油橄榄叶中羟基酪醇的含量变化规律研究

Variation Rule of Hydroxytyrosol Content in Olive Leaves

以90%甲醇-水溶液为提取剂,用超声波提取不同品种、月份和树龄油橄榄叶中羟基酪醇,采用HPLC方法分析5个品种油橄榄叶中羟基酪醇的含量变化规律,同时考察阿斯、莱星等10种油橄榄叶放置3年后其中橄榄苦苷转化为羟基酪醇的趋势。结果表明:油橄榄叶中羟基酪醇含量一年生长期内有1个高峰期和1个低谷期,5～6月份的含量最高;11～12月份最低;不同树龄和品种间含量差异较大,油橄榄叶中羟基酪醇树龄6年以下含量明显高于18年以上的;6年生鄂植8号幼叶中5月份达到0.768%,6年生九峰6号12月份最低,为0.058%;阿斯、莱星等10种18年以上树龄油橄榄叶放置3年后橄榄苦苷明显减少,羟基酪醇的含量增加1倍,因此大量橄榄苦苷在贮存期被降解为羟基酪醇。

Hydroxytyrosol was extracted from 5 breeds of olive leaves from different tree ages by ultrasonic extraction using 90 % MeOH-H2O and analyzed by HPLC method.Simultaneously,the conversion trend of oleuropein into hydroxytyrosol was investigated from 10 breeds of olive leaves stored over 3 years.Results showed that：content of hydroxytyrosol in a growing year has one high peak period namely May and Jun.,and one low trough period,namely Nov.and Dec..Huge differences existed among different breeds.The content of hydroxytyrosol of 6 years age trees is higher than that of 18 years age.Erzhi No.8 olive leaves of 6 years age in May have the highest hydroxytyrosol content of 0.768 %,in contrary,6 years age Jiufeng No.6 olive leaves in Dec.have the lowest hydroxytyrosol content of 0.058 %.In leaves from 10 breeds of over 18 years age stored over 3 years,the content of oleuropein is greatly reduced,while the content of hydroxytyrosol is doubled.It means that a lot of oleuropein was degraded in hydroxytyrosol during the storage period.