The study of physicochemical and antioxidant properties of encapsulated Portulaca oleracea aqueous extract prepared by spray drying method

Portulaca oleracea is a rich source of antioxidants and is known as a plant with high nutritional value containing bioactive compounds. The encapsulation is one of the most common ways to increase the stability of bioactive compounds and protect them from environmental conditions to increase bioavailability. In this study, the production of encapsulated powder of Portulaca oleracea aqueous extract with different maltodextrin concentrations was investigated by spray drying method. The results showed that the highest production efficiency (59.67%) was related to the sample with the highest carrier concentration. Samples containing higher maltodextrin concentration had higher solubility and the solubility of encapsulated powder increased from 93.54 for MD5 sample to 98.86% for MD15 sample. Increasing the carrier concentration from 5 to 15 % reduced moisture content (from 2.08 to 1.32%), water activity (from 0.145 to 0.101) and density (from 0.49 to 0.39 g.ml-1). By increasing the carrier concentration from 5 to 15%, the total phenol content and antioxidant activity of encapsulated powder increased from 146.54 to 188.34 mgGAE/100g, and from 68.74 to 82.53%, respectively. The results of this study showed that the use of maltodextrin carrier in spray drying method can be effective to increase the stability of Portulaca oleracea aqueous extract and increase the stability of this extract against environmental conditions.