Influence of fruit maturity on water diffusivity
during convective drying of mango
A. O. Dissa1*, H. Desmorieux2, F. Ouattara1, 3, P. Degraeve4, D. J. Bathiebo1, J. Koulidiati1
1 Laboratoire de Physique et de Chimie de l’Environnement (LPCE), Unité de Formation et de Recherche en Sciences Exactes et Appliquée (UFR/SEA), Université de Ouagadougou, 03 B.P 7021 Ouagadougou 03, Burkina Faso
2 Laboratoire d’Automatisme et de Génie des Procédés (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bât.308G, 43
bd du 11 Nov.1918 Villeurbanne, Université Claude Bernard Lyon1, Lyon, France
3 Université de Koudougou, BP 376, Koudougou, Burkina Faso
4 Laboratoire de Recherche en Génie Industrielle Alimentaire (LRGIA, Technopole Alimentec) EA 3733, IUT A (Université Claude Bernard Lyon 1), Rue Henri Boissieu, 01 060 Bourg en Bresse Cedex 09, France
Received: 02 March 2011; revised version accepted: 23 July 2011
Influence of fruit maturity on effective water diffusivity of mango was studied. The state of maturity was estimated by the index of maturity (Im) given by the ratio of total soluble solids (TSS) and titratable acidity (TAc) of fruit flesh. Three states of maturity (Im=126, 147 and 226) were used. Drying kinetics and drying rates curves were established for each state of maturity both in force and natural convection drying. Effective water diffusivities were deduced from these drying curves by considering two zone of diffusion. Diffusivities identified from these diffusion zones ranged from 1.66 x10-10 to 4.61 x10-10 m²/s for the 1st state of maturity, from 2.46 x10-10 to 8.01 x10-10 m²/s for the 2nd state of maturity and from 4.25 x10-10 to 1.28 x10-9 m²/s for the 3rd state of maturity (with R²>0.98). Thus, it was found that effective water diffusivity of mango significantly varied with the maturity state. Therefore, a suitable diffusivity law taking into account the index of maturity was established for mango fruit. Diffusivities calculated from this model were very close to experimental diffusivities with relative difference ranging from 0.48 to 12.82%.
Keywords: Mango; Maturity; Effective water diffusivity; Drying kinetics; Drying rate; Moisture content.