Variability of the Volatile Organic Compounds of Achillea millefolium L. According to the Collection Time, Type of Polyethylene Packaging and Storage Period

The collection time could be an important target for optimizing technological processes in obtaining essential oils of interest to agribusiness. The objective of this study was to distinguish the time for the collecting of Achillea millefolium L. leaves, which provides the highest yield and quality of the essential oil. Also, identify the type of polyethylene packaging and leaf storage period during the one-year period that would maintain the essential oil characteristics. Gas chromatography-mass spectrometry and chemometric studies were performed into two steps trial to detect changes in chemical profile induced by different conditions. First, an analysis of the leaf collection time was performed using chromatographic data from six different gathering times throughout the day. After determining the best time to collect from the leaves, the essential oil was extracted in five storage periods over a year. The highest oil content was observed in leaves harvested between 11 and 15 h, with a maximum of 39 min after 13 h. Therefore, it is recommended to perform extraction in the early afternoon. There was no significant statistical differentiation related to polyethylene packages. In addition, it is recommended that the essential oil can be stored without significant changes for up to six months.

采集时间对于优化农业综合企业所关注的精油提取工艺而言，或是一项关键优化目标。本研究旨在确定欧蓍草（Achillea millefolium L.）叶片的最佳采集时段，以获取产量最高、品质最优的精油；同时明确在为期一年的储存周期内，可维持精油固有特性的聚乙烯包装类型与叶片储存时长。本研究采用两步试验方案，结合气相色谱-质谱联用法（Gas chromatography-mass spectrometry）与化学计量学分析，以检测不同条件下精油化学组分谱的变化。第一步，基于当日6个不同采集时段的色谱数据，开展叶片采集时间的相关分析。在确定最佳叶片采集时段后，将采集得到的叶片按照一年周期内的5个储存时段分别储存，随后提取精油。试验结果显示，于11时至15时之间采收的叶片精油含量最高，其中13时后39分钟时达到峰值。据此建议在午后早些时候开展叶片采收与精油提取工作。聚乙烯包装类型未对精油品质产生显著统计学差异影响。此外，研究结果表明，精油可在无显著品质变化的前提下储存长达6个月。