## 4 Discussion  
In this study, the effects of different non-conventional extraction techniques and process conditions on the efficiency of pyrethrin extraction were investigated. After the extraction of pyrethrins from the Dalmatian pyrethrum plant (_Tanacetum cinerariifolium_) using six novel green extraction techniques, it was found that the amounts of extracted pyrethrins obtained with MAE are very similar between the solvents and between the different extraction temperatures, and the highest amount of total pyrethrins was extracted with 80% ethanol at 70 \({}^{\circ}\)C, which is in accordance with previously published results [15]. Ethanol suitability is ambiguous and can be explained with similarity-interniscibility theory or with suitability for microwave irradiation. According to this theory, ethanol is a suitable solvent because the pyrethrins mentioned are soluble in ethanol, and the more similar the polarity of the solvent and the solute, the faster the dissolution of solute from plant material [29]. Since pyrethrin compounds have a bipolar character, it cannot be claimed that the polarity of the solvents predominantly influences the extraction efficiency. However, the polarity of ethanol influences molecular dipole rotation to a greater extent, which means that it can absorb microwave radiation more efficiently and produce a thermal effect [30,31]. In previous studies, ethanol was shown to be efficient in extracting pyrethroids from lithchi fruit [29] and pyrethrins from Dalmatian pyrethrum flowers [15]. By applying UAE conditions, the amounts of total pyrethrins extracted were up to five times higher than with MAE, with a significant difference (\(p<0.05\)) between the two, i.e., the largest amount of pyrethrins was extracted with 80% MeOH at 70 \({}^{\circ}\)C and then with 80% EtOH, which is consistent with the work of [PERSON] et al. [15], where ultrasound extraction with EtOH was found to be the most suitable for pyrethrin extraction. When comparing these two techniques (MAE and UAE), UAE is more efficient, considering that this technique extracted pyrethrin I and had the highest content of total extracted pyrethrins. HVED-assisted extraction was not efficient in the extraction of pyrethrins since water is not an efficient solvent. The solubility of pyrethrins is due to their physical and chemical properties, including low vapor pressure, low Henry's law constants, and large octanol/water coefficients. Apart from their interaction with polarized light, the enantiomers' physical properties are all the same, except in the case of optical rotation, as the diastereomers have different physical properties (e.g., boiling point, melting point, solubility, etc.) [32]. Although HVED-assisted extraction can change some physical properties of the solvent, this was not sufficient for the successful extraction of the pyrethrins due to their negligible water solubility. The DES proved to be unsuitable for the extraction of pyrethrins, too. This could be due to the fact that the DESs used are very hydrophilic, which is not conducive to the extractability of pyrethrins, as shown in previous techniques. Water as a solvent was not suitable for the extraction of pyrethrins, even at high temperatures, which influenced the change in polarity of the water itself during SWE. Nevertheless, the application of such high temperatures does not have a positive effect on the extraction of pyrethrins. The same was observed in the MAE, where pyrethrins were not extracted in any of the water extracts, regardless of the temperature applied. This emphasizes how crucial the choice of solvent is during extraction and how much the solvent itself influences the selectivity of the process and, ultimately, the extraction of the target component. It is well known that the most active components of pyrethrum extract are pyrethrin I and pyrethrin II.