Models for Predicting Moisture Diffusivity During Osmotic Dehydration of Two Cocoyam Varieties (Colocasia spp and Xanthosoma spp)
[1]
Olatidoye Olawale Paul, Department of Food Technology, School of Technology, Yaba College of Technology, Yaba, Lagos State, Nigeria.
[2]
Falade Kolawole O., Department of Food Technology, Faculty of Technology, University of Ibadan, Ibadan, Oyo State, Nigeria.
[3]
Akinoso Rahaman, Department of Food Technology, Faculty of Technology, University of Ibadan, Ibadan, Oyo State, Nigeria.
The influence of process variables on the kinetics of water loss during osmotic dehydration of Cocoyam varieties (Colocasia spp and Xanthosoma spp) slices in sugar solutions were investigated to provide information necessary for further drying and to enable processors maintain quality of cocoyam. Mass transfers during Osmotic dehydration of cocoyam slices in sucrose solutions were quantitatively investigated. Cocoyam tubers were cut into 20mm x 50mm x10mm, 20mm x50mm x15mm and 20mm x 50mm x 20mm, and were osmotically dehydrated in sucrose solution of 44°B, 52°B, 60°B and 68°B for 14 hr, maintained in water bath at 20°C, 30°C and 40°C. Data obtained were used to develop a model, validate and evaluate moisture diffusivity. Mean values recorded for moisture diffusivities were 17.31 x 10–9m2/s and 14.99 x 10–9m2/s for Colocasia and Xanthosoma spp respectively. However, no significance difference was recorded at 5% level of significance using t-Test and F-Test. Second order polynomial models for the two varieties of cocoyam produced good fit. High values of coefficients of determination R2 (0.986) and (0.981) were recorded for Colocasia and Xanthosoma spp respectively. This has shown that the models can be used to determine and predict degree of influence of sucrose solution concentration, slices thickness and temperature of solution on moisture movement in osmotic dehydration. Validation of the model gave errors of 3.91 and 4.25% for Colocasia and Xanthosoma spp respectively.
Cocoyam, Osmotic Dehydration, Moisture Diffusivity, Models, Solid gain, Water-Loss
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