Enhancement of Mass Transfer Intensification for Essential Oil Release from Lavandula pubescence Using Integrated Ultrasonic-Microwave Technique and Enzymatic Pretreatment

This work was designed to utilize the integration of ultrasonic-microwave assisted preceded by enzymolysis pretreatment to enhance the extraction efficiency of essential oil (EO) from wild Lavandula pubescens (Lp). Cellulase (C-ase), hemicellulase (H-ase), and mixed enzymes (C-ase/H-ase) were used at 10 mg/100 mL of the liquid phase. Gas chromatography-mass spectrometry (GC-MS) system was used for chemical composition analyses of Lavandula pubescens essential oil (Lp-EO). C-ase pretreatment achieved the highest yield (0.50%) of EO and highest ratio of carvacrol (29.22%) as the main compound in comparison to other treatments. Changes in the morphological structure of Lp tissues were tracked using scanning electron microscopy (SEM). Free radical-scavenging activity was assessed using DPPH•-SA and ABTS•+-SA assays. The optimal extraction conditions were enzyme concentration of 14.82 mg/100 mL, sonication time of 38.18 min, and microwave power at 333 W. At these conditions, the maximum % yield, % DPPH•-SA, and ABTS•+SA were 0.67%, 65.40%, and 0.025 (as mM Trolox), respectively. Results exhibited that the isolated Lp-EO could be used as anti-free radical and antibacterial agents in the biological systems.本研究旨在采用酶解预处理先行、超声-微波辅助联用的集成提取工艺，提升野生绵毛薰衣草（Lavandula pubescens, Lp）精油（essential oil, EO）的提取效率。实验以液相体系10 mg/100 mL的添加量，分别使用纤维素酶（Cellulase, C-ase）、半纤维素酶（Hemicellulase, H-ase）及复合酶（C-ase/H-ase）进行预处理。采用气相色谱-质谱联用（Gas Chromatography-Mass Spectrometry, GC-MS）系统对绵毛薰衣草精油（Lp-EO）进行化学成分分析。相较于其余处理组，纤维素酶预处理组的精油得率最高（0.50%），且其主要成分香芹酚（carvacrol）的占比亦为各组之最（29.22%）。采用扫描电子显微镜（Scanning Electron Microscopy, SEM）追踪观测绵毛薰衣草组织的形态结构变化。通过1,1-二苯基-2-三硝基苯肼自由基清除试验（DPPH•-SA）与2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸自由基清除试验（ABTS•+-SA），对样品的自由基清除活性进行评估。最优提取工艺参数为：酶添加量14.82 mg/100 mL、超声处理时长38.18 min、微波功率333 W。在此工艺条件下，精油得率、DPPH自由基清除率与ABTS自由基清除率分别可达0.67%、65.40%与0.025（以mM Trolox计）。研究结果表明，所提取得到的Lp-EO可在生物体系中用作自由基清除剂与抗菌剂。