The effect of cold atmospheric plasma on the micro and macrostructure of freshly harvested essential oil raw materials with the analysis of structural changes has been studied. The essential oil raw materials of laurel leaves, rose petals and rosemary containing the target component in internal essential oil receptacles were chosen as the object of the study. Scanning electron microscopy has shown that the flow of charged particles in a low-temperature plasma makes it possible to form a developed volumetric structure due to electroporation of plant membranes and destruction of the wax surface layer. The targeted effect on the membranes of essential oil globules leads to a change in the capillary-porous structure of the material with the formation of additional pores formed by plasma discharge, oriented along the direction of the electric field strength in the volume of the material. The characteristic size of the formed electrical pores varies from 10-1000 microns and depends on the moisture content of the feedstock and the specific intensity of processing. According to the results of experimental studies, it has been shown that using low-temperature plasma treatment, it is possible to multiply the mass-exchange extraction processes by forming a developed structure of essential oil raw materials. The paper presents an experimental setup for generating low-temperature atmospheric plasma based on thermionic emission using an Agilent 33220A functional generator and a Matsusada 20B20 high-voltage amplifier, which allows generating an output voltage at the anode up to 20 kV. It is established that the nature of the low-temperature plasma flow forms two main effects: the surface effect in the form of "etching" and the penetrating effect with the formation of through channels. For labra leaves (the initial humidity is higher), the diameter of the plasma channel reached 400 microns, whereas for rosemary (lower humidity) it was only 25 microns, which is explained by differences in the dielectric properties and electrical conductivity of the tissues. On the surface of the rose petals, the treatment leads to a smoothing of the microrelief (adaxial epidermis consisting of micropapillaries), which indicates the dominance of the etching effect over the penetration effect. The mechanism of action includes lipid oxidation, membrane electroporation, protein denaturation, and chlorophyll degradation, which is confirmed by the darkening of treated laurel leaves an hour after treatment due to the interaction of oxygen-containing reactive plasma particles with tissues. The data obtained form a hypothesis about the transition of essential oil from a bound form to a free one during plasma treatment, which opens up prospects for creating a new energy-efficient technology for processing essential oil raw materials with a shorter extraction time and an increased yield of target components.

1. Sherstyukov A.G. et al. Recent advances in essential oil extraction using cold plasma treatment. Foods and Raw Materials. 2027. vol. 15. no. 2.

2. Salgueiro L., Martins A.P., Correia H. Raw materials: the importance of quality and safety. A review. Flavour and Fragrance Journal. 2010. vol. 25. no. 5. pp. 253–271. doi: 10.1002/ffj.1973.

3. Vallino M. et al. Impact of drying temperature on tissue anatomy and cellular ultrastructure of different aromatic plant leaves. Plant Biosystems – An International Journal Dealing with all Aspects of Plant Biology. 2022. vol. 156. no. 4. pp. 847–854. doi: 10.1080/11263504.2021.1922535.

4. Basak S., Annapure U.S. Recent trends in the application of cold plasma for the modification of plant proteins – A review. Future Foods. 2022. vol. 5. article 100119. doi: 10.1016/j.fufo.2022.100119.

5. Rathore V., Nema S.K. Methodology on Plasma-Activated Water-Assisted Extraction and Plasma Bubbling-Assisted Hydrodistillation. In: Srivastav P.P., Srivastava B., K.S. (eds.) Essential Oil Extraction from Food By-Products. New York, NY: Springer US, 2025. pp. 123–132. doi: 10.1007/978-1-0716-4634-2_8.

6. Shorstkii I.A. Use of electrophysical methods when processing oil raw materials. Proceedings of Higher Educational Institutions. Food Technology. 2019. no. 4. pp. 11–16. (in Russian).

7. Shorstkii I.A., Khudyakov D.A., Sherstyukov A.G. Application of low-temperature plasma treatment to increase extraction depth and improve the quality of bay laurel essential oil. In: Scientific and Innovative Potential for the Development of Production, Processing, and Application of Essential-Oil and Medicinal Plants in the Eurasian Economic Union: Proceedings of the VII International Scientific and Practical Conference. 2025. pp. 120–125. (in Russian).

