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

- Encapsulation with PLGA preserved the extract's phenolic content and bioactivity.
- Encapsulation enhanced phenolic extract's antimicrobial activity.
- Equivalent or lower phenolic extract concentrations were required for antioxidant activity once encapsulated.
- Nanoparticles can be used as a delivery system for enhanced functional properties.
- PLGA 65:35 lactic to glycolic acid ratio showed the best results for phenolic extract encapsulation.

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.