The effects of EGCG on the mechanical, bioactivities, cross-linking and release properties of gelatin film

The effects of (−)-epigallocatechin gallate (EGCG) on the mechanical, antioxidative, antimicrobial, cross-linking and release properties of gelatin film were evaluated. The biofilm exhibited excellent antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli in the presence of EGCG at more than 3%. With the increasing content of EGCG (1%-5%), higher denaturation temperature (66.5-84.6 °C) and bloom strength (609.3-1114.7 g) and denser microstructure suggested the existence of cross-linking bonds in the biofilm. The infrared spectroscopy, protein pattern and release property of EGCG showed that hydrogen bonds were the main driving force for cross-linking of the biofilm. The release of EGCG from the biofilm system was described and two compounds were cross-linked via hydrogen bonds. Thus, this study confirmed the improvement on mechanical, bioactivities and release properties of the biofilm was most likely due to the interactions between gelatin and EGCG.