Development of pea protein nanocarriers for encapsulation of orange essential oil by nanoprecipitation

In the present study, pea protein isolate (Pisum sativum) based nanoparticles were synthesized and characterized for the encapsulation of orange essential oil, aiming at the development of sustainable systems for the protection and controlled release of bioactive compounds. The growing demand for plant-based functional ingredients has driven research on vegetable proteins, which offer advantages such as low allergenic potential, good emulsifying properties, and alignment with sustainability trends. The nanoparticles were produced by the nanoprecipitation method, using pea protein as the structuring material and Pluronic as a steric stabilizer. Two formulations were prepared: a control dispersion containing only pea protein and Pluronic, and a second formulation containing orange essential oil dissolved in ethanol. The samples were characterized by dynamic light scattering (DLS), determining the mean hydrodynamic diameter (Z-average), polydispersity index (PDI), and zeta potential. The results showed that the control dispersion presented particles with an average size of 201.87 ± 2.29 nm, a PDI of 0.29, and a zeta potential of −17.33 mV, indicating a relatively homogeneous and stable nanoscale system. In contrast, the formulation containing essential oil exhibited an increase in particle size, reaching 599.23 ± 34.42 nm, along with higher polydispersity (PDI = 0.61) and a reduction in zeta potential to −9.13 mV. These findings demonstrate that oil incorporation promoted significant structural changes, increasing system heterogeneity and reducing electrostatic repulsion between particles. Particle size distribution analysis indicated that the orange oil-loaded formulation exhibited more heterogeneous particle populations, favoring phenomena such as Ostwald ripening and making system stability dependent on the formation of a robust interfacial film. Conversely, the control sample displayed a narrow and uniform size distribution, demonstrating that the interaction between pea protein and Pluronic is capable of generating stable nanocarriers through steric stabilization. It can be concluded that nanoprecipitation is a feasible technique for obtaining pea protein nanoparticles intended for the encapsulation of lipophilic compounds. Although the incorporation of orange essential oil increased particle size and polydispersity, the results demonstrate promising potential for food and pharmaceutical applications. Future studies should focus on process optimization, encapsulation efficiency, and the evaluation of the thermal stability of the system.

Acknowledgments: IFSC Edital 03/2025/PROPPI – PIPCIT IT and FINEP CHAMADA PÚBLICA MCTI/FINEP/FNDCT/Ação Transversal/CT Agro 01/2024.