Multi-Objective Optimization of Osmotic–Ultrasonic Pretreatments and Hot-Air Drying of Quince Using Response Surface Methodology

In this study, application of a multi-objective optimization technique based on response surface methodology has been presented. Quince slices were dehydrated using osmotic dehydration with sucrose solutions at different concentration (40 and 60 Brix), processing time (1, 1.5, and 2 h), and ultrasonication time (0, 15, and 30 min) were the factors investigated with respect to water loss, solid gain, and weight reduction. Response surface methodology was used to determine the optimum processing conditions that yield maximum water loss and weight reduction and minimum solid gain during osmotic dehydration of quinces. Dehydrated quince slices at optimized osmo-ultrasound condition were then subjected to air-drying at 60 and 80 °C. Rehydration ratio, shrinkage, and moisture content of dried samples were regarded as responses to the non-thermal and air-drying conditions. Multi-objective optimization led to obtaining the best condition for production of dried quince slices with lowest moisture content, and shrinkage.