Active Low-Density Polyethylene-Based Films by Incorporating α-Tocopherol in the Free State and Loaded in PLA...

Area of Science:

• Materials Science
• Polymer Science
• Food Science

Background:

• Active food packaging aims to extend shelf life and maintain food quality.
• Incorporating antioxidants like alpha-tocopherol (α-TOC) into packaging materials is a key strategy.
• Polymeric nanoparticles offer a controlled release system for active compounds.

Purpose of the Study:

• To develop active low-density polyethylene (LDPE) films for food packaging.
• To encapsulate alpha-tocopherol (α-TOC) within poly(lactic acid) nanoparticles (PLA NPs).
• To evaluate the effect of α-TOC loaded PLA NPs on LDPE film properties.

Main Methods:

• Nanoprecipitation was used to create α-TOC loaded PLA NPs.
• Freeze-drying and oven-drying were employed for NP drying.
• Blow extrusion was used to incorporate NPs into LDPE films at 10 and 20 g/kg concentrations.
• Scanning electron microscopy (SEM) was used for NP distribution analysis.
• Mechanical testing (tensile strength, Young's Modulus, elongation at break) and water vapor permeability tests were conducted.

Main Results:

• LDPE films with well-distributed PLA NPs containing α-TOC were successfully produced via blow extrusion.
• Mechanical properties showed decreased tensile strength and Young's Modulus, but increased elongation at break.
• Water vapor permeability was reduced in films containing α-TOC and PLA NPs compared to control LDPE films.
• Antioxidant activity was observed in both free α-TOC and encapsulated forms, though encapsulation influenced its behavior.

Conclusions:

• Blow extrusion is a viable method for producing active LDPE packaging films with encapsulated α-TOC.
• Encapsulation of α-TOC in PLA NPs affects the mechanical properties and water vapor barrier of LDPE films.
• The developed active films exhibit antioxidant properties, suggesting potential for extending food shelf life.