Effect of nanoencapsulation using PLGA on antioxidant and antimicrobial activities of guabiroba fruit phenolic extract.

Guabiroba fruit has been highlighted for its high phytochemical content, particularly of phenolic compounds. The stability, bioavailability, and bioactivity of these compounds can be enhanced by nanoencapsulation, to improve functionality. Poly(d,l-lactic-co-glycolic) acid (PLGA) nanoparticles containing phenolic extract of guabiroba (GPE) were synthesized by an adapted emulsion-evaporation method and their physico-chemical and functional properties were studied at two lactic to glycolic acid ratios (50:50 and 65:35). Higher (P<0.05) or equivalent antioxidant capacity compared to free GPE were observed for GPE-loaded nanoparticles. Free extract and PLGA nanoparticles were effective inhibitors of Listeria innocua, with lower (P<0.05) GPE concentrations required for inhibition when nanoencapsulated. Also, reduction of ROS generation in non-cancer cells was achieved with lower GPE concentrations (P<0.05) after encapsulation. These results suggest that PLGA nanoparticles can be used as a delivery system for phenolic compounds at lower levels than originally required for enhanced functional properties.

Delivery of phytochemicals of tropical fruit by-products using poly (DL-lactide-co-glycolide) (PLGA) nanoparticles: synthesis, characterization, and antimicrobial activity.

Nanoencapsulation offers great potential in natural compounds delivery as it protects them from degradation, improves their aqueous solubility, and delivers active compounds to the action site. Poly (dl-lactide-co-glycolide) (PLGA) nanoparticles of acerola, guava, and passion fruit by-product extracts were synthesized using the emulsion-evaporation method. PLGA with different lactide to glycolide (50:50 and 65:35) ratios were used to determine how polymer composition affected nanoparticles properties and antimicrobial efficiency. Controlled release experiments showed an initial burst followed by a slower release rate for all encapsulated fruit by-products inside PLGA matrix. Nanoparticle properties were more dependent on by-product extract than on PLGA type. Fruit by-products and their nanoparticles were analyzed for antimicrobial activity against Listeria monocytogenes Scott A and Escherichia coli K12. All fruit by-products encapsulated in PLGA inhibited both bacteria at lower (P<0.05) concentration than corresponding unencapsulated fruit by-product. Both PLGA types improved fruit by-products delivery to pathogens and enhanced antimicrobial activity.