# Rosehip Seed Oil-Incorporated Chitosan Films for Potential Fruit Packaging Applications
## 4 Conclusions  
The physicochemical, antioxidant, and antifungal properties of casted chitosan films, containing different amount of rosehip seed oil emulsion (1%, 2%, 3%, 4%, and 5%) were investigated in the present research. The loaded RSO decreased the films strength and improved their mechanical properties by increasing their elasticity. The total color difference was slight for a RSO emulsion concentration under 3%, and sharply increased at higher concentrations. The addition of oil led to a reduction in water content. However, water vapor permeability and surface free energy increased due to the presence of inhomogeneity and micro-sized oil droplets. With respect to improving the hydrophobicity of the films, an optimization of the composition and method of formulation are necessary. Based on the thermal analysis, the incorporation of RSO does not affect the film stability up to 100 \({}^{\circ}\)C and therefore, the films are suitable for the food packaging of fresh or minimally processed food. At the same time, RSO significantly improves antioxidant activity. Based on the obtained results, it can be concluded that all of the measured parameters of the films remain stable up to a 3% concentration of the oil emulsion, after which they change significantly. For these reasons, this concentration can be used as optimal for the creation of edible coatings to prolong fruit shelf life. In addition, the evaluation of the antifungal activity of the new films showed that their surface did not retain fungal cells or their spores and provided an opportunity to maintain a sterile area of the coatings. Our future plans include the  
Figure 7: Surface resistance of chitosan/RSO edible film samples to fungi: (**a**) film with 0% RSO emulsion; (**b**) film with 2% RSO emulsion; and (**c**) film with 3% RSO emulsion, on which _S. cerevisiae_ was cultivated for 72 h.  
application of the chitosan/RSO coatings on concrete foodstuff and the investigation of the effect of the packaging on food safety and quality parameters (physical, physicochemical, and sensory). In this way, the best optimization of the composition and formulation method could be achieved.  
Conceptualization, M.M. and G.Z.; methodology, M.M., A.V., G.Z. and S.R.-V.; software, G.Z. and A.V.; validation, M.M., G.Z., and S.R.-V.; formal analysis, A.V.; investigation, M.M., A.V., G.Z., B.G. and S.R.-V.; resources, M.M., G.Z. and S.R.-V.; data curation, G.Z.; writing--original draft preparation, M.M., A.V., G.Z. and S.R.-V.; writing--review and editing, M.M. and A.V.; visualization, G.Z.; supervision, M.M.; project administration, G.Z.; funding acquisition, G.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Bulgarian Science Fund (BSF), grant number KP-06-N-37/29.  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the corresponding author on request.  
The authors thank the Agricultural Academy of Bulgaria, project No TN 14, for providing access to the scientific infrastructure and sophisticated equipment for this work.  
The authors declare no conflicts of interest.