Functional properties and characterization of maize starch films blended with chitosan

The preparation of biodegradable composite films from blending chitosan in maize starch via solution casting was explored and the effect of the ratio of chitosan/starch on the physicochemical, mechanical properties and antimicrobial activity of the films was investigated. The interaction through hydrogen bonding between starch molecules and chitosan and the reduction of crystallinity in blend films were revealed in FTIR and XRD results. The blend films with incorporation of proper amounts of chitosan to a maize starch matrix displayed an enhancement in tensile properties and water vapor barrier performance, an improvement in rigidity and antimicrobial activity accompanied by higher transparency. The film with 1/3 of chitosan/starch ratio appeared homogeneous structure, 21.54 +/- 0.78 MPa of tensile strength and (2.81 +/- 0.26)x10(-10) g center dot m(-1)center dot s(-1)center dot Pa-1 of water vapor permeability which were 1.52 times higher and 60.9% lower than those of starch film, respectively. The deteriorated comprehensive performance of the films could be caused by excessively high chitosan content because of an incomplete miscibility between starch and chitosan. The chitosan/starch blend film possessed reasonable thermal stability and it could potentially be useful for food packaging applications.