Formation of high amylose corn starch/konjac glucomannan composite film with improved mechanical and barrier properties

Recently, starch-based packaging materials have become one of research hot points. In the present study, glycerol-plasticized composite films based on high amylose corn starch (HCS) and konjac glucomannan (KGM) were developed. The influence of KGM on the film-forming properties of HCS and the physicochemical properties of the resulting films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and water vapor permeability (WVP). The crystallinity and the proportion of short-range order structure of the films increased first and then declined with the addition of KGM. The micromorphology of the films exhibited the more even texture after KGM was incorporated in. The tensile strength, elongation at break and water resistance of HCS film were also improved significantly. The synergistic effect between HCS and KGM improved the film-forming ability of HCS. The optimal addition amount of KGM was 0.3 %.

Automated summary

The addition of konjac glucomannan significantly improved the film-forming ability and physicochemical properties of high amylose corn starch film, with increased crystallinity and proportion of short-range order structure in the films before eventually declining. The micro morphology of the films became more uniform after the incorporation of konjac glucomannan.