Preparation and properties of rice starch-chitosan blend biodegradable film

Biodegradable blend films from rice starch-chitosan were developed by casting film-solution on leveled trays. The influence of the ratio of starch and chitosan (2:1, 1.5:1, 1:1, and 0.5:1) on the mechanical properties, water barrier properties, and miscibility of biodegradable blend films was investigated. The biodegradable blend film from rice starch-chitosan showed an increase in tensile strength (TS), water vapor permeability (WVP), lighter color and yellowness and a decreasing elongation at the break (E), and film solubility (FS) after incorporation of chitosan. The introduction of chitosan increased the crystalline peak structure of starch film; however, too high chitosan concentration yielded phase separation between starch and chitosan. The amino group band of the chitosan molecule in the FTIR spectrum shifted from 1541.15 cm(-1) in the chitosan film to 1621.96 cm(-1) in the biodegradable blend films. These results pointed out that there was a molecular miscibility between these two components. The properties of rice starch-chitosan biodegradable blend film and selected biopolymer and synthetic polymer films were compared; the results demonstrated that rice starch-chitosan biodegradable blend film had mechanical properties similar to the other chitosan films. However, the water vapor permeability of rice starch-chitosan biodegradable blend film was characterized by relatively lower water vapor permeability than chitosan films but higher than polyolefin. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.