Structural characterization and properties of konjac glucomannan and zein blend films.

A series of konjac glucomannan (KGM)/zein blend films were successfully prepared with zein in proportions 0-30%. The hydrophobicity of blend films were significantly stronger than pure KGM film, indicated by increased contact angle, swelling and solubility properties, and moisture absorption. Moreover, other properties including mechanical, thermal, water vapor and oxygen barrier were also found to be increased. FTIR indicated that hydrogen bond interactions and Maillard reaction occurred between KGM and zein molecules, and microstructural observations indicated that the aggregated zein was homogeneously dispersed in the KGM continuous matrix. However, these zein aggregations were larger with increased proportion of zein, leading to weakened molecular interactions with zein proportion >10%. A mixing ratio of KGM:zein=9:1 was suggested to provide best film properties. This research offers an alternative improvement for KGM-based biodegradable films.