Characterization of a novel konjac glucomannan film incorporated with Pickering emulsions: Effect of the emulsion particle sizes

In order to understand the effects of emulsion particle sizes on the properties of novel konjac glucomannan (KGM)-based emulsion films, four types of Pickering emulsions with different oil phase (10%, 30%, 50% and 70%, v/v) were prepared by the same stabilizers (2% BCNs/SPI colloidal particles dispersions) and added into the film-forming solutions to keep the same final oil content (0.2%, w/v) in all KGM-based emulsion films. The results showed that the average particle sizes of the prepared Pickering emulsion increased with the increase of the oil phase in emulsion system. The microstructure analyses indicated that the KGM-based emulsion films became smoother as the emulsion particle sizes increased. Moreover, the contact angle values of KGM-based emulsion films slightly increased with the increase of the emulsion particle sizes, while the thermal stability of KGM-based films was not significantly affected by the particle sizes. Furthermore, the KGM-based emulsion films formed mainly through the hydrogen bond interactions as analyzed by FTIR. In addition, with the increase of the emulsion particle sizes, physical and mechanical properties of KGM-based emulsion films were significantly affected. Taken together, these results suggested that the particle sizes of Pickering emulsions had remarkable effects on the properties of KGM-based emulsion films.