Abstract
Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) containing 40 wt % Gly (UF40) had elongation at break (ε, %) of 19%. Washed films (WFs) had high tensile strength (σ > 46 MPa) and low elongation at break (ε, <5.0%), enabling their use in food packaging applications. The polymers’ self-assembling occurred during the washing, increasing the stiffness. The XPS analysis suggests that some HCl is lost during the drying process, resulting in a low acid content on the UF surfaces. The UF40 (at 5.0 mg/mL) exhibits cytocompatibility toward mammalian cells and antimicrobial and anti-adhesive properties against Escherichia coli. The remaining HCl in the UF40 can be a disadvantage for food packaging applications; the UF40 (∅ = 8.5 mm; 55 μm thickness) releases H3O+/HCl, reducing the pH to approximately 3.0 when kept in 200 mL distilled water for approximately 30 min. Therefore, we propose the use of UF40 to coat commercial food packaging. The UF40 has low permeability to water vapor and oxygen and works as a barrier against ultraviolet light. The UF40 is also colorless and completely transparent. The UF40 maintained tomatoes’ structural integrity for 18 days at room temperature with no oxidation or microorganism contamination. This paper presents a critical viewpoint concerning chitosan-based films with antimicrobial activities.
Highlights
Bio-based materials can be used as food packaging materials because they can be cytocompatible, and biodegradable, and can replace the use of non-biodegradable, petroleum-based materials in the manufacturing of conventional plastics [1]
CHT should be partly removed from the films in the washing step because they are prepared from polymer blends in an aqueous HCl solution (0.10 M)
When the unwashed films were added to water (200 mL), the pH measured after 30 min was approximately 3.0
Summary
Bio-based materials can be used as food packaging materials because they can be cytocompatible, and biodegradable, and can replace the use of non-biodegradable, petroleum-based materials in the manufacturing of conventional plastics [1]. Biodegradable-based films and coatings comprise only between 5% and 10% of the current plastics market. Polysaccharides have been used to develop food packages, including starch [4], cellulose [5], chitosan (CHT) [6,7], and alginate [8]. Chitosan-based films have advantages over other polysaccharide-based films because they can exhibit antimicrobial activity [7,9]. This feature can increase food’s shelf-life by preventing microbial growth
Sign-in/Register to view highlights & summary 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.
