ABSTRACT
SOLVENT-FREE MICROWAVE EXTRACTION AND MICROWAVEASSISTED
HYDRODISTILLATION OF ESSENTIAL OILS FROM
SPICES
Bayramoglu, Beste
M.S., Department of Food Engineering
Supervisor: Assoc. Prof. Dr. Serpil Sahin
Co-Supervisor: Assoc. Prof. Dr. S. Gü / lü / m Sü / mnü / September 2007, 130 pages
The undesirable effects of conventional methods generated the need for
economical and safe techniques in the extraction of essential oils.
Microwave-assisted hydrodistillation (MAHD) and solvent-free microwave
extraction (SFME) are recently developed techniques, which are thought
to overcome this problem.
Oregano (Origanum vulgare L.), laurel (Laurus nobilis L.) and rosemary
(Rosmarinus officinalis L.) were chosen in this study since they have high
antimicrobial and antioxidant effects and are widely grown and consumed
in Turkey.
The objectives of this study were to examine the applicability of SFME in
the extraction of essential oils from oregano and laurel, and MAHD in the
extraction of rosemary essential oil. The effects of microwave power and
extraction time on the yield, composition, and other quality parameters of
the extracts were also investigated. Hydrodistillation was performed as
control.
SFME offered significantly higher essential oil yields (0.054 mL oil/g
oregano) from oregano as compared to hydrodistillation (0.048 mL oil/g
oregano). Conventional process time was reduced by 80%. Main aroma
compound was thymol (650-750 mg thymol/mL oil).
For laurel, no significant differences were obtained in yields (about 0.022
mL oil/g laurel) obtained by SFME and hydrodistillation. Process time was
reduced by 55-60%. Main aroma compound was 1,8-cineole (630-730 mg
1,8-cineole/mL oil).
In the case of rosemary, no significant differences were obtained in yields
(about 0.026 mL oil/g rosemary) obtained by MAHD at 622 W and
hydrodistillation. The process time was reduced by about 65%. Main
aroma compounds were 1,8-cineole (430-500 mg 1,8-cineole/mL oil) and
camphor (150-210 mg camphor/mL oil).
Keywords: Solvent-free microwave extraction (SFME), Microwave-assisted
hydrodistillation (MAHD), Origanum vulgare L., Laurus nobilis L.,
Rosmarinus officinalis L.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12608874/index.pdf |
| Date | 01 September 2007 |
| Creators | Bayramoglu, Beste |
| Contributors | Sahin, Serpil |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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