Rheological Studies of Chitosan-Essential Oil Emulsions for Food Packaging Applications

Chitosan solutions of varying concentrations were prepared by dissolving in 1% acetic acid. Emulsions of these solutions were also prepared by addition of 2% clove essential oil and cinnamon essential oil. Attempt was made to understand rheological behaviour of these solutions through study of stress and viscosity behaviour with change in shear rate. All solutions were found to have a yield stress value. The rheological data was modelled and the solutions were found to have fluid characteristics between pseudo-plastic and Bingham plastic behaviours. The flow index (n)and consistency index (K) were compared for Herschel-Bulkley, Bingham and Oswald models. It was observed that only the chitosan content significantly affected the model parameters. Though changes in n and K values were observed on addition of essential oils, there were not statistically significant (P<0.05)