Optimization of Vegetal Pear Drying Using Response Surface Methodology

The aim of this work was to optimize the drying process of vegetal pear and minimize energy resources (cost) under prefixed limits involving vegetal pear moisture, color, and productivity. The optimization of vegetal pear drying was made by using response surface methodology (RSM) for minimum process cost and color difference between fresh and dried samples (moisture <= 0.10 g water g d.m.(-1)). A pilot-plant dryer was used for dehydrating vegetal pear slices (0.5 cm thickness). The tests were carried out at different air temperature (60 to 70 degrees C), samples diameter (4 to 7 cm), and pretreatment with ascorbic acid solutions (0-0.1% w/w). The optimum drying conditions were found at air temperature of 63 degrees C with 5-cm sample diameter and 0.075% of ascorbic acid concentration. On the optimized drying conditions, dried vegetal pear presented values with moisture content of 0.052 g water g d.m.(-1), color difference of 11.65, production rate of 0.0073kg h(-1), and total cost of $30.58/kg dried product(-1)