03409nam a2200217 a 450000100080000000500110000800800410001910000220006024501970008226001410027950000440042052025910046465000180305565300140307365300150308770000200310270000140312270000170313670000210315370000170317421823842025-12-13       2025    bl uuuu     u00u1 u    #d1 aSERRANO, L. C. F.  aInfluence of sonication time and power on the physicochemical properties of alginate-based nanoemulsions incorporated with marjoram essential oil (Origanum majorana L.).h[electronic resource]  aIn: SIMPÓSIO LATINO AMERICANO DE CIÊNCIA DE ALIMENTOS E NUTRIÇÃO, 16., 2025, Águas de Lindóia. Anais [...]. Campinas: Galoác2025  aSLACAN 17-19 nov. 2025; Pôster 332593.  aThe inherent limitations of the direct application of essential oils in food products have driven the development and improvement of stabilization strategies for these natural substances prior to use. Marjoram essential oil (MEO) is a natural preservative rich in bioactive compounds with antimicrobial properties, which can be incorporated into emulsions forming active coatings aimed at extending food shelf life. Obtaining emulsions with droplet sizes in the nanometric scale (&lt200 nm) can enhance the stability, transparency, and antimicrobial activity of coatings activated with the essential oil. Therefore, the objective of this study was to evaluate the influence of ultrasonication time and power parameters on the physicochemical properties of alginate-based nanoemulsions incorporating MEO. A primary emulsion composed of water, sodium alginate (1%), MEO (1%) and Tween 80 (1%) was prepared using an Ultra-Turrax at 10,000 rpm for 5 minutes. This emulsion was then subjected to further homogenization using an ultrasonic probe (100% amplitude, 20 kHz) to obtain nanoemulsions. The ultrasonic treatments varied in sonication time (1, 3, and 5 minutes) and the applied power (150 and 250 W). The coating-forming nanoemulsions (CFNs) were characterized in terms of droplet size, polydispersity index, zeta potential (ζ), essential oil retention, whiteness index, turbidity, viscosity, and accelerated stability. All CFNs presented droplet sizes in the nanometric scale, except for the sample treated at 5 min/250 W treatment. Prolonged high-energy treatments increased droplet size and polydispersity while reducing zeta potential to critical values, an effect attributed by the “over-processing” phenomenon, which promotes droplet coalescence. Ultrasonic treatment did not affect oil retention (average 72%). Transparency was associated with oil droplet size, with smaller droplets yielding higher optical transparency. CFNs exhibited Newtonian flow behavior, and prolonged high-energy treatments led to reduced viscosity. Accelerated stability tests showed that only the primary emulsion and the 5 min/250 W sample showed phase separation. Ultrasonic treatments under moderate conditions (3 min/150 W, 5 min/150 W, 1 min/250 W, and 3 min/250 W) were the most effective in producing nanoemulsified systems with stable oil droplets at the nanometric scale, high essential oil retention, good optical transparency, and stability against coalescence and gravity-driven phase separation, demonstrating promising potential for application as active coatings in food products.  aNanoemulsions  aStability  aUltrasound1 aCOSTA, A. M. M.1 aALVES, J.1 aPINTO, J. C.1 aCABRAL, L. M. C.1 aTONON, R. V.