Properties of a new protein film from bitter vetch (Vicia ervilia) and effect of CaCl2 on its hydrophobicity

This work was aimed to investigate the potential preparation of an edible film from bitter vetch seed proteins. The film was cast from bitter vetch protein concentrate (BPC) and glycerol. CaCl2 at the ratio of 0.1–1% (w/w) of the BPC was tested to improve film properties, specially its hydrophobicity. Some physicochemical properties of the films obtained in the absence and presence of CaCl2 were evaluated. The results indicated that moisture content, total soluble matter, water vapour permeability and contact angle of the films prepared in the presence of CaCl2 were significantly modified in comparison with the control values, while their mechanical properties did not significantly change. The surface morphology of the films was also considerably affected by the presence of CaCl2. Therefore, CaCl2 could improve BPC-film barrier properties especially their hydrophobicity, even though calcium concentration seems to be a crucial factor.