Improved microstructure and properties of the gelatin film produced through prior cross‐linking induced by horseradish peroxidase, glucose oxidase and glucose

Abstract

SummaryThe effects of prior enzymatic cross‐linking of bovine gelatin via horseradish peroxidase, glucose oxidase and glucose on microstructure and properties of the target film (cross‐linked gelatin film) were assessed. The cross‐linked gelatin film exhibited similar film thickness and moisture content, lower water solubility and higher opacity than the gelatin film directly prepared with bovine gelatin. The cross‐linked gelatin film also demonstrated improved thermal stability and mechanical properties, characterised by higher melting point and glass transition temperature, enhanced tensile strength and elongation at break and greater storage modulus. Prior gelatin cross‐linking resulted in 30.2% and 68.6% reductions in water vapour and CO2 permeability of the cross‐linked gelatin film, respectively, but did not affect oil permeability. Furthermore, the cross‐linked gelatin film possessed smaller cross‐sectional voids (diameter 100−360 nm vs. 200−595 nm) than the bovine gelatin film. This study shows that cross‐linking can efficiently improve film microstructure and properties of the gelatin‐like products.