Collagen films, cassava starch and their blends: Physical-chemical, thermal and microstructure properties

Collagen-based films from Tilapia skin, cassava starch and their blends were prepared using the casting technique. Five treatments were prepared, where T1 represents the film containing 6% collagen, T2-film containing 6% cassava starch, T3-film containing 3%/3% blend of collagen/cassava starch, T4-film containing the 4.5%/1.5% blend of collagen/cassava starch and T5-film containing the blend of 1.5%/4.5% collagen/cassava starch. The physical, mechanical, thermal and morphological properties of each film were evaluated. The results indicated that T1 and T4 treatments improved film water resistance (p < 0.05). T3-T5 treatments provided higher values (p < 0.05) of lightness (L*). The scanning electron micrographs showed a smooth and homogeneous surface for the T1 and T2 films and a slightly roughened surface for the T3-T5 films. The T1 film had the highest (p < 0.05) tensile strength and elongation at break compared to the other films. Furthermore, X-ray diffraction (XRD) indicated that the structures of the T1, T3, T4 and T5 films were predominantly amorphous. In general, T1 and T4 films were the ideal formulations. They have potential for being used as edible packaging for food, soluble sachets, containers for oils and/or capsules for the delivery of bioactive compounds.