*2.3.1.2.2 SFE assisted by cold pressing (SFEAP)*

SFEAP is a novel technique of extraction recently developed by Johner and collaborators [43]. It integrated both the cold-pressed extraction method and the SFE technique. Here, the solid raw material is loaded inside the extraction vessel, and

**81**

**Figure 7.**

**Figure 6.**

*flow control valves.*

*Terpenoids as Important Bioactive Constituents of Essential Oils DOI: http://dx.doi.org/10.5772/10.5772/intechopen.91426*

*Caryocar brasiliense*, and clove (**Figure 7**) [43–45].

a cold pressing is provided by contracting an under pressure piston with the raw material. SFEAP has been shown to offer faster extraction rate at 333 K and 40 MPa with the best yield [44]. Its advantages include gain of extraction time and solvent consumption. This technique has been used to extract EOs from *Foeniculum vulgare*,

*Flow diagram of SC-CO2 extraction [40]. (1) CO2 cylinder, (2) cooling bath, (3) pump, (4) compressor, (5) oven, (6) extractor vessel, (7) monitor, (8) collecting bottle, (9) flowmeter, and (10) CO2 outlet. V1–V6*

*Schematic diagram of SFEAP apparatus [43]. (1) CO2 reservoir; (2) CO2 filter; (3) safety valve; (4) cooling bath; (5) air-driven CO2 pump; (6) control (air flow); (7) air filter; (8) air compressor; (9) heating bath; (10) serpentine tube; (11) extraction cell; (12) 1° extract collecting vessel; (13) 2° extract collecting vessel; (14) flowmeter (15) flow totalizer, V2 back pressure; V5 micrometering valve; V(1,3,4) blocking* 

*valve; P(1,2,3,4) pressure gauge; I1 temperature indicator; I2 temperature indicator.*

**Figure 5.** *Cold pressing apparatus and procedure distillation method [34, 38].*

*Terpenoids as Important Bioactive Constituents of Essential Oils DOI: http://dx.doi.org/10.5772/10.5772/intechopen.91426*

a cold pressing is provided by contracting an under pressure piston with the raw material. SFEAP has been shown to offer faster extraction rate at 333 K and 40 MPa with the best yield [44]. Its advantages include gain of extraction time and solvent consumption. This technique has been used to extract EOs from *Foeniculum vulgare*, *Caryocar brasiliense*, and clove (**Figure 7**) [43–45].

#### **Figure 6.**

*Essential Oils - Bioactive Compounds, New Perspectives and Applications*

*2.3.1.2 Innovative techniques of extraction (nonconventional)*

EOs obtained by conventional methods (**Figure 6**) [40–42].

*2.3.1.2.2 SFE assisted by cold pressing (SFEAP)*

*Cold pressing apparatus and procedure distillation method [34, 38].*

*2.3.1.2.1 Supercritical fluid extraction*

(**Figure 5**).

applied temperatures [37]. The quality of the obtained oil is damaged, particularly if the extraction time is long. It is important that the extraction method maintain the chemical composition and the natural proportion at its original state. Strictly speaking, conventional methods are not the only way for the removal of EOs. Novel techniques known as innovative have been developed for this purpose but may not necessarily be widely used for commercial production due to the high cost of production of oils without any alteration of their thermosensitive components

It is a process of separating one component (the extractant) from another (the matrix) using supercritical fluids as the extracting solvent. In practice, more than 90% of all analytical supercritical fluid extraction (SFE) is performed with carbon dioxide (CO2) as the most used fluid. The CO2 is chosen for several reasons including the following: relatively low critical pressure (74 bars) and temperature (32°C), inertness, non-toxic, nonflammable, high soluble, non-corrosive, safe, available in high purity at relatively low cost, perfect conditions for thermosensitive compounds extraction, selectivity for desired compounds, and easy removal from the extract. At lower temperatures, to avoid potential damage of desired components of EOs, supercritical CO2 extraction technique is highly recommended [39, 40]. Extraction of EOs by SFs, particularly with CO2, provides products free of toxic waste, having a higher quality (especially it reserves the thermal instability of compounds) than

SFEAP is a novel technique of extraction recently developed by Johner and collaborators [43]. It integrated both the cold-pressed extraction method and the SFE technique. Here, the solid raw material is loaded inside the extraction vessel, and

**80**

**Figure 5.**

*Flow diagram of SC-CO2 extraction [40]. (1) CO2 cylinder, (2) cooling bath, (3) pump, (4) compressor, (5) oven, (6) extractor vessel, (7) monitor, (8) collecting bottle, (9) flowmeter, and (10) CO2 outlet. V1–V6 flow control valves.*

#### **Figure 7.**

*Schematic diagram of SFEAP apparatus [43]. (1) CO2 reservoir; (2) CO2 filter; (3) safety valve; (4) cooling bath; (5) air-driven CO2 pump; (6) control (air flow); (7) air filter; (8) air compressor; (9) heating bath; (10) serpentine tube; (11) extraction cell; (12) 1° extract collecting vessel; (13) 2° extract collecting vessel; (14) flowmeter (15) flow totalizer, V2 back pressure; V5 micrometering valve; V(1,3,4) blocking valve; P(1,2,3,4) pressure gauge; I1 temperature indicator; I2 temperature indicator.*
