Evaluation of a novel nano-size collagenous matrix film cross-linked with gallotannins catalyzed by laccase.

The effect of hydrolysis degree of gallotannins (GT, 1 mg/g) on cross-linking of nano-size collagen catalyzed by laccase (12 U/g) was studied, and the antibacterial properties of GT hydrolysates (HGT)-laccase (Lac) collagen films on minced cod were also investigated. The results showed that the tensile strength of HGT-Lac films (87.23-100.77 MPa) was higher than those added HGT alone (85.59-95.58 MPa) under the same hydrolysis degree of GT. Compared to the denaturation temperature (78.05 °C) of pure nano-size collagen film without addition of HGT and laccase, the denaturation temperature of HGT (80.75-86.30 °C) and HGT-Lac (91.97-101.64 °C) films increased greatly, especially for HGT-Lac films. Moreover, both HGT and HGT-Lac films showed some mild antibacterial properties for minced cod during storage at 4 °C for 8 days. Therefore, the combination of HGT and laccase could improve the performance of nano-size collagen film and extend the application of collagen in biodegradable/edible packaging.