Antimicrobial PLA-Based Composite Gels with Improved Functional Properties for Food Packaging.

Area of Science:

• Materials Science
• Polymer Science
• Food Science

Background:

• Biodegradable polymers like polylactic acid (PLA) are sought for sustainable food packaging.
• Incorporating antimicrobial functionalities enhances packaging performance and reduces waste.
• Developing multifunctional PLA composites requires careful selection of active agents and fillers.

Purpose of the Study:

• To develop and evaluate multifunctional PLA-based composite films with enhanced properties for food packaging.
• To investigate the impact of different functional fillers (grape pomace, GO-Ag, GO-TiO2, GO) on PLA film characteristics.
• To assess the structural, mechanical, thermal, and antimicrobial performance of the developed PLA composites.

Main Methods:

• Five PLA formulations were prepared: a reference blend and four composites with 0.5 wt.% functional fillers.
• Characterization included antimicrobial activity assays, Vickers hardness testing, Scanning Electron Microscopy (SEM), and Differential Scanning Calorimetry (DSC).
• Statistical analysis (p < 0.05) was used to determine significant differences in mechanical properties.

Main Results:

• Vickers hardness significantly increased with filler incorporation, indicating enhanced stiffness and load transfer.
• PLA composites with silver-graphene oxide (GO-Ag) and titanium dioxide-graphene oxide (GO-TiO2) exhibited improved thermal stability, with transitions shifted to higher temperatures.
• PLA composites containing grape pomace (PLA-GP), GO-Ag, GO-TiO2, and GO demonstrated significant antimicrobial activity, with PLA-GA, PLA-GT, and PLA-GO showing the greatest efficacy.

Conclusions:

• Bioactive and nanostructured fillers effectively enhance the mechanical, thermal, and antimicrobial properties of PLA.
• These multifunctional PLA composites show significant potential for developing sustainable and functional food packaging.
• The study highlights the feasibility of tailoring PLA properties through the incorporation of specific functional fillers for advanced packaging applications.