(4), 313-317.
Ajao, K.R. and Adegun, I.K. (2009). Performance evaluation of a locally fabricated mini
cassava flash dryer. Researcher, 1(3), 54-60.
Akpinar, E.K. (2010). Drying of Mint Leaves in a Solar Dryer and Under Open Sun:
Modelling, Performance Analyses, Energy Conversion and Management, 51(12)
2407–2418, 2010. DOI: 10.1016/j.enconman.2010.05.005.
Ayankunbi, M., Keshinro, O. and Egele, P. (1991). Effects of Method of Preparation on
Nutrients Composition of Some Cassava Food Products: Gari (Eba), Lafun and
Fufu, Food Chemistry, 41(3), 349-354.
Ayensu, A. (1997). Dehydration of Food Crops Using a Solar Dryer With Convective
Heat Flow, Solar Energy, 59(4-6), 121 -126.
Baron Spices and Seasoning (2015). Dehydrated Onion and Garlic ProductsRehydration, Retrieved from
http://www.baronspices.com/spice_handbook/rehydration.html on 29-09-2015
Cock, J. H. (1982). Cassava: A Basic Energy Source in the Tropics Science, Science,
218 (4574) 755-762.
Cock, J. H. (1985). Cassava: New Potential for a Neglected Crop, Westview Press,
Boulder, CO, USA, 191 pages. (IADS Development-Oriented Literature Series).
Published
2019-03-11
How to Cite
Akinola, A. A., & Ezeorah, S. N. (2019). Evaluation of the Dehydration Kinetics of Cassava (Manihot Esculenta) Slices Dried Using a Refractance WindowTM Dryer. Journal of Engineering Research, 22(1), 1-10. Retrieved from http://jer.unilag.edu.ng/article/view/294