NANOTECHNOLOGY APPLIED TO Dipteryx alata Vogel (BARU) OIL: DEVELOPMENT OF SOLID LIPID NANOPARTICLES FOR THE PRESERVATION OF BIOACTIVE COMPOUNDS

The oil from the almonds of Dipteryx alata Vogel, popularly known as baru, is a species native to the Brazilian Cerrado that has a high concentration of unsaturated fatty acids and bioactive compounds, such as tocopherols, carotenoids, and polyphenols. Despite its recognized antioxidant properties, the oil is highly susceptible to oxidation, which limits its utilization and economic potential. In this context, solid lipid nanoparticles (SLNs) represent a promising strategy to protect bioactive compounds and improve their bioavailability, contributing to the socioeconomic valorization of baru. The objective of this study was to evaluate the antioxidant activity of baru oil and develop SLNs loaded with the oil, performing their physicochemical characterization. Baru oil (obtained by mechanical pressing and provided by the partner company Atina - Ativos Naturais) was evaluated to determine antioxidant activity using DPPH radical scavenging assay. The SLNs were prepared using the hot high-shear homogenization method, employing stearic acid as the solid lipid, constituting the oil phase, and soy lecithin as the surfactant, composing the aqueous phase. Baru oil was incorporated at a proportion of 10% (w/w) relative to the mass of the melted lipid, before combining the phases. Both phases were heated to 80°C, and the aqueous phase was added to the oil phase under magnetic stirring for 5 min. Subsequently, the emulsion was homogenized in an Ultra-Turrax at 30.000 rpm (five cycles of 1 min), cooled in an ice bath for 50 minutes to induce lipid recrystallization. The solution was frozen and then freeze-dried. The mean hydrodynamic diameter, polydispersity index (PDI), and zeta potential were determined by dynamic light scattering (DLS), using a 0.45 μm filter. Baru oil (100 mg/mL) exhibited 20.43±0.97% antioxidant activity, corroborating results reported in literature and reinforcing the rationale for its encapsulation in SLNs. SLNs exhibited a mean hydrodynamic diameter of 156.3±2.445 nm, a PDI of 0.1182±0.02242, and a zeta potential of -33.11±0.5788 mV. The particle size combined with low PDI, indicates a homogeneous and monodisperse colloidal system. The zeta potential below -30 mV suggests strong electrostatic repulsion between particles, indicating possible physical stability and reducing the tendency toward aggregation during storage. Thus, the antioxidant activity observed in baru oil reinforces the importance of its encapsulation in order to preserve its bioactive properties. The developed SLNs exhibited an appropriate mean hydrodynamic diameter, a narrow size distribution, and a zeta potential that indicates of good colloidal stability, demonstrating their potential as carriers for baru oil. These results provide a basis for future studies evaluating the antioxidant, antiglycation, and anti-aging potential of baru oil and SLNs.

Acknowledgements: São Paulo Research Foundation (FAPESP), Process number: 2025/18421-0.