Properties and Stability of Encapsulated Pomegranate Peel Extract Prepared by Co-Crystallization

Abstract

Recently, there has been much interest in the phenolics of pomegranate peels because of their health-promoting effects. The incorporation of encapsulated phenolic extracts in functional foods, beverages, and dietary supplements can enhance their nutritional and health benefits. This paper aims to provide an overview of the encapsulation of pomegranate peel phenolic extract by co-crystallization, focusing on the properties of the encapsulated extract. Pomegranate peel extract encapsulated in sucrose by co-crystallization under conditions determined in our previous work is characterized by evaluating its properties—moisture content, solubility, bulk density, hygroscopicity, color, degree of encapsulation (using thermograms), crystallinity (using X-ray scattering), microstructure (with scanning electron microscopy), and storage stability in terms of total phenolic content and antioxidant activity. The co-crystallized powder had a low moisture content (0.59%) and hygroscopicity (0.011%) and a high bulk density (0.803 g/cm3) and solubility (61 s). Its total phenolic content decreased by only 0.56% after storage at 60 °C for 45 days, whereas its antioxidant activity was maintained at levels higher than 84%. The differential scanning calorimetry and X-ray scattering techniques proved the successful encapsulation in the sucrose matrix and the fact that the extract remained liquid inside the porosity of the sucrose crystals.