Abstract：
The present study evaluates the chemical compositions and antioxidant and antipathogenic properties of commercial orange (Citrus sinensis (L.) Osbeck) essential oils obtained using the cold-press method (EOP) and the cold-press method followed by steam distillation (EOPD). The chemical compositions of the volatilizable fractions, determined by gas chromatography-mass spectrometry, were similar in both samples. A relatively large amount of γ-terpinene was found in the EOPD (1.75%) as compared to the EOP (0.84%). Monoterpene hydrocarbons with limonene (90.4-89.8%) followed by myrcene (3.2-3.1%) as the main compounds comprised the principal phytochemical group. The non-volatile phenolics were eight times higher in the EOP than in the EOPD. Several assays with different specificity levels were used to study the antioxidant activity. Although both essential oils presented similar reducing capacities, the radical elimination ability was higher for the EOP. Regarding the antipathogenic properties, the EOs inhibited the biomass and cell viability of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. Furthermore, both EOs similarly attenuated the production of elastase, pyocyanin, and quorum-sensing autoinducers as assessed using Gram-negative bacteria. The EOP and EOPD showed important antioxidant and antipathogenic properties, so they could represent natural alternatives to extend the shelf life of food products by preventing oxidation and contamination caused by microbial spoilage.
摘要：
本研究评估了商品橙的化学成分以及抗氧化和抗致病性（Citrussinensis（L.）Osbeck）使用冷压方法（EOP）和冷压方法随后进行蒸汽蒸馏（EOPD）获得的精油。可挥发部分的化学成分，通过气相色谱-质谱法测定，在两个样本中相似。与EOP(0.84%)相比,在EOPD中发现相对大量的γ-萜品烯(1.75%)。以柠檬烯（90.4-89.8％），其次是月桂烯（3.2-3.1％）为主要化合物的单萜烃构成了主要的植物化学基团。EOP中的非挥发性酚类物质比EOPD中的高八倍。使用具有不同特异性水平的几种测定来研究抗氧化活性。虽然两种精油都表现出相似的还原能力，EOP的自由基清除能力较高。关于抗致病性，EO抑制金黄色葡萄球菌和铜绿假单胞菌生物膜的生物量和细胞活力。此外，两种EO类似地减弱了弹性蛋白酶的产生，绿脓苷,和使用革兰氏阴性细菌评估的群体感应自诱导物。EOP和EOPD显示出重要的抗氧化和抗致病性，因此，它们可以代表天然替代品，通过防止微生物腐败引起的氧化和污染来延长食品的保质期。
