Dávila-Rodríguez M, López-Malo A, Palou E, Ramírez-Corona N, Jiménez-Munguía M T
Chemical, Food and Environmental Engineering Department, Universidad de Las Américas Puebla, Ex-Hacienda Sta. Catarina Mártir S/N, San Andrés, Cholula, 72810 Puebla, Mexico.
J Food Sci Technol. 2020 Nov;57(11):4133-4142. doi: 10.1007/s13197-020-04449-8. Epub 2020 Apr 24.
Essential oils (EOs) have demonstrated antimicrobial activity against bacteria due to the effects of their major components. The direct application of EOs may present a rapid volatilization of its components and can decrease their effectiveness. Encapsulation by means of emulsification can provide protection to lipid compounds on a microscale. The aim of this study was to characterize microemulsions of cinnamon essential oil (CEO), oregano essential oil (OEO), and rosemary essential oil (REO) prepared by high-frequency ultrasound and evaluate their antimicrobial activities against and . The microemulsions (oil-in-water, O/W) of EOs were prepared using high-frequency ultrasound, applying a wave amplitude of 84 µm for 15 min (REO and CEO) or 30 min (OEO). The antimicrobial activity was determined by inoculating 10 CFU/mL of bacteria. Nonsurvival of the bacteria was confirmed by plate count in tryptic soy agar, determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The microemulsions exhibited droplet size diameters of 1.98 to 5.46 µm, showing high encapsulation efficiencies (79.91-81.97%) and low separation rates (2.50-6.67%). The MIC and MBC for the microemulsions for both bacteria were 20-75% less than values obtained for the non-encapsulated EOs. This study demonstrates that high-frequency ultrasound is a suitable technique for obtaining stable microemulsions to deliver natural antimicrobials that can be applied to control bacteria of high relevance in food safety.
由于其主要成分的作用，精油（EOs）已显示出对细菌的抗菌活性。精油的直接应用可能会导致其成分快速挥发，并降低其有效性。通过乳化进行包封可以在微观尺度上为脂质化合物提供保护。本研究的目的是表征通过高频超声制备的肉桂精油（CEO）、牛至精油（OEO）和迷迭香精油（REO）的微乳液，并评估它们对[具体细菌1]和[具体细菌2]的抗菌活性。使用高频超声制备精油的微乳液（水包油型，O/W），对REO和CEO施加84 µm的波幅15分钟，对OEO施加30分钟。通过接种10 CFU/mL的细菌来测定抗菌活性。通过在胰蛋白胨大豆琼脂平板计数来确认细菌的非存活情况，确定最低抑菌浓度（MIC）和最低杀菌浓度（MBC）。微乳液的液滴粒径为1.98至5.46 µm，显示出高包封效率（79.91 - 81.97%）和低分离率（2.50 - 6.67%）。两种细菌的微乳液的MIC和MBC比未包封的精油所获得的值低20 - 75%。本研究表明，高频超声是一种适合获得稳定微乳液以递送天然抗菌剂的技术，这些抗菌剂可用于控制食品安全中具有高度相关性的细菌。
