Physical and chemical characteristics of encapsulated goldenberry (Physalis peruviana L.) juice powder

Goldenberry (Physalis peruviana L.) is an exotic fruit that is valued due to its high antioxidant activity and phenolic content. In order to preserve the bioactive contents, microencapsulation is a proper method to extend its shelf life. The aim of this study was to encapsulate goldenberry juice using maltodextrin mixed with gum arabic, alginate and pectin to enhance its stability at simulated digestion fluids. Different maltodextrin/gum arabic, alginate, pectin ratios (10:0, 9:1, 8:2) and core to coating ratios (3:10) were used and homogenized before freeze-drying for 48 h to obtain the microcapsules. The microcapsules were characterized through particle morphology, particle size distribution, phenolic contents, encapsulation efficiency, antioxidant activity, digestion behavior in the gastric-intestinal fluids, chromatographic and colorimetric analysis. The microcapsules prepared with maltodextrin and pectin had greater volume mean diameter (43.1 mu m) compared to those containing gum arabic and alginate. Goldenberry juice microcapsules, prepared by freeze-drying method, was shown to retain more than 75% phenolic compounds for all gum types. In vitro digestion studies showed that the release of phenolic compounds from microcapsules was higher in the simulated intestinal fluid than in gastric medium. (C) 2017 Elsevier Ltd. All rights reserved.