减压水蒸气蒸馏法提取薰衣草精油的提取动力学研究

建立动力学模型，研究减压水蒸气蒸馏法提取薰衣草精油的提取动力学规律；采用气相色谱-质谱联用，分析测定主要成分芳樟醇、乙酸芳樟酯等在提取过程中的相对含量动态变化，比较不同蒸馏时间获得精油的品质。结果表明，减压水蒸气蒸馏提取薰衣草精油过程的动力学模型y=4.292 5(1-e^{-0.017 9x})，气质联用共解析挥发性成分48 种，芳樟醇、乙酸芳樟酯等为主要挥发性成分，随着提取时间的延长，芳樟醇相对含量由49.51%降至16.78%，下降趋势明显。实验发现该动力学模型可较好地模拟薰衣草精油提取过程的规律，并且结合精油品质分析，前120 min的提取率达1.88%，组分基本稳定；120 min后，提取率增长趋势变缓，且主要成分芳樟醇相对含量明显下降，组分种类复杂。研究认为薰衣草精油减压提取最佳时间为120 min，既可保证提取率较高，又可获得品质优良的精油，且节约提取时间。

Study on extraction kinetics of lavender essential oil extractionby vacuum steam distillation

A kinetic model was established to study the extraction kinetics of lavender essential oil under vacuum steam distillation. Gas chromatography-mass spectrometry (GC-MS) was used to analyze and measure the dynamic content changes in the main components, i.e., linalool andlinalyl acetate, during the extraction process, and to compare the quality of essential oils obtained at different distillation times. Results show that the dynamic model of the lavender essential oil extraction process under vacuum steam distillation was y=4.292 5(1-e^{-0.017 9x}). GC-MS analysis revealed 48 volatile components in the oil, where linalool, linalyl acetate, etc. were the main volatile components. With the extension of extraction time, the linalool content decreased from 49.51% to 16.78%, with a significant downward trend. The experiment revealed that the kinetic model can appropriately simulate the law of essential oil extraction process. Combined with the analysis of essential oil quality, the extraction rate of lavender essential oil under reduced pressure for the first 120 min reached 1.88% and the components were basically stable. Subsequently, the extraction rate increased more slowly, the main component linalool decreased significantly, and the components became more complicated. This research suggests that the optimal time for extraction of lavender essential oil is 120 min, which can ensure a high extraction rate, obtain good quality essential oils, and save extraction time.