Comparative study of physico-mechanical and antioxidant properties of edible gelatin films from the skin of cuttlefish

Physicochemical properties of edible films based on cuttlefish skin gelatin extracted without (G0) or with different concentrations of pepsins (5 (G5), 10 (G10) and 15 (G15) U/g of skin) were investigated. Edible films prepared with partially hydrolyzed gelatins had lower tensile strength (TS) and elongation at break (EAB), but higher water vapour permeability (WVP) and water solubility than the control film. FTIR spectra of obtained gelatin films revealed a significant loss of molecular order of the triple helix. In addition, differential scanning calorimetric (DSC) analysis indicated that partially hydrolyzed gelatine films exhibited lower transition temperature and enthalpy compared with those of control film. The properties of the films were related to their microstructure, which was observed by scanning electron microscopy. Films with G0 and G5 had a smooth surface and a more compact structure, while films prepared with G10 and G15 had coarser surface. Thus, the chain length of extracted gelatin directly affected the properties of corresponding films.