DryDIST - The Microwave ClevengerTM
Labstation for rapid Solvent-Free Microwave Extraction of essential oils
The new DryDIST microwave labstation takes advantage
of the unique SFME technology developed at the
Laboratory of Chemistry of Natural Substances and Food
Sciences at the University of Reunion, to provide
researchers with an innovative, rapid extraction method
for essential oils.
Rapid Extraction
The first essential oil
droplets appear after 5-8
minutes against 60-90 minutes
by hydrodistillation (HD). Thirty
minutes with SFME provides
comparable yields to
those obtained with 3-6 hours
by HD
High Purity Extracts
Reduction of both extraction
time and amount of water
reduces deterioration of
compounds and presence of
byproducts
Results Comparable to HD
SFME provides extracts with
to HD chemical compositions
comparable to HD (International Patent Pending)
The SFME Technology
SFME is a microwave accelerated dry distillation
process for extraction of essential oils from aromatic
herbs, spices and dry seeds.
SFME is not a conventional microwave
extraction which utilizes polar or non-polar
solvents nor a modified HD.
The DryDIST
The DryDIST is a laboratory engineered microwave
labstation combining state-of-the-art microwave
hardware with an advanced computer controlled
infrared temperature system and with SFME
technology.
The plant material is placed in a microwave reactor
in the absence of any solvent or water. The
microwave-generated heating of the water molecules
within the plant material distends it causing the gland
and oleiferous receptacles to burst. The essential
oils are freed and stripped away by azeotropic
distillation with the evaporating "in-situ" water of the
plant material. A cooling system outside the
microwave cavity continuously condenses the
distillates. The condensates are guided to a bypass
and the excess water is refluxed back to the sample
in the reactor. Complete distillation is carried out in
approximately 20-30 minutes for aromatic herbs and
40-60 minutes for spices.
|
AROMATIC PLANTS |
Solvent-free
Microwave Extraction |
Hydro-distillation |
Comparsion
Ratio (%)
MW/HD |
Time (min) |
Yield (%) |
Time (min) |
Yield (%) |
|
| Rosmarinus
officinalis |
12 |
0.286 |
180 |
0.167 |
171 |
| Mentha
crispa |
12 |
0.72 |
180 |
0.044 |
164 |
| Thymus
vulgaris |
12 |
0.273 |
180 |
0.169 |
162 |
| Ocimum
basilicum |
12 |
0.010 |
180 |
0.008 |
125 |
|
- The qualitative and quantitative composition of the essential oils obtaioned by HD and SFME are identical
- 20 compounds have been identified by GC-MS for both hydrodistillation and SFME
Advantages of DryDIST
A publication presented at the ISEO Meeting, Wuerzburg,
September 2003, reaches the following conclusions:
The yields of essential oils obtained by the SFME method were usually identical
than those obtained by conventional hydro-distillation. The extraction of the first
essential oil droplets begin only after 5 min. with SFME against 60 to 90 min. for
HD. Thus, an extraction time of 30 min. with SFME provides comparable yields
to those obtained after 3 to 6 hours by means of HD and allows substantial
saving of energy: Solvent-free microwave extraction and hydro-distillation
provide extracts with chemical compositions qualitatively similar. The reduction
of the extraction time and the amount of water in SFME method reduce the
deterioration (hydrolysis, trans etherification or oxidation) and the presence of byproduct.
SFME essential oils are enriched in major compounds compared to HD.
**Solvent-free Microwave Extraction: A Prospective Tool for Rapid Extraction of Essential Oils
M.E. Lucchesi1, F. Chemat1, J. Smadja1, F. Visinoni2
1 Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Université de la
Réunion, La Réunion, France D.O.M.; 2 Milestone Srl, Italy
