Fabrication and characterization of the enhanced tensile strength xanthan/curdlan/gelatin blend films for food-packaging applications

Food packaging films are generally used to protect the food from outside harsh environment. Moreover, their main purpose is to prolong the shelf life and to maintain the freshness of food. Generally, plastic materials are widely used for this purpose. However, these plastic materials are causing a serious threats to our environment due to the problem of non-degradability. In this regard, biodegradable biopolymer materials are contemplated as an important alternative due to the environment friendly characteristics. However, the packaging films prepared from single pure polymers have been reported to possess very poor mechanical properties. Therefore, blending of two or three biopolymers is considered to synergistically improve the mechanical properties of biopolymer based films. In this work, we made a novel blended films of xanthan (X), curdlan (C) and gelatin (G) by mixing different ratios of all three polymers. After successfully preparing and optimization of these blended films, mechanical properties and moisture absorbance properties of all these films were determined. Based on the results, it was concluded that the highest tensile strength of 38.22 +/- 0.7 MPa was found in the T2 treatment of 20:20:60 ratio of X/C/G blend films. In addition, highest elongation at break of 18.92 +/- 0.5% was also found in the same rational of X/C/G blend films. Moreover, characterization techniques such as FT-IR and SEM analysis were also performed to analyze the structural properties of blend films. Finally, SEM micrographs indicated that all the blend films exhibited a uniform, smooth, homogenous and compact outer surface morphology. In short, this novel xanthan/curdlan/gelatin films resulted in improved mechanical properties of blend films, which confirm its suitability as promising food packaging material.