Corn Starch‐Chitosan Proportion Affects Biodegradable Film Performance for Food Packaging Purposes

Abstract

This work proposes an advance towards the scaling of biodegradable filmsbased on corn starch and chitosan, considering the relevant film propertiesthat condition their use for food packaging and their economic feasibility. Theinfluence of corn starch: chitosan (CS:CH) proportion and chitosan molecularweight used in the formulation is also studied. Chitosan (CH) additionimproves film forming dispersions (FFDs) stability stored under refrigeratedconditions and enhances the film UV barrier properties and elongation atbreak, however material costs are higher. Films with higher starch contentexhibited higher elastic modulus and tensile strength. Water vapor barrier,heat-sealing capacity, and sealing resistance also increase with the corn starch(CS) proportion in film formulation. Taking into consideration the chitosantype used, the polymer-plasticiser and polymer-solvent interactions prevailand led to the development of more flexible materials in film formulationswith low molecular weight chitosan (LMW-CH). Meanwhile, polymer-polymerinteractions also became relevant in those obtained with MMW-CH leading toresistant films. The obtained results indicate that composite films could beused in food packaging design, with those formulated with 75% CS and 25%medium molecular weight chitosan (MMW-CH) being a good optionconsidering both the film?s properties as well as its economical feasibility.