Evaluation of mechanical and water barrier properties of transglutaminase cross-linked zein films incorporated with oleic acid

In this study, four concentrations of transglutaminase were used in zein films incorporated with four oleic acid concentrations, and subsequently, the mechanical and water barrier properties were evaluated. Enzyme concentration significantly affected mechanical and barrier properties of the films. Transglutaminase concentration at 1% improved tensile strength of control sample from 17.5 to 26.9MPa while solubility decreased from 6.4% to 4.4%. Incorporation of oleic acid into transglutaminase-treated zein films irrespective of enzyme concentration decreased water vapour permeability and solubility with the 1% transglutaminase-treated zein films incorporated with 3% oleic acid registering the lowest permeability (0.37gmmm(-2)h(-1)kPa(-1)) and solubility (2.8%) values while elongation at break was not significantly improved. The use of transglutaminase at 1% concentration in cross-linking zein films coupled with incorporation of controlled concentrations of oleic acid can be an effective approach in improving mechanical and water barrier properties of zein-based films.