Novel Biodegradable Nanoparticulate Chain-End Functionalized Polyhydroxybutyrate-Caffeic Acid with...

Area of Science:

• Polymer Chemistry
• Materials Science
• Food Science

Background:

• Polyhydroxyalkanoates (PHAs) have limited bioactivity due to their backbone structure.
• Chemical modification is necessary to enhance the functionality, stability, and solubility of PHAs.

Purpose of the Study:

• To chemically modify polyhydroxybutyrate (PHB) to improve its properties.
• To create novel PHB-based nanoparticles for potential applications in food coatings.

Main Methods:

• PHB was modified via transamination to PHB-diethanolamine (PHB-DEA) and subsequently functionalized with caffeic acid (CafA) to yield PHB-DEA-CafA.
• Characterization involved FTIR and 1H NMR spectroscopy, thermal analyses (TGA, DSC), and biodegradability tests.
• Nanoparticles (NPs) were prepared and characterized for size and stability. Antioxidant and antimicrobial activities were evaluated against food pathogens.

Main Results:

• The modified polymer, PHB-DEA-CafA, exhibited improved thermal stability and enhanced biodegradability (65% in 60 days) compared to PHB (50%).
• PHB-DEA-CafA nanoparticles (NPs) were successfully synthesized with a mean particle size of 223 nm and good colloidal stability.
• The NPs demonstrated significant antioxidant capacity (IC50 = 32.2 mg/mL) and strong inhibition of Listeria monocytogenes (98% in 48 h).
• Coating raw polish sausage with NPs significantly reduced bacterial count.

Conclusions:

• PHB-DEA-CafA represents a novel, functionalized polyester with enhanced biodegradability and potent bioactivities.
• The developed nanoparticles show significant potential as active agents for food coatings, improving food safety and extending shelf life.