Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) with Phenolic Acids for Active Food Packaging

Area of Science:

• Materials Science
• Polymer Science
• Food Science

Background:

• Polyhydroxyalkanoates (PHAs), like poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), are biodegradable polymers with potential for food packaging.
• Incorporating natural compounds can enhance polymer properties and add functionality, such as antimicrobial or antioxidant activity.
• Understanding the interaction between additives and the polymer matrix is crucial for developing effective food packaging materials.

Purpose of the Study:

• To develop and characterize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) films incorporating ferulic acid (FA) or p-coumaric acid (PCA).
• To evaluate the impact of FA and PCA on the microstructure, thermal behavior, mechanical, optical, and barrier properties of PHBV films.
• To assess the overall and specific migration of these compounds from the PHBV films into various food simulants.

Main Methods:

• Melt blending and compression molding were used to prepare PHBV films with varying concentrations of FA or PCA (3%, 6%, 9%).
• Microstructural analysis, thermal behavior assessment (e.g., DSC), mechanical testing (e.g., tensile strength, elongation), optical property measurements, and barrier property evaluation (oxygen and water vapor transmission) were performed.
• Migration studies were conducted using different food simulants to quantify the release of FA and PCA.

Main Results:

• Ferulic acid (FA) dispersed homogeneously, while p-coumaric acid (PCA) formed particles in the PHBV matrix.
• Increased concentrations of both FA and PCA enhanced the barrier properties against oxygen and water vapor.
• FA improved film extensibility, whereas high PCA content increased brittleness. Both compounds altered the polymer's crystallization pattern.
• Migration of active compounds was simulant-dependent, with higher release in ethanol-based simulants compared to aqueous systems.

Conclusions:

• PHBV films incorporating FA or PCA exhibit enhanced barrier properties, making them suitable for food packaging applications.
• The specific compound and its concentration influence the film's physical properties and migration behavior.
• These functionalized films have the potential to extend the shelf life of food products by reducing oxygen and water vapor transmission.