Abstract
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.
Highlights
In recent years, the study of films based on renewable resources has acquired increased attention
The prepared non-transparent films were of yellow shades, depending on the specific formulation
The main purpose of this study was to develop the optimum film composition based on zein and enriched with various natural bioactive compounds, which do not significantly deteriorate mechanical properties, while simultaneously enhancing the antimicrobial activity
Summary
The study of films based on renewable resources has acquired increased attention. As a renewable plant protein, is a suitable candidate for the preparation of safe and ecologically favorable polymer carriers of bioactive compounds. It is known for its valuable film-forming properties that predetermine its applications as packaging materials [1]. Since protein films can suffer from worse mechanical and barrier properties, some previous studies have focused on overcoming these problems. Khalil et al [1] investigated the effects of natural cross-linkers, such as citric acid, succinic anhydride, and eugenol, on the physical characteristics of solvent-cast zein-based films. An enhancement of the tensile properties was revealed due to the modification of mentioned cross-linking agents
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
