The effect of ultrasound applications and different drying methods on some physiochemical properties of mango powder

In this study, mango slices pretreated by ultrasound (ULS) and dried by different drying methods were examined for some quality parameters and the drying kinetics of mango powder samples. Mango slices were pre-treated with ULS for two different periods (15 and 30 min) and then dried in nine different ways using hot air (SH), microwave (MD) and microwave-hot air (MDSH) combination methods. In general, in all drying trials, it was found that the application of ULS pretreatment resulted in a faster removal of moisture from the structure of the mango slices, and the longer the ULS pretreatment time applied, the lower the drying time. It was determined that mango samples pre-treated with ULS (30 min) and dried by MDSH method at 200W+70 ○C had a reduction of approximately 80% in drying time and that the drying rate was higher than samples dried under other conditions. A significant change was observed in the bulk, tapped and particle density values of mango powder samples obtained with different drying parameters (p<0.05). The porosity values of mango powders ranged from 53.11 to 64.27% (p<0.05), and the lowest porosity values were determined in powdered samples dried at 70 °C without ULS pretreatment. The flowability and cohesiveness values of samples subjected to ULS pretreatment (30 min) increased significantly compared to samples without pretreatment. A decrease in the total phenolic substance and antioxidant capacity values of mango powder samples were observed with increasing ULS administration time. The highest total phenolic substance and antioxidant capacity values were determined in the MD method, while the lowest total phenolic substance and antioxidant capacity values were determined in samples pre-treated with ULS for 30 min and dried by SH method. In general, it was determined that the L* and b* values of the color parameters of the samples decreased and the a* value increased with all drying applications. The lowest ∆E value was determined in samples that were pre-treated with ULS for 30 min and dried by MDSH application. When the SEM images of mango powder samples were examined, it was found that the samples that were not pre-treated and dried at a temperature of 70 °C had a more homogeneous structure and very small pores. When all the obtained data are evaluated as a whole, it is recommended that MD and SH drying techniques should be combined and supported by ULS pretreatment in order to obtain more efficient results from MD and/or SH drying methods.