Journal of Food Engineering, Vol.104, No.1, 89-95, 2011
Microencapsulation of bayberry polyphenols by ethyl cellulose: Preparation and characterization
The polyphenolic extracts from bayberry were micro-encapsulated by a phase separation method using ethyl cellulose as a coating material. The microcapsules obtained were further characterized on polyphenols content, antioxidant capacity, particle size distribution, microstructures, in vitro study and storage stability. Results of antioxidant capacity assays showed that the antioxidant activity of bayberry polyphenols could be effectively protected by microencapsulation. The microcapsules were found to have a smooth surface shape with a particle size distribution of 10-97 mu m by light microscope and SEM observation. Release rate of bayberry polyphenol from microcapsules was within the range of 2.56-15.14% under simulated gastric fluid with pH of 2-6. Comparatively, release rate of bayberry polyphenols increased significantly (up to 87.37%) under simulated intestinal fluid 24 with pH of 8. The storage stability of bayberry polyphenols against adverse environment was also remarkably improved by microencapsulation. This study would contribute to the guide of application of bayberry polyphenols on food processing. (C) 2010 Elsevier Ltd. All rights reserved.