The Effect of Spray-Drying Conditions on the Characteristics of Powdered Pistacia lentiscus Leaf Extract

Pistacia lentiscus is an evergreen shrub widely used in folk medicine due to the high biological potential of the leaves' phenolic compounds. Since phenolic compounds are susceptible to degradation under different heat, light and oxygen conditions, various microencapsulation techniques, such as spray drying, can be used to increase their stability. The objective of this study was to examine the influence of different carriers (gum arabic (GA), maltodextrin 13-17 DE (MD), beta-cyclodextrin (BCD) and their mixtures), carrier concentrations in feed (12.8, 16 and 19.2% (m/V)) and drying temperatures (120, 150 and 180 degrees C) on the physiochemical properties, total phenolic content (TPC) and antioxidant activity (AOA) of Pistacia lentiscus leaf extract powders. Product yields of powders ranged from 23.53 to 65.51%, moisture content from 2.89 to 12.03%, hygroscopicity up to 4.45 g/100 g, solubility from 27.11 to 86.84% and bulk density from 0.24 to 0.45 g/mL. All obtained powders had satisfactory physicochemical properties, except BCD powders, which resulted in the lowest product yield, solubility and bulk density. However, BCD powders and those produced with GA containing mixtures retained the highest amounts of TPC and AOA. Thereby, the carrier mixtures with GA at a concentration of 19.2% and dried at 150 degrees C are recommended as the most suitable for the production of encapsulated Pistacia lentiscus leaf extracts with desirable physicochemical properties, rich in phenolics and with high antioxidant activity.