葉からの精油抽出と抽出液からのポリフェノール回収の最適化と特性評価

Optimization and Characterization of Microwave-Assisted Hydro-Distillation Extraction of Essential Oils from Leaf and Recovery of Polyphenols from Extract Fluid.

• Ao Shang
• Ren-You Gan
• Jia-Rong Zhang
• Xiao-Yu Xu
• Min Luo
• Hong-Yan Liu
• Hua-Bin Li

抄録

本研究では、葉から精油を抽出するためのマイクロ波アシスト水洗蒸留法(MAHD)の効率と抽出液からのポリフェノールの回収について検討した。抽出効率に及ぼすマイクロ波出力、液体と材料の比率、抽出時間の影響については、中央複合設計法に基づく応答曲面法(RSM)の他に、単因子試験を用いて検討した。最適抽出条件は、マイクロ波出力786.27W、液材比7.47:1mL/g、抽出時間35.57分であった。最適条件での精油の収量は3.26±0.05%()、ポリフェノール類の回収量は4.97±0.02mgガロン酸当量/g乾燥重量であった。さらに、包括的二次元ガスクロマトグラフィー-飛行時間型質量分析法(GC×GC-TOFMS)を用いて、生葉と落葉の精油の特性評価を行い、159の個別化合物が暫定的に同定され、それぞれ全含有量の89.68％以上、87.88％以上を占めていた。主な成分としては、精油で初めて同定されたサビネン、l-β-ピネン、β-ミルセン、α-テルピネオール、3-ヘプタノン、β-スジエンのほか、δ-テルピネオール、3-ヘプタノンが挙げられる。結論として、MAHD法は精油を高効率で抽出することができ、同時に抽出液からポリフェノール類を得ることができ、葉の利用率を向上させることができた。

In this study, the efficiency of microwave-assisted hydro-distillation (MAHD) to extract essential oil from leaf, and the recovery of polyphenols from extract fluid were investigated. The effects of microwave power, liquid-to-material ratio, and extraction time on the extraction efficiency were studied by a single factor test as well as the response surface methodology (RSM) based on the central composite design method. The optimal extraction conditions were a microwave power of 786.27 W, liquid-to-material ratio of 7.47:1 mL/g, and extraction time of 35.57 min. The yield of essential oil was 3.26 ± 0.05% (), and the recovery of polyphenols was 4.97 ± 0.02 mg gallic acid equivalent/g dry weight under the optimal conditions. Furthermore, the comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) was used to characterize the essential oils of fresh and fallen leaves, and 159 individual compounds were tentatively identified, accounting for more than 89.68 and 87.88% of the total contents, respectively. The main ingredients include sabinene, l-β-pinene, β-myrcene, α-terpineol, 3-heptanone, and β-thujene, as well as δ-terpineol and 3-heptanone, which were first identified in essential oil. In conclusion, the MAHD method could extract essential oil from with high efficiency, and the polyphenols could be obtained from the extract fluid at the same time, improving the utilization of leaf.