Biocomposite Active Whey Protein Films with Thyme Reinforced by Electrospun Polylactic Acid Fiber Mat

Area of Science:

• Food Science and Technology
• Materials Science
• Polymer Science

Background:

• Electrospinning is a key technique for creating nano/microfibers that enhance composite material properties.
• Agri-food applications can benefit from advanced composite materials with improved functionalities.
• Whey proteins and thyme essential oil (TEO) offer bio-based solutions for active food packaging.

Purpose of the Study:

• To create and characterize one-side-active composite films using whey protein (WF), TEO, and electrospun polylactic acid (PLA) fibers.
• To evaluate the impact of different electrospinning configurations (single vs. dual needle, time) on film properties.
• To assess the potential of these composite films as active packaging for food products, particularly hard cheese.

Main Methods:

• Fabrication of composite films (WF/G1-G4) via electrospinning of PLA onto whey protein films functionalized with TEO.
• Characterization using Scanning Electron Microscopy (SEM) for fiber distribution and film thickness.
• Fourier Transform Infrared Spectroscopy (FTIR) to analyze chemical structure and functional groups.
• Evaluation of barrier properties (octanol permeability, water vapor permeability - WVP) and mechanical properties (tensile strength).
• Assessment of antimicrobial and antioxidant activities against specific foodborne microorganisms and free radicals.

Main Results:

• SEM confirmed uniform PLA fiber mat distribution and increased PLA layer thickness with longer electrospinning times and dual-needle setup (WF/G4).
• FTIR spectra indicated structural integrity and functional group presence, with WF/G4 showing a distinct PLA fingerprint.
• WF/G4 exhibited significantly reduced octanol permeability (1.41% of WF/G1) and lower WVP (33.73% of WF/G1) compared to other films.
• WF/G4 demonstrated the highest tensile strength (2.70 times higher than WF/TEO) and retained approximately 50% of TEO volatile compounds.
• All developed films showed comparable antimicrobial effects against Bacillus cereus, Geotrichum candidum, and Rhodotorula glutinis, alongside good antiradical activity.

Conclusions:

• The developed whey protein/PLA/TEO composite films offer enhanced mechanical strength and barrier properties, crucial for active food packaging.
• The WF/G4 configuration, utilizing dual-needle electrospinning, proved most effective in improving film performance.
• These bioactive films show significant potential as primary packaging materials for hard cheese, providing antimicrobial and antioxidant benefits while preserving volatile compounds.