Production and characterization of pullulan/paper/zein laminates as active food packaging materials

Pullulan/paper/zein laminates were developed as food packaging materials with active properties, taking advantage of the hydrophilic character of the pullulan where the rockrose essential was incorporated as a bioactive agent to be more easily released into the packaged food; paper improved the general mechanical properties of the developed materials; and the hydrophobic nature of zein improved the barrier properties of the developed materials. A cohesive microstructure without a clear boundary between the three layers was visualized by Scanning Electron Microscopy, which proves the good adhesion between them. It was found that the incorporation of rockrose essential oil significantly improves the ability of the laminates to inhibit lipid peroxidation. Thus, the potential for application of the developed laminates as new food packaging materials was confirmed, considering their ability to inhibit and/or prevent oxidation and lipid peroxidation, and thereby increase the shelf-life of the packaged food. The laminates also presented antimicrobial activity, specifically against Gram-positive strains. After seven days of storage of fresh ham slices packaged with the developed laminates, it was observed that the texture parameters (shear force and shear energy) increased significantly in pullulan/paper/zein packages with and without the incorporation of rockrose essential oil.