Enzyme extraction by lab-scale hydrodistillation of ginger essential oil (Zingiber officinale Roscoe): Chromatographic and micromorphological analyses

The present study assessed the use of crude multi-enzymatic extracts (CME) obtained from solid-state fermentation of cocoa bean shells by Aspergillus oryzae ATCC 10124 in the extraction of ginger essential oils, without the use of additional steps, such as drying, which could cause some compounds to volatilize. A Doehlert matrix was used in the optimization of the enzymatic pre-treatment. Independent variables of temperature, time and the proportion of CME/H2O were evaluated. After enzymatic treatment, extraction occurred by hydrodistillation. The results demonstrated that pre-treatment raised essential oil yields by 47.95 % at 40 degrees C, 130 min and CME/H2O (75/425 mL mL(-1)). The composition of the obtained essential oils was identified by gas chromatography mass spectrometry (GC-MS), alpha-zingiberene (25.20 %) being the main volatile constituent. Degradation of the plant cell wall of the ginger was observed through micromorphological analysis. Application of CME in ginger essential oil extraction eliminated the drying stage that is necessary in this type of plant material, reducing both energy consumption of the process and volatilization of the chemical components.