Stage 3

Investigation of micro-wave effect on essential oils from the seasoning plants studied

The objectives of this stage were:

3.1. Monitoring of essential oils compositions and morphological changes in irradiated plants compared to the reference plants
3.2. Selection of methods for bioactive compounds extraction from aromatic plants considered for the study
To achieve this objective are taken into account the following activities:
3.1.1. Cultivation and growing of a new lot of plants
3.1.2. Obtaining the essential oils extracts from irradiated and reference plants
3.1.3. Quantitative and qualitative determination of essential oils from obtained extracts, using GC and HPLC techniques
3.1.4. Ultrastructural and morphologic analyses on new lot of studied plants and comparing of obtained results

Conclusions

• Volatile oils content varied depending on the type of compound and the plant, but on the whole, increased in irradiated plants with microwaves frequency in GSM range, while the effect of microwaves operating frequency in WLAN was less clear.
• In Petroselinum crispum, GSM microwave irradiation produced an increasing in the amount of several individual compounds among which the most important were: 3-hexen-1-ol, myrcene, α-phelalndrene, β- phelalndrene, mirysticin and apiol. In comparison with the reference, the apiol content increased more than seven times. WLAN frequency microwaves have led in this plant to increasing of α-pinene, β- phelalndrene, mirysticin and apiol content.
• In Apium graveolens, both types of microwaves have led to increased the content in 3-hexen-1-ol. Irradiation with microwaves frequency in WLAN led to reduction of myrcene (19%) and α-ocimene amount (21%).
• The strongest effects were observed in the case of volatile oils from Anethum graveolens. In irradiated Anethum graveolens with microwaves frequency in GSM was observed an increasing in the content of: β-pinene, α- phelalndrene and dillapiol. However, microwaves frequency in WLAN have caused a decreasing in α- phelalndrene, mirysticin and dillapiol content; the highest decrease was observed for myristicin (approximately 18% of reference plants content).
• Ultrastructural and morphological analyzes led to conclusion that irradiation with WLAN microwaves frequency stress more powerful plants than GSM microwaves frequency.