Authors: Elham Azarpazhooh Hosahalli S Ramaswamy
Publish Date: 2011/01/14
Volume: 5, Issue: 5, Pages: 1486-1501
Abstract
The objective of this study was to model and optimize the mass transfer behavior during microwave osmotic dehydration of apple cylinders under continuousflow spray mode processing conditions Data needed for the model development and optimization were obtained using a central composite rotatable experimental design involving sucrose concentration 333–668°B temperature 333–668 °C flow rate 2120–3480 ml/min and contact times 5–55 min and the response variables were moisture loss solids gain and weight loss Mass transfer kinetics was evaluated based on the empirical Azuara model and the conventional diffusion model Diffusivities of both moisture loss D m and solids gain D s obtained from the diffusion model were related to sucrose concentration temperature and flow rate Optimization was evaluated using a desirability function model which could be used with several imposed constraints The optimum conditions obtained depended on the imposed constraints A set of constraints involving maximizing moisture loss and weight reduction while keeping the solids gain below 35 gave the following optimal conditions a 30min osmotic treatment at 65°B 60 °C and 2800 ml/min flow rate yielding a moisture loss of 409 weight reduction of 377 with a solids gain of 332
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