Microstructure and permeability of hollow microcapsules produced from faba bean 11s protein

Abstract Faba bean (FB) 11s protein was found to form hollow microcapsules (HMs) upon heating. The microstructure of HMs were characterized by microscopes; the HMs can have multiple vacuoles and the HM wall was composed of a layer of compact protein particles. At pH 4.0–5.0, below the isoelectronic point of the 11s protein, the HMs were able to encapsulate high amount of FITC-dextran and the driving force was the surface charge difference. As the pH was modified to 6.9, the HMs pre-treated with pH 4.0 and 5.0 exhibited pH-responsive release of FITC-dextran, while those pre-treated with pH 4.5 retained FITC-dextran within the HMs. However, the HMs did not show ionic strength-responsive permeability. Additionally, addition of HMs into semi-solid gelatine-agar samples significantly (p