Films based on Salvia hispanica and clove oil: physical, optical and mechanical properties

Clove essential oil (CEO) was added to Salvia hispanica mucilage–protein-rich fraction in an attempt to design a natural and biodegradable packaging film with good physical, optical and mechanical properties. The effects of polymer concentration (PC) (1.0–3.0%, w/v), CEO concentration (0.1–1.0%, v/v) and pH (7–10) were evaluated using a face-centered central composite design. The films corresponding to treatment with intermediate PC (2.0%, w/w), pH (8.5) and higher concentration of CEO (1.0%, w/w) exhibited a lower water content, were partially soluble and showed adequate thickness and density. With regard to optical characteristics, the films were bright and transparent and exhibited high values of the whiteness index. Under the same conditions, films with suitable mechanical properties were obtained. This formulation is tentatively suggested for application in food products.