Effects of emulsifiers on the properties of high- amylose corn starch/hydroxypropylmethylcellulose films

The edible films based on high-amylose corn starch( HACS) and hydroxypropylmethylcellulose( HPMC)were prepared for food packaging. In order to solve the problem of phase separation in the process of making films,the effects of types( monostearin,tween 80,sodium dodecyl sulfate) and adding amount( 1%,2%,3%) of emulsifiers on the properties of HACS/HPMC films were studied by determining mechanical properties,water solubility,crystallization properties and surface morphology. X-ray diffraction( XRD) analysis showed that the properties of HACS/HPMC films were affected by the V-type crystal structures formed between amylose and emulsifiers.FT-IR analysis showed that addition of emulsifiers to the composite films enhanced the hydrogen bonding interaction between HACS and HPMC. The total performance of the composite film with 2% monostearin was the best,the tensile strength and elongation at break were increased to 10.24 MPa and 15.86%,respectively.The cross section and surface of the film were smooth.This study proved that the compatibility of HACS and HPMC in the film forming process was improved by adding 2% monostearate and the composite film with excellent performance was obtained.