Method for attaining rosemary essential oil with differential composition from dried or fresh material

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Process Optimization

Background:

• Rosemary (Rosemarinus officinalis L.) is a historically significant medicinal and essential oil plant.
• Understanding factors influencing essential oil extraction is crucial for its industrial application.

Purpose of the Study:

• To investigate the impact of steam distillation time (DT) and biomass type (dry vs. fresh) on rosemary essential oil yield, composition, and bioactivity.
• To develop predictive models for essential oil yield and composition based on DT.

Main Methods:

• Steam distillation of fresh and dry rosemary biomass at varying distillation times (DT).
• Gas chromatography-mass spectrometry (GC-MS) for essential oil composition analysis.
• ORACoil assay for antioxidant capacity determination.
• Evaluation of antileishmanial, antimalarial, and antimicrobial activities.

Main Results:

• Dry biomass yielded higher essential oil content (0.43%) compared to fresh biomass (0.35%).
• Optimal yield was achieved around 40 min DT, with no benefit from longer times.
• Essential oil composition varied significantly with DT, with key constituents like α-pinene, eucalyptol, and camphor showing distinct elution patterns.
• Rosemary oil demonstrated antioxidant capacity (4,108 μmolVE/L) but lacked significant antileishmanial, antimalarial, or antimicrobial activity.

Conclusions:

• Distillation time is an effective and inexpensive method to modulate rosemary essential oil composition.
• Specific DT can be employed to produce rosemary oils with targeted concentrations of constituents, catering to diverse market demands.
• The study provides insights into optimizing rosemary essential oil extraction for specific applications.