Gelatin was dissolved in double distilled water at 50 °C for 60 min. Films were obtained on the bottom of Petri dishes (diameter 6 cm) after water evaporation at RT from 10 ml of gelatin solution. Films were prepared from solutions at 30% (w/v) gelatin concentration in double distilled water or in 60/40 vol.% acetic acid/double distilled water. Alternatively, films were obtained from 10 ml of 30% (w/v) gelatin in 60/40 vol.% acetic acid/double distilled water, with the addition of 60 mg of genipin dissolved in 0.5 ml of ethanol and 1 ml of 0.75 M PBS, pH 7.4. Films for Fourier transform infra-red (FTIR) analysis were prepared from the same gelatin solutions as above after dilution at 1:20.