Development and properties of new kojic acid and chitosan composite biodegradable films for active packaging materials.

Chitosan and kojic acid composite films (CHn-KAm) utilizing three chitosan with differing molecular weights and kojic acid in different ratios were investigated. Results showed that chitosan with higher molecular weights presented higher viscosity, mechanical properties and lower water vapor permeability. Furthermore, kojic acid addition further significantly decreased apparent viscosity, water content, water vapor permeability as well as increasing the antibacterial activity of the films. Increasing the kojic acid concentration resulted in increased levels of a*, b*, ΔE*, opacity values and a decreased L* value, as compared to chitosan films. The mechanical properties of CHn-KAm films increased significantly with kojic acid addition into chitosan. FTIR spectral analyses revealed a strong interaction in the film matrix consistent with composite film mechanical and physical properties. The CHn-KAm films showed significant antibacterial effectiveness. The results suggested that the use of chitosan with a higher molecular weight as CHn-KAm films is expected to be a promising material for food packaging.