Department of Food Engineering, Süleyman Demirel University, 32260 Isparta, Turkey.
J Sci Food Agric. 2010 Jan 30;90(2):205-9. doi: 10.1002/jsfa.3788.
The aim of this research was to determine essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.) leaves harvested during the months of June to September.
The maximum essential oil yield in the leaves appeared in the middle of July. The main components of oregano oil were carvacrol, thymol, gamma-terpinene, p-cymene, alpha-terpinene and alpha-pinene. Carvacrol was highest in the July harvest. The maximum extract yield was found in September. Oil distilled from early-season (June) harvested leaves had the highest antioxidant ability, expressed as low concentration providing 50% inhibition of free radical scavenging activity and high levels of reducing/antioxidant capacity. Twelve phenolic compounds of oregano extract were identified and the main components were found to be rosmarinic acid and acecetin. The maximum rosmarinic acid and acecetin were found in harvests of July and June, respectively. Total phenolic contents, free radical scavenging activities and reducing/antioxidant capacities were found to be highest in the July harvest.
All yields, chemical compositions, free radical scavenging activities and reducing/antioxidant capacities of extracts and essential oils of Turkish oregano changed importantly depending on vegetative periods of growing season.
本研究旨在确定 6 月至 9 月期间收获的土耳其牛至（Origanum onites L.）叶的精油成分、酚类成分和抗氧化特性。
叶中精油的最大产量出现在 7 月中旬。牛至油的主要成分是香芹酚、百里酚、γ-萜品烯、对伞花烃、α-萜品烯和α-蒎烯。7 月收获的牛至中香芹酚含量最高。最大提取物产量在 9 月发现。从早期（6 月）收获的叶子中蒸馏出的油具有最高的抗氧化能力，表现为提供 50%自由基清除活性抑制的低浓度和高水平的还原/抗氧化能力。鉴定了牛至提取物中的 12 种酚类化合物，主要成分是迷迭香酸和乙酰丁香酮。7 月和 6 月的收获中分别发现迷迭香酸和乙酰丁香酮含量最高。7 月收获的总酚含量、自由基清除活性和还原/抗氧化能力最高。
土耳其牛至的所有产量、化学成分、自由基清除活性和提取物及精油的还原/抗氧化能力都随着生长季节的不同而重要变化。
