Abstract Thymol is widely recognised as an antibacterial compound. However, its use in food technology is hindered by its high volatility, its light sensitivity and its low solubility in water. To overcome these drawbacks, the preparation of nanoparticles using polylactic acid (PLA) is proposed in this study. The average size of the nanoparticles and thymol encapsulation efficiency parameters were studied using different PLA and thymol concentrations. Furthermore, the morphology, the storage stability of the nanoparticles at several pHs and the in vitro thymol release profile were also studied, as well as their thermal degradation profile. Finally, their antimicrobial activity on a real food model was measured, using for this purpose apple pieces previously inoculated with E. coli. The PLA was found to be the key variable in optimizing the nanoparticle preparation, producing spherical nanoparticles with a thymol encapsulation efficiency of 60.3 ± 8%. These nanoparticles showed a high storage stability at several pHs and improved antimicrobial properties in comparison with the non-encapsulated thymol.

中文翻译：

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负载百里酚的可生物降解的平面纳米颗粒的生产和表征以提高其抗菌作用

摘要 百里酚是公认的抗菌化合物。然而，它在食品技术中的应用受到其高挥发性、光敏感性和在水中的低溶解度的阻碍。为了克服这些缺点，本研究提出了使用聚乳酸 (PLA) 制备纳米颗粒。使用不同的 PLA 和百里酚浓度研究了纳米颗粒的平均尺寸和百里酚包封效率参数。此外，还研究了纳米颗粒在几个 pH 值下的形态、储存稳定性和体外百里酚释放曲线，以及它们的热降解曲线。最后，测量了它们对真实食物模型的抗菌活性，为此目的使用先前接种过大肠杆菌的苹果片。发现 PLA 是优化纳米颗粒制备的关键变量，可生产出百里酚封装效率为 60.3 ± 8% 的球形纳米颗粒。与未封装的百里酚相比，这些纳米颗粒在几个 pH 值下显示出高储存稳定性和改进的抗菌性能。