Characterization of Okra Convective Drying, Influence of Maturity

Ouoba Kondia Honoré, Zougmoré François, Sam Raguilignaba, Toguyeni Aboubacar, Desmorieux Hélène

Institut de Développement Rural, Université Polytechnique de Bobo, Bobo-Dioulasso, Burkina Faso.
Laboratoire d’Automatisme et de Génie des Procédés (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bat.308G, 43 bd du 11 Nov. 1918 Villeurbanne, Université Claude Bernard Lyon 1, 69622, Lyon, France.
Laboratoire des Matériaux et Environnement (LAME), Unité de Formation et de Recherche en Sciences Exactes et Appliquée (UFR/SEA), Université de Ouagadougou, Ouagadougou, Burkina Faso.
Laboratoire des Matériaux et Environnement (LAME), Unité de Formation et de Recherche en Sciences Exactes et Appliquée (UFR/SEA), Université de Ouagadougou, Ouagadougou, Burkina Faso ；Laboratoire d’Automatisme et de Génie des Procédés (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bat.308G, 43 bd du 11 Nov. 1918 Villeurbanne, Université Claude Bernard Lyon 1, 69622, Lyon, France.

DOI: 10.4236/fns.2014.56069                

Abstract

An experimental study for the drying kinetics of whole okra was carried out. In the study, different ages were considered by taking into account influence of okra maturity on its convective drying. The 2D moisture evolution inside the product and its maturity were evaluated by fitting experimental data versus drying time. The water effective diffusion coefficient of okra at different maturity states was gotten by the experimental model using Fick’s second law. A parametric study was carried out in the ranging of okra age from 2 to 7 days at 60℃, both fruits gathered on the same plant to avoid divergences due to okra varieties that can induce difference on physical structure and the chemical composition. It was found from the experimental results that okra maturity has important influence on its behaviour during convective drying. At 2, 3, 4, 5 and 7 days old, the drying effective time was respectively 780, 1000, 1155, 850 and 750 min. Effective diffusivity of the okra in this order of age was 1.38 × 10^-10, 6.09 × 10^-11, 1.23 × 10^-11, 8.98 × 10^-11, and 1.05 × 10^-10 m²/s in the present study, while the average initial moisture content was respectively 12.27, 9.00, 7.53, 5.97 and 4.92 Kgw/Kgdm.

Keywords

Convective Drying; Okra; Effective Diffusivity; Maturity; Initial Moisture Content

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Sankar, B., Abdul, J.C., Manivannan, P., Kishorekumar, A., Somasundaram, R. and Panneerselvam, R. (2008) Relative Efficacy of Water Use in Five Varieties of Abelmoschus esculentus (L.) Moench. under Water-Limited Conditions Colloids and Surfaces. Biointerfaces, 62, 125-129. http://dx.doi.org/10.1016/j.colsurfb.2007.09.025
[2]	Avallonea, S., Tiemtorea, T.W.E., Rivierb, C. and Trècheb, S. (2008) Nutritional Value of Six Multi-Ingredient Sauces from Burkina Faso. Journal of Food Composition and Analysis, 21, 553-558. http://dx.doi.org/10.1016/j.jfca.2008.04.012
[3]	Camciuc, M., Deplagne, M., Vilarem, G. and Gaset, A. (1998) Ocra (Abelmoschus esculentus L. Moench.) a Crop with Economic Potential for Set Aside Acreage in Frances Industrial. Crops and Products, 7, 257-264. http://dx.doi.org/10.1016/S0926-6690(97)00056-3
[4]	Sengkhamparn, N., Sagis, L.M.C., Renko de Vries, A., Henk Schols, H.A., Sajjaanantakul, T., Alphons, G.J. and Voragen, A.G.J. (2008) Physicochemical Properties of Pectins from Ocra Abelmoschus esculentus L. Moench. Food Hydrocolloids, 24, 35-41. http://dx.doi.org/10.1016/j.foodhyd.2009.07.007
[5]	Adelakun, O.E., Oyelade, O.J., Ade-Omowaye, B.I.O., Adeyemi, I.A. and Van de Venter, M. (2009) Chemical Composition and the Antioxidative Properties of Nigerian Ocra Seed (Abelmoschus esculentus Moench) Flour. Food and Chemical Toxicology, 47, 1123-1126. http://dx.doi.org/10.1016/j.fct.2009.01.036
[6]	Ouoba, K.H., Desmorieux, H., Zougmoré, F. and Naon, B. (2010) Caractérisation du Séchage Convectif du Gombo, Influence de la Découpe et de ses Constituants. Afrique SCIENCE, 10, 37-48. http://www.afriquescience.info
[7]	FAOSTAT (Food and Agricultural Organization of the United Nations) (2008) On-Line and Multilingual Database Currently Covering International Statistics. http://faostat.fao.org/site/339/default.aspx
[8]	Kordylas, J.M. (1991) Processing and Preservation of Tropical and Subtropical Foods. Macmillan Education Ltd.
[9]	Corzo, O., Bracho, N. and Alvarez, C. (2008) Water Effective Diffusion Coeffcient of Mango Slices at Different Maturity Stages during Air Drying. Journal of Food Engineering, 87, 479-484. http://dx.doi.org/10.1016/j.jfoodeng.2007.12.025
[10]	AOAC (Association of official Chemists) (1990) Official Methods of Analysis. Washington AC, 934-06.
[11]	Crank, J. (1975) The Mathematics of Diffusion. 2nd Edition, Oxford University Press, London, 69-88.
[12]	Nuh, D.N. and Brinkworth, B.J. (1997) A Novel Thin-Layer Model for Crop Drying. Transactions of the American Society of Agricultural Engineers, 40, 659-669.
[13]	Pala, M., Mahmutoglu, T. and Saygi, B. (1996) Effects of Pretreatments on Quality of Open-Air and Solar Dried Apricots. Nahrung/Food, 40, 137-141.
[14]	Riva, M. and Peri, C. (1986) Kinetics of Sun and Air Drying of Different Varieties of Seedless Grapes. Journal of Food Technology, 21, 199-208. http://dx.doi.org/10.1111/j.1365-2621.1986.tb00441.x
[15]	Rosello, C., Simal, S., SanJuan, N. and Mulet, A. (1997) Nonisotropic Mass Transfer Model for Green Bean Drying. Journal of Agriculture and Food Chemistry, 45, 337-342
[16]	Gogus, F. and Maskan, M. (1999) Water Adsorption and Drying Characteristics of Okra (Hibiscus Esculentus L.). Drying Technology, 17, 883-894. http://dx.doi.org/10.1080/07373939908917576
[17]	Gupta, P., Ahmed, J., Shivhare, U.S. and Raghavan, G.S.V. (2002) Drying Characteristics of Red Chilli. Drying Technology, 20, 1975-1987. http://dx.doi.org/10.1081/DRT-120015579
[18]	Madamba, P.S., Driscoll, R.H. and Buckle, K.A. (1996) The Thin-Layer Drying Characteristic of Garlic Slices. Journal of Food Engineering, 29, 75-97. http://dx.doi.org/10.1016/0260-8774(95)00062-3