8. Das J. et al. Extraction. In: Chemical Engineering Essentials 1. 2025. pp. 263–302. doi: 10.1002/9781394372348.ch9.

9. Shorstkii I.A., Zherlicin A.G., Li P. Impact of pulsed electric field and pulsed microwave treatment on morphological and structural characteristics of sunflower seed. OCL. 2019. vol. 26. article 47. doi: 10.1051/ocl/2019048.

10. Shorstkii I. Application of cold filamentary microplasma pretreatment assisted by thermionic emission for potato drying. Innovative Food Science and Emerging Technologies. 2020. vol. 66. article 102540. doi: 10.1016/j.ifset.2020.102540.

11. Taha A. et al. Pulsed Electric Field: Fundamentals and Effects on the Structural and Techno-Functional Properties of Dairy and Plant Proteins. Foods. 2022. vol. 11. no. 11. article 1556. doi: 10.3390/foods11111556.

12. Sherstyukov A.G., Shorstkiy I.A., Khudyakov D.A. Comparative Characterisation of Lavender Essential Oil Distillation Methods Using Low-Current Spark Discharge Pretreatment. Storage and Processing of Farm Products. 2025. vol. 33. no. 3. doi: 10.36107/spfp.2025.3.665 (in Russian).

13. Konarska A. New insight in secretory structures and secretion composition in Rhus typhina L. – Anatomical, histochemical, and ultrastructural studies. Micron. 2024. vol. 186. article 103692. doi: 10.1016/j.micron.2024.103692.

14. Du Y. et al. Improving food drying performance by cold plasma pretreatment: A systematic review. Comprehensive Reviews in Food Science and Food Safety. 2022. vol. 21. no. 5. pp. 4402–4421. doi: 10.1111/1541-4337.13027.

15. He X. et al. Cold plasma treatment maintains antioxidant capacity and cell membrane integrity in apricot fruit by inducing reactive oxygen species scavenging systems. Postharvest Biology and Technology. 2025. vol. 230. article 113815. doi: 10.1016/j.postharvbio.2025.113815.

16. Shorstkii I., Koshevoi E. Drying Technology Assisted by Nonthermal Pulsed Filamentary Microplasma Treatment: Theory and Practice. ChemEngineering. 2019. vol. 3. no. 4. article 91. doi: 10.3390/chemengineering3040091.

17. Khudyakov D.A., Shorstkii I.A. Influences of cold atmospheric plasma pretreatment on drying kinetics, structural, fractional and chemical characteristics of tobacco leaves. Drying Technology. 2022. vol. 40. no. 15. pp. 3285–3291. doi: 10.1080/07373937.2021.2021230.

18. Durek J. et al. Effect of ultrasound-assisted cold plasma pretreatment on cell wall polysaccharides distribution and extraction of phenolic compounds from hyssop (Hyssopus officinalis L.). International Journal of Biological Macromolecules. 2023. vol. 253. article 123557. doi: 10.1016/j.ijbiomac.2023.123557.

19. Karami M. et al. Exploring the capacity of microorganism treatment for fermentation and glycosidic aroma bioconversion from rose oil distillation wastewater. Chemical and Biological Technologies in Agriculture. 2024. vol. 11. no. 1. article 194. doi: 10.1186/s40538-024-00717-3.

20. Karunanithi S., Guha P., Srivastav P.P. Cold plasma-assisted microwave pretreatment on essential oil extraction from betel leaves: Process optimization and its quality. Food and Bioprocess Technology. 2023. vol. 16. no. 3. pp. 603–626. doi: 10.1007/s11947-022-02957-3.

21. Özdemir E. et al. Cold plasma application to fresh green leafy vegetables: Impact on microbiology and product quality. Comprehensive Reviews in Food Science and Food Safety. 2023. vol. 22. no. 6. pp. 4484–4515. doi: 10.1111/1541-4337.13231.

22.