Zein is renewable plant protein with valuable film-forming properties that can be used as a packaging material. It is known that the addition of natural cross-linkers can enhance a film's tensile properties. In this study, we aimed to prepare antimicrobial zein-based films enriched with monolaurin, eugenol, oregano, and thyme essential oil. Films were prepared using the solvent casting technique from ethanol solution. Their physicochemical properties were investigated using structural, morphological, and thermal techniques. Polar and dispersive components were analyzed using two models to evaluate the effects on the surface free energy values. The antimicrobial activity was proven using a disk diffusion method and the suppression of bacterial growth was confirmed via a growth kinetics study with the Gompertz function. The films' morphological characteristics led to systems with uniform distribution of essential oils or eugenol droplets combined with a flat-plated structure of monolaurin. A unique combination of polyphenolic eugenol and amphiphilic monoglyceride provided highly stretchable films with enhanced barrier properties and efficiency against Gram-positive and Gram-negative bacteria, yeasts, and molds. The prepared zein-based films with tunable surface properties represent an alternative to non-renewable resources with a potential application as active packaging materials.

• Keywords
• antibacterial activity, essential oils, eugenol, film, mechanical properties, monoglyceride, wettability, zein,
• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Antifungal Agents pharmacology   MeSH
• Biomechanical Phenomena drug effects   MeSH
• Calorimetry, Differential Scanning MeSH
• Escherichia coli drug effects   MeSH
• Eugenol pharmacology   MeSH
• Laurates pharmacology   MeSH
• Microscopy, Atomic Force MeSH
• Monoglycerides pharmacology   MeSH
• Food Packaging * MeSH
• Oils, Volatile pharmacology   MeSH
• Steam MeSH
• Permeability MeSH
• Surface Properties MeSH
• Wettability MeSH
• Spectroscopy, Fourier Transform Infrared MeSH
• Staphylococcus aureus drug effects   MeSH
• Zein pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Antifungal Agents MeSH
• Eugenol MeSH
• Laurates MeSH
• Monoglycerides MeSH
• monolaurin MeSH Browser
• Oils, Volatile MeSH
• Steam MeSH
• Zein MeSH

Poly(ethylene oxide) (PEO)-like thin films were successfully prepared by plasma-assisted vapor thermal deposition (PAVTD). PEO powders with a molar weight (Mw) between 1500 g/mol and 600,000 g/mol were used as bulk precursors. The effect of Mw on the structural and surface properties was analyzed for PEO films prepared at a lower plasma power. Fourier transform (FTIR-ATR) spectroscopy showed that the molecular structure was well preserved regardless of the Mw of the precursors. The stronger impact of the process conditions (the presence/absence of plasma) was proved. Molecular weight polydispersity, as well as wettability, increased in the samples prepared at 5 W. The influence of deposition plasma power (0-30 W) on solubility and permeation properties was evaluated for a bulk precursor of Mw 1500 g/mol. The rate of thickness loss after immersion in water was found to be tunable in this way, with the films prepared at the highest plasma power showing higher stability. The effect of plasma power deposition conditions was also shown during the permeability study. Prepared PEO films were used as a cover, and permeation layers for biologically active nisin molecule and a controlled release of this bacteriocin into water was achieved.

• Keywords
• controlled permeation, nisin, plasma polymerization, poly (ethylene oxide),
• Publication type
• Journal Article MeSH