Maltodextrin Moderated Microwave Osmotic Dehydration of Mango Cubes with Finish Air-Drying: Optimum Considerations

The microwave osmotic dehydration of mango cubes under the continuous flow of maltodextrin moderated sucrose solution spray (MWODS) was evaluated based on the quality of the finish air-dried product. Experiments were designed according to a central composite rotatable design to evaluate the effect of maltodextrin moderated sucrose solution [sucrose + maltodextrin (10DE) at a proportion of 85:15] on the finish air-dried product. The process variables were temperature (30 to 70 degrees C), solute concentration (30 to 70%), contact time (10 to 50 min) and flow rate (0.8 to 3.8 L/min). The optimum processing conditions were determined based on several processes and product-related quality parameters such as moisture loss (ML), solids gain (SG), weight gain, ML/SG, color, texture, rehydration capacity (RHC), bulk density and drying time. The MWODS contact time was the largest significant contributor with respect to most of the parameters, followed by temperature. The optimum values found were an osmotic treatment temperature of 51.7 degrees C, a solute concentration of 58.5%, a contact time of 30.6 min and a solution flow rate of 1.8 L/min. Finally, these optimized processing conditions were used to compare three different solute mixtures [sucrose only, sucrose + dextrose and sucrose + maltodextrin (10DE) at a ratio of 85:15%] to understand the effect of various solutes on the quality of the finished dried product. Based on the color and textural parameters, along with the RHC, of the finished product, the sucrose + maltodextrin mixture was shown to result in the most desirable quality and the air-dried product without MWODS pretreatment (control) resulted in the least desirable. Overall, the results suggest that the sucrose + maltodextrin combination offered an advantage in terms of quality for the MWODS air-drying of mango cubes.