In the present study, a nanoemulsion was developed to improve the functional performance of Thymus capitatus essential oil (thyme EO) as natural food preservative. Thyme EO was submitted to phytochemical prospection and its safety limit was evaluated by acute oral toxicity. Hereafter, the EO was nanoencapsulated and the antioxidant and antibacterial activities of bulk and encapsulated EO were examined. Results showed that concentrations up to 2 g·kg^− 1 b.w. of T. capitatus EO did not present any toxic effects. Moreover, results exhibited an enhancement of nanoencapsulated EO antibacterial activity. In fact, nanoemulsion demonstrated higher growth inhibition diameters than free EO (15.8 and 9.8 mm, against Staphylococcus aureus, respectively). Furthermore, nanoemulsion exhibited significant lower minimum inhibitory concentration against all tested bacteria than bulk EO. However, nanoencapsulating T. capitatus EO decreased significantly its antioxidant activity. Indeed, for DPPH test, free EO IC₅₀ concentrations were considerably lower than those of the nanoencapsulated form (300 and 390 μg·mL^− 1, respectively). As well, the capacity of T. capitatus EO to inhibit the β-carotene bleaching has been reduced after its nanoencapsulation. These results provide useful information for designing effective natural preservative able to inhibit food bacterial spoilage.

在本研究中，纳米乳剂的开发是为了改善的功能性能胸腺capitatus精油（百里香EO）作为天然食品防腐剂。百里香EO被纳入植物化学研究领域，并通过急性口服毒性评估其安全性极限。此后，将EO纳米封装，并检查本体和封装的EO的抗氧化和抗菌活性。结果表明，最高浓度为2 g·kg ^-1  bw的人参T. EO没有任何毒性作用。而且，结果显示出纳米封装的EO抗菌活性的增强。实际上，纳米乳剂对金黄色葡萄球菌的生长抑制直径比游离EO（15.8和9.8 mm）高， 分别）。此外，与所有EO相比，纳米乳液对所有测试细菌的最低抑菌浓度均显着降低。然而，nanoencapsulating T. capitatus EO显著降低其抗氧化活性。实际上，对于DPPH测试，游离EO IC _50的浓度明显低于纳米囊封形式的浓度（分别为300和390μg·mL ^-1）。还有，容量T. capitatus EO抑制β胡萝卜素漂白已被其纳米包封后减少。这些结果为设计能够抑制食物细菌变质的有效天然防腐剂提供了有用的信息。