Liposomal encapsulation of Campomanesia xanthocarpa extracts: antioxidant activity and physicochemical characterization

The valorization of native brazilian species has attracted increasing scientific interest due to their potential as sources of bioactive compounds with functional properties and technological applications. Among these species, Campomanesia xanthocarpa known as guabiroba, a fruit native to southern Brazil, stands out because of its content of phenolic compounds, vitamin C, and other antioxidant substances. However, the application of these compounds may be limited by their instability when exposed to environmental factors such as light, oxygen, and temperature variations. In this context, liposomal encapsulation emerges as a promising strategy to protect bioactive compounds, enhance their stability, and preserve their functional properties. The present study aimed to obtain hydroalcoholic extracts of Campomanesia xanthocarpa, encapsulate them in liposomes, evaluate their antioxidant activity over time, and characterize the physicochemical properties of the resulting particles. The extracts were obtained by maceration of the fruit in a 70% (v/v) hydroalcoholic solution, followed by filtration and concentration of the extract. Encapsulation was performed using the thin-film hydration method, employing soybean lecithin and cholesterol at a 70:30 ratio. After the formation of the lipid film, it was hydrated with the fruit extract, followed by ultrasonication and centrifugation to obtain the liposomes. Antioxidant activity was determined using the DPPH free-radical scavenging assay, with analyses performed on the day of preparation and after four days of storage. The results demonstrated an average encapsulation efficiency of 90% and high initial antioxidant activity for both samples, with free-radical scavenging percentages of 80.8% for the free extract and 84.9% for the encapsulated extract. After four days, a reduction in antioxidant activity was observed in both systems; however, the encapsulated sample showed greater preservation of activity, maintaining 55.1% inhibition, whereas the non-encapsulated extract retained only 26.9%. These findings highlight the protective effect provided by liposomes, reducing the degradation of bioactive compounds. Particle characterization confirmed the formation of liposomes, as observed by microscopy, with an average size of 1174 ± 207 nm determined by dynamic light scattering (DLS). The polydispersity index of 0.93 ± 0.08 indicated a heterogeneous size distribution, while the zeta potential of −3.9 ± 0.1 mV suggested a tendency toward particle aggregation. Despite these limitations, the results demonstrated the feasibility of liposomal encapsulation as a strategy to enhance the stability of antioxidant compounds present in guabiroba. Therefore, this study contributes to the valorization of native brazilian species and highlights future application prospects in the food, pharmaceutical, and cosmetic industries.

Acknowledgments: IFSC Edital Nº 12/2025/PROPPI/DAE, CNPq and FAPESC 15/2023 TO2023TR001418, FAPESC 15/2023 TO2023TR001518, FAPESC 21/2024 – Programa de Pesquisa Universal TO2024TR002655.