EFFECT OF GRUMIXAMA LEAVES EXTRACT ADDITION IN NANOEMULSION PRODUCED BY LOW ENERGY METHOD

Grumixama (Eugenia brasiliensis) leaves are a by-product of Agroforestry Systems (AFS) management in Santa Catarina State, Brazil. However, this material may present great potential for technological and sustainable use in the food, chemical, or pharmaceutical industry. Thus, this study aimed to evaluate the antioxidant (FCRC and DPPH) and antimicrobial potential of grumixama leaves extracts (GLE) and produce nanoemulsion (NE) loaded with GLE, evaluate their stability (size, polydispersity index, zeta potential, and pH) and morphology (TEM). GLE was produced with methanol 80% at 40°C for 1h, and lyophilized. The oil-in-water (O/W) NE were produced by the spontaneous emulsification method using grape seed oil, GLE, egg lecithin in the organic phase, and P123 in the aqueous phase. GLE at the concentration of 0.6 mg mL-1 showed antioxidant activity corresponding to 269.9 ± 17.2 mg GAE L-1 for FCRC, and 995.9 ± 1.9 µM L-1 for DPPH. GLE showed antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes) and Gram-negative (Salmonella Typhimurium, and Escherichia coli) bacteria, with a maximum inhibition zone of 12.5 ± 0.0 mm for S. aureus. The GLE-loaded NE had 89% encapsulation efficiency, nanometer size (183.7 ± 4.5 nm), low PDI (0.177 ± 0.02), negative zeta potential (-37.4 ± 4.0) and pH of 5.32 ± 0.35, evaluated after 24h of production. These values remained stable over 130 days of storage at 4°C and, therefore, the formulation is kinetically stable. The droplets formed are morphologically spherical, with a well-defined and compact structure near the outer layer. These results indicate that GLE has potential for application in nanotechnology formulations, which meets the demand for natural and sustainable food ingredients.