Effect of pre-treatment and different drying methods on the physicochemical properties of Carica papaya L. leaf powder

Abstract The Carica papaya L. leaves are often considered as wastes, but they are actually beneficial for health. The study was aimed to explore the effect of pre-treatment and different drying methods on the physicochemical properties of Carica papaya L. leaves powder. The leaves were blanched in hot water before they went through the drying process, which consisted of oven drying (OD), shade drying (SD) and freeze drying (FD). The results showed that blanching helped in improving the powder physical properties and preserving the phenolic compounds and ascorbic acid. Blanching also increaseed the bulk density and improved flowability in all drying methods, except for FD. Pretreated oven dried powder resulted in better physicochemical properties in other drying methods, except for vitamin C content, which was higher in freeze-dried powder. OD at 40 °C resulted in powder with the maximum bulk density (659 kg/m 3 ), excellent flowability, the least lightness and color change, the highest hue angle and maximum retention of total phenolic content (374 mg GAE/g).