## 4 Extraction Methods for Coriander Bioactive Compounds
### Conventional Extraction Methods
#### 4.1.2 Soxhlet Extraction  
Soxhlet seems to be the most adapted technique for extracting the aerial parts of plants in terms of yield (Figure 2). However, it should be emphasized that this extraction technique is conducted at high temperature and allows fibers to be co-extracted [102]. Moreover, the different solvents used can modify the yield of the extraction process [103]. Although Soxhlet extraction is effective at the lab scale, it has major drawbacks: it requires large volumes of solvents, consumes high energy, and is therefore not attractive for industrial applications [104]. In contrast, unconventional methods, such as microwave assisted extraction (MAE) and ultrasound-assisted extraction (UAE), have recently attracted growing interest in both academic and industrial fields [105]. These processes are faster and more efficient than conventional methods, saving energy and reducing extraction costs [106]. In addition, several studies have confirmed these advantages, showing that MAE [107, 108, 109] and UAE [102, 110] outperform Soxhlet extraction in terms of efficiency, with higher yields, shorter extraction times, and reduced energy consumption, making these techniques more suitable for industrial applications. The study conducted by [PERSON] and [PERSON] [96] on the methanolic and aqueous extracts of coriander polyphenols found that the aqueous extract contained the highest levels of polyphenols compared to the methanolic one. Nevertheless, the best antioxidant activities were attributed exclusively to the methanolic extract. On the other hand, most of the investigations using the Soxhlet extraction method were dedicated to the extraction of apolar compounds, mainly oils from coriander seeds. So, the coriander seed powder phytochemicals EO was also obtained via the Soxhlet extraction method using different solvents (water, ethanol, petroleum benzene, methanol, chloroform). Phytochemical analysis revealed the presence of bioactive compounds such as flavonoids, phenols, terpenoids, and alkaloids in all extracts. While the chloroform extract at different concentrations (20, 30 and 40 \(\mu\)L) was tested for its antibacterial activity, it was found to have an inhibitory effect on _Escherichia coli_ and _Pseudomonas aeruginosa_ but not on _Staphylococcus aureus_[95]. Moreover, the study conducted by [PERSON], [PERSON] [93] revealed that coriander seeds have a substantial oil yield (12.30%) and C18:1 fatty acid content (sum of petroselinic and oleic acid), but the lauric acid content was low. It was also found to have a high level of sterols and significant levels of the triterpenes \(\alpha\)- and \(\beta\)-amyrin. On the other hand, when evaluating the effectiveness of the extraction methods (Soxhlet extraction, shaking-assisted extraction, and pressurized liquid extraction (PLE) at 25 and 100 \({}^{\circ}\)C) in terms of seed oil yield and bioactive compounds content, the results revealed that the highest oil yields were obtained via the conventional methods (Soxhlet extraction and shaking-assisted extraction at room temperature). Meanwhile, the highest contents of total sterols and triterpenes were obtained via PLE at 100 \({}^{\circ}\)C.  
The Soxhlet extraction process was also applied to extract oil from coriander to study oil accumulation and fatty acid composition during fruit development (from flowering to maturity) and the effects of climatic conditions on these characteristics during two growing seasons. The results showed that in 2010, compared with 2011, the fruit contained 2% more oil, while the opposite was true for petroselinic acid (PA) content. Thus, these results imply that higher PA concentrations can be obtained by harvesting the fruit before full maturity [94]. The above studies highlight the Soxhlet extraction technique for aerial plant parts, emphasizing its efficiency in terms of yield despite high temperatures and the co-extraction of fibers. This method is particularly useful for extracting apolar compounds such as coriander seed oils.