Antimicrobial films containing microparticles for the enhancement of long-term sustained release

Area of Science:

• Materials Science
• Food Science
• Polymer Chemistry

Background:

• Antimicrobial coatings offer an alternative to traditional preservatives in packaging.
• Microencapsulation controls active agent release for sustained antimicrobial activity.
• Consumer demand for reduced preservative concentrations drives innovation in food packaging.

Purpose of the Study:

• To develop and evaluate thin-film coatings with microencapsulated antimicrobial agents for sustained release.
• To combine microencapsulation and thin-film coating technologies for enhanced product protection.
• To investigate the release mechanisms and duration of phenylethyl alcohol (PEA) from functionalized polyethylene surfaces.

Main Methods:

• Polyethylene surfaces were coated using a dip coating process with polyurethane binder.
• Poly(methyl methacrylate) (PMMA) microparticles loaded with phenylethyl alcohol (PEA) were incorporated into the coating.
• The release of PEA from coated surfaces and microparticles was measured over time to assess sustained release kinetics.

Main Results:

• Coated films (400-1000 µm thickness) exhibited sustained PEA release for over 3 months.
• Diffusion of PEA through the PMMA matrix was identified as the rate-limiting step for release.
• Release rate was influenced by microparticle contact area and film thickness, with increased release observed at larger contact areas and thinner films.

Conclusions:

• Antimicrobial coatings incorporating microencapsulated agents provide effective long-term sustained release.
• This technology meets safety requirements while catering to consumer demand for lower preservative levels.
• Encapsulated antimicrobial agents in thin coatings show significant promise for product preservation throughout their shelf-life.