Characterization of xyloglucan-based films incorporated with oregano essential oil (Origanum vulgare)

Edible films and coatings are protective layers applied to foods to improve their stability during storage. They are typically based on edible biomacromolecules, such as polysaccharides or proteins, which serve as a matrix, binder, or binding agent, and are combined with plasticizers like polyols to form a continuous and cohesive layer. Additional components with antimicrobial or bioactive properties may be included. In this study, films were developed using xyloglucan extracted from jatobá seeds, incorporating oregano essential oil (OEO). The films were prepared by mixing water, xyloglucan, and glycerol, homogenized at 40°C for 1 hour. OEO was added at concentrations of 0% (F0), 2% (F2), 3.5% (F3), and 5% (F5). The mixtures were poured into 15 cm² polyethylene containers and dried at room temperature for 3 days. The films were characterized by pH, thickness, water activity (Aw), opacity (Abs 600/mm) with means compared using Tukey’s test (95% confidence). The pH remained stable between 6.88 and 6.93, with no significant differences across samples, indicating OEO concentration did not affect this parameter. Thickness slightly increased with OEO addition, from 0.06 mm in F0 to 0.09 mm in F5, but there were no statistical differences between the OEO-containing samples. All samples showed an Aw of 0.36, likely due to the drying process. The opacity of F0 was 14.739, significantly higher than that of F2, F3, and F5, which had values of 9.247, 6.924, and 8.956, respectively, indicating that OEO reduced opacity. Aside from reducing opacity, which is a beneficial trait as it prevents interference with the visual appearance of foods, OEO did not significantly affect the other properties. This indicates that the formulation using xyloglucan as the polymer matrix was robust, and the incorporation of OEO may also have the potential to provide bioactive and antimicrobial properties, extending the shelf life of food products.