Effect of Enzymatic, Ultrasound, and Reflux Extraction Pretreatments on the Chemical Composition of Essential Oils

Molecules. 2020 Oct 20;25(20):4818. doi: 10.3390/molecules25204818.

Abstract

The effect of different hydrodistillation pretreatments, namely, reflux extraction, reflux extraction with the addition of cell wall-degrading enzymes, and ultrasound, on the yield and chemical composition of essential oils of sage, bay laurel, and rosemary was examined. All pretreatments improved essential oil yield compared to no-pretreatment control (40-64% yield increase), while the oil quality remained mostly unchanged (as shown by statistical analysis of GC-MS results). However, enzyme-assisted reflux extraction pretreatment did not significantly outperform reflux extraction (no-enzyme control), suggesting that the observed yield increase was mostly a consequence of reflux extraction and enzymatic activity had only a minute effect. Thus, we show that ultrasound and reflux extraction pretreatments are beneficial in the production of essential oils of selected Mediterranean plants, but the application of enzymes has to be carefully re-evaluated.

Keywords: Clevenger hydrodistillation; GC-MS analysis; Laurus nobilis L.; Rosmarinus officinalis L.; Salvia officinalis L.; cell wall-degrading enzymes; reflux extraction pretreatment; ultrasound pretreatment.

MeSH terms

  • Gas Chromatography-Mass Spectrometry
  • Oils, Volatile / chemistry*
  • Oils, Volatile / isolation & purification
  • Oils, Volatile / radiation effects
  • Plant Leaves / chemistry*
  • Plant Leaves / radiation effects
  • Plant Oils / chemistry
  • Plant Oils / isolation & purification*
  • Plant Oils / radiation effects
  • Rosmarinus / chemistry*
  • Rosmarinus / radiation effects
  • Ultrasonic Waves

Substances

  • Oils, Volatile
  • Plant Oils