Effects of Drying Temperature on The Effective Coefficient of Moisture Diffusivity and Activation Energy in Ibadan-Local Tomato Variety (lycopersicum esculentum)

A study of the mechanism of mass transfer phenomena of Ibadan-local variety was carried out. Ibadan-Local tomato varieties pre-treated in a binary (sugar and salt) osmotic solution of concentration (45/15 o Brix), solution temperature (30, 40, 50 o C), was studied by developing a mathematical model to describe the Water Loss (WL) and Solid Gains (SG). Drying was monitored at three temperatures (40, 45 and 50 o C) until   equilibrium weight was achieved using the oven-dry method. Five thin layer drying models (Exponential, Henderson & Pabis, Page, Modified Page and Logarithmic) were compared and fitted into the experimental values of the non-linear moisture ratio; MR. The diffusion coefficient and activation energy were determined using the Arrhenius equation. Drying occurred in the falling rate phase and different models fit at different temperatures. Calculated values of effective moisture diffusivity varied from 1.17-3.51x10 -8 to 1.25-3.13x10 -8 and activation energy varied from a maximum of 52.61KJ/mol in treated to 46.81 KJ/mol in untreated tomato. At all temperatures, effective coefficient of moisture diffusivity and activation energy values was higher in osmosized tomato Keywords: Osmotic dehydration, Water loss, Solid gain, Effective moisture diffusivity and Activation energy .

[1]  İbrahim Doymaz,et al.  Drying kinetics of white mulberry , 2004 .

[2]  Aurelio López-Malo,et al.  IMPREGNATION AND OSMOTIC DEHYDRATION OF SOME FRUITS: EFFECT OF THE VACUUM PRESSURE AND SYRUP CONCENTRATION , 2003 .

[3]  O. Kolawole,et al.  Effect of sucrose and binary solution on osmotic dehydration of bell pepper (chilli) (Capsicum spp.) varieties. , 2010 .

[4]  G. E. Page,et al.  FACTORS INFLUENCING THE MAXIMUM RATES OF AIR DRYING SHELLED CORN IN THIN LAYERS. , 1949 .

[5]  Mortaza Aghbashlo,et al.  Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae) , 2008 .

[6]  Koksal Erenturk,et al.  Comparison of genetic algorithm and neural network approaches for the drying process of carrot , 2007 .

[7]  P. Cârlescu,et al.  Convective Air Drying Characteristics for Thin Layer Carrots , 2013 .

[8]  O. Strausz,et al.  Kinetics of the , 1967 .

[9]  F. Kaymak-Ertekin,et al.  Modelling of mass transfer during osmotic dehydration of apples , 2000 .

[10]  D. S. Khurdiya,et al.  Effect of microwave heating and conventional processing on the nutritional qualities of tomato juice , 1999 .

[11]  S. Alzamora,et al.  Structural changes in apple tissue during glucose and sucrose osmotic dehydration: shrinkage, porosity, density and microscopic features , 2004 .

[12]  C. Geankoplis.  Transport processes and unit operations , 1978 .

[13]  Y. Onur Devres,et al.  The thin layer drying characteristics of hazelnuts during roasting , 1999 .

[14]  D. Knorr,et al.  Kinetics of osmotic dehydration of red bell peppers as influenced by pulsed electric field pretreatment , 2003 .

[15]  Ebru Kavak Akpinar,et al.  Mathematical Modeling and Experimental Study on Thin Layer Drying of Strawberry , 2006 .