Abstract:
This research studied on the preparation of oxygen indicator films based on chitosan and β-cyclodextrin grafted chitosan with montmorillonite as a dispersant and a moisture absorber, methylene blue as an indicator, and glucose as a reducing agent by solution casting method. The increase in glucose content decreased the water solubility of films due to crosslinking via Maillard reaction, but increased the yellow shades of activated film resulting in the difference in color recovery of the films when exposed to oxygen. The addition of montmorillonite and the grafting of β-cyclodextrin onto chitosan strengthened the color changes of the films. Among the color measurement of all films, CDG1M film showed the most noticeable color change, especially at 75% RH. In addition, the color recovery of the films could be delayed by covering them with PET sheet. The activated films showed good storage stability at low temperature. The results suggested that these films could be potentially used as oxygen indicator for modified atmosphere packaging (MAP) of food products requiring low temperature storage, such as cured meat and ready meal products.