## 4 Extraction Methods for Coriander Bioactive Compounds
### Conventional Extraction Methods
#### 4.1.1 Maccation  
A conventional procedure such as maceration (Figure 2), which has been used for a long time, is still relevant even if it is often criticized for its extraction time (few hours) and high temperature (above 80 \({}^{\circ}\)C). Some authors continuously refine this method by adjusting the extraction parameters (solvent type, liquid to solid ratio, etc.) to shorten the extraction period and lower the temperature [99]. Many studies have been devoted to the extraction of secondary metabolites from the coriander plant by this method. Indeed, the study by [PERSON], [PERSON] [82] was the first study using fresh coriander leaves to assess the total phenolic content (TPC) and the antioxidant activity of the acetone extract. The study concluded that coriander is a rich source of antioxidants and TPC and thus could be used as a potent nutraceutical agent in daily foods. In addition, the study conducted by [PERSON], [PERSON] [86] on the phytochrome of the acetone extract of dried coriander  
Figure 2: Common extraction technologies applied to coriander. HD: hydrodistillation; MAE: microwave-assisted extraction; UAE: ultrasound-assisted extraction; SWE: supercritical water extraction; SFE: subcritical fluid extraction. seeds revealed the presence of many secondary metabolites, including flavonoids, which were present in a very high concentration, while tannins, alkaloids, quinines, terpenoids, cardiac glycosides, and phlobatannins were present in low amounts, and saponins were not identified. Moreover, the study conducted by [PERSON], [PERSON] [88] aimed to investigate and compare the genotypic variations and similarities existing among the seventeen genotypes of coriander leaves and seeds collected from the Tarai and Kumaun areas of Uttarakhand state in India. Phytochemical screening revealed the presence in their methanolic extracts of many constituents, including alkaloids, saponins, phytosterols, fixed oils, phenols, tannins, and flavonoids, but the absence of resins and triterpenes. The types of phytoconstituents in the leaves and seeds of the different genotypes were not similar. The study conducted by [PERSON] and [PERSON] [81] highlighted the variability of TPC depending on the coriander part. They observed that the extract of coriander leaves contained a higher amount of TPC and presented higher antioxidant activities than the extract of stem parts. Nevertheless, they reported that the leaves and stems of coriander grown in Saudi Arabia contained good amounts of total phenols (>1.02 mg gallic acid equivalent/100 mL) and showed a free radical scavenging activity higher than 18.3%. In the study conducted by [PERSON], [PERSON] [85] on the methanolic extracts of three coriander fruits, they reported variability in polyphenol, flavonoid, and tannin contents and antioxidant activity among Tunisian, Syrian, and Egyptian varieties. In addition, the study conducted by [PERSON], [PERSON] [87] revealed a variability in TPC according to the type of extraction solvent: hexane, dichloromethane, ethyl acetate, methanol, and water. Indeed, the best content was attributed to the extract obtained by ethyl acetate. A more recent study conducted by [PERSON] and [PERSON] [84] tried to contrast the phenolic profile composition and antioxidant activity of ethanolic and methanolic extracts of coriander seeds. The results showed that the best polyphenol content and antioxidant capacity were obtained with the methanolic extract and 22 phenolic compounds were identified and quantified. The results obtained by these authors can be explained by the fact that good solvent system allows for the optimal extraction of desired compounds without modifying their chemical nature [100], and generally, polar organic solvents are the most effective in bioactive substances solubilizing from plant tissues [101]. The study conducted by [PERSON], [PERSON] [83] brings the information that the vegetative parts showed hydroxycinnamic acids derivatives and flavonoid derivatives (quercetin and kaempfer derivatives) as the main phenolic compounds.