Production and characterisation of antioxidant and antibacterial polymeric nanoparticles loaded with Oenocarpus bataua phenolic extract

Abstract

SummaryOne recent trend in the food industry is using natural antioxidants and antimicrobials as additives for developing multi‐functional packaging. In this study, phenolic compounds from patawa (PEP), a neglected Amazon palm tree, were extracted and encapsulated in nanoparticles based on acetylated cashew gum polysaccharide (acCGP) and chitosan (CS) using a nanoprecipitation technique. The primary objective was to evaluate the antioxidant activity and antibacterial properties of PEP and acCGP/CS@PEP. Results from HPLC‐MS showed that PEP is mainly composed of epicatechin, naringenin and rutin. acCGP/CS@PEP nanoparticles showed a spheric and smooth microstructure, observed with 40.1% PEP encapsulation into the nanoparticles. The main encapsulated phenolics were luteolin, quercetin and epicatechin. Also, FTIR spectroscopy, X‐ray diffraction and differential scanning calorimetry analyses evidenced the success of PEP encapsulation. Results from antioxidant activity evidenced that acCGP/CS@PEP has a DPPH scavenging activity 45‐fold higher than the unencapsulated PEP, a 5‐fold higher ferric reducing power and 20‐fold higher antioxidant potential against ABTS. Similarly, acCGP/CS@PEP had higher antibacterial activity against Escherichia coli (MIC = 2.24 mg mL−1), Salmonella enteritis (MIC = 4.48 mg mL−1) and Staphylococcus aureus (MIC = 4.48 mg mL−1). Analysis by SEM evidenced that acCGP/CS@PEP had a potent destructive effect with disruption of the bacterial cell membrane and liberation of cytoplasmic content. These findings demonstrated that PEP could be efficiently encapsulated in acCGP/CS nanoparticles, and this strategy could improve the efficiency of PEP as a bioactive compound for developing active packaging.