Detalhes do Documento

Natural surfactants have emerged as a nontoxic alternative to prepare nanoemulsions with different food and nonfood applications. The current research explored the use of saponins extracted from Quillaja lancifolia a less studied South American species as natural emulsifiers for basil essential oil nanoemulsions, offering a sustainable alternative to synthetic surfactants. Oil-in-water (O/W) nanoemulsions were formulated using basil essential oil and sunflower oil, optimized via experimental design, and produced by a high-energy method. Characterizations included droplet size distribution, zeta potential, storage stability, surface tension, transmission electronic microscopy (TEM), and antifungal activity. Dynamic light scattering (DLS) results yielded mean droplet diameters (Z-average) below 174.1 ± 2.9 nm, polydispersity indexes (PDI) under 0.30, and highly negative zeta potentials ( 55 mV), ensuring physical stability. TEM analysis confirmed predominantly spherical droplets with a mean diameter of 56.3 nm, consistent with the nanoscale domain observed by DLS. Formulations with a surfactant-to-oil ratio (SOR)  1.0 and an essential oil/sunflower oil (EO/SFO) ratio of 3:7 remained stable for at least 120 days. The optimized formulation displayed significant antifungal activity against two major spoilage fungi, Rhizopus stolonifer MUM 19.02 and Botrytis cinerea MUM 10.138 strains, as determined by minimum inhibitory concentration (MICs) assays, outperforming free basil essential oil under the same conditions. The increase in antifungal activity can be attributed to the better dispersion, prolonged stability, and possible complementary effects between saponins and basil oil terpenes. These results highlight the potential of Q. lancifolia-stabilized nanoemulsions as natural and effective antifungal agents for food preservation applications.