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To develop an activebiopolymerfilm based on chitosan, sodium caseinate, and rosemary essential oil (REO), the objective of this work was to investigate the effect of REO on the structure and physical properties of biopolymer films.Fourier transform infrared spectroscopywas conducted for fingerprinting to identify the REO addition. The thermal behaviour of each film was investigated using athermogravimetric analysis. Furthermore, the optical properties, surfacehydrophobicity, solubility, mechanical properties, and water vapour permeability were investigated. The results showed that the presence of REO changes the structural organisation of the blended sodium caseinate and chitosan film, thereby inducing an increase in the surface hydrophilicity of the film. However, the solubility and water vapour permeability of the film were not affected by the structural modification induced by REO. Moreover, a mild effect of the REO on the mechanical properties of the sodium caseinate/chitosan film was observed. A thermal analysis confirmed that the incorporation of REO did not influence the degradation temperature of the films. Overall this studying has demonstrated that caseinate/chitosan film enriched in REO, related to his thermal and chemico physical properties can be applied for food packaging application.

The effect of caseinate/chitosan blend on the shelf life of minimally processed apples was studied. In the first phase of the work, the effect of the biopolymer coating on the respiration rate of the minimally processed apples was studied as function of gas composition (5%, 10%, 21% of O2 with N2 as balance at 5 &deg, C) and temperature (5 &deg, C, 10 &deg, C at 5% of O2 with N2 as balance). In the second phase, the shelf life of the packed product was studied during storage at 5 &deg, C. The gas composition (O2%-CO2%) in the package headspace, relative humidity, pH, hardness, color and antioxidant capacity of the product were monitored after 0, 1, 4, 7, 11, and 14 days. The coating effectively reduced respiration rate of the product when oxygen was over 10%. In the presence of the coating, the reduction of oxygen did not affect the respiration rate. At 5% of O2, the respiration rate decreased by 50% by changing the temperature from 10 &deg, C to 5 &deg, C. Shelf life study showed that the chitosan&mdash, caseinate coating was able to preserve the mechanical properties and the antioxidant capacity of the product during storage by increasing the shelf life by 7 days to 11 days at 5 &deg, C.