316
P. R. Gogate and S. M. Joshi
390 μg/g of fucoxanthin which was reported to be significantly higher as compared
to that obtained using the conventional approach of Soxhlet extraction (50 μg/g)
(Kanda et al. 2014). SCF is reported to be efficient than conventional extraction
processes but finds lesser application as compared to SFE which is also observed to
give higher pigment extraction yields.
13.3.4 Pressurized Liquid Extraction (PLE)
Pressurized liquid extraction consist of using liquid solvents at higher temperatures
(50–200 °C) and pressure (35–200 bar) to extract desired components from biological
materials. Solvents are found to be effective at reduced surface tension and viscosity
prevalent at such conditions resulting in higher solubility and mass transfer rates.
PLE is reported effective in pigment extraction with use of greener solvents like
ethanol or water and intensification benefits of lower extraction time and solvent
requirements (Plaza and Turner 2017). Other reported solvents for PLE are ethyl
acetate, methanol, dichloromethane, propane, n-hexane and ionic liquids (Poojary
et al. 2016). As a specific example, D. salina and H. pluvialis subjected to PLE
with acetone was reported to give pigment extraction same as that of traditional
methods but with significant reduction in time (20 min) and solvent requirement
(Denery et al. 2004). Similarly, study performed by Herrero et al. (2006) reported
that PLE assisted pigment extraction from Dunaliella salina at 160 °C for 17.5 min
gave high yield of pigments as 31.35 mg/100 g using ethanol as solvent (Herrero
et al. 2006). Another study on extraction of β carotene from C. vulgaris reported
0.67 mg/g pigment yield at 116.8 °C and treatment time of 25 min (Kwang et al. 2010).
In the same study, efficiency of PLE was reported to be higher than conventional
solvent extraction process and maceration. Study performed by Koo et al. (2012) on
zeaxanthin extraction from C. ellipsoidea using PLE resulted in 4.28 mg/g at 115.4 °C
treatment for 23.3 min (Koo et al. 2012). Taucher et al. (2016) reported 60 °C and
10 min as the optimised PLE conditions for extraction of 1.48 μg/mg of lutein using
dichloromethane as solvent (Taucher et al. 2016). In summary, it is evident that
PLE is one of the potential processes for pigment extraction demonstrated to be
quite effective at laboratory scale of operation and further investigation is needed to
use PLE at commercial scale. It is also important to understand that the optimum
conditions of temperature, pressure and time need to be established at laboratory
scale for the specific system.
13.3.5 PEF Assisted Extraction
Electric field technologies like pulsed electric field (PEF), moderate electric field
(MEF) and high voltage electric discharge (HVED) can also be effective in pigment
extraction processes. The process is considered to be non-thermal and green with
P. R. Gogate and S. M. Joshi
390 μg/g of fucoxanthin which was reported to be significantly higher as compared
to that obtained using the conventional approach of Soxhlet extraction (50 μg/g)
(Kanda et al. 2014). SCF is reported to be efficient than conventional extraction
processes but finds lesser application as compared to SFE which is also observed to
give higher pigment extraction yields.
13.3.4 Pressurized Liquid Extraction (PLE)
Pressurized liquid extraction consist of using liquid solvents at higher temperatures
(50–200 °C) and pressure (35–200 bar) to extract desired components from biological
materials. Solvents are found to be effective at reduced surface tension and viscosity
prevalent at such conditions resulting in higher solubility and mass transfer rates.
PLE is reported effective in pigment extraction with use of greener solvents like
ethanol or water and intensification benefits of lower extraction time and solvent
requirements (Plaza and Turner 2017). Other reported solvents for PLE are ethyl
acetate, methanol, dichloromethane, propane, n-hexane and ionic liquids (Poojary
et al. 2016). As a specific example, D. salina and H. pluvialis subjected to PLE
with acetone was reported to give pigment extraction same as that of traditional
methods but with significant reduction in time (20 min) and solvent requirement
(Denery et al. 2004). Similarly, study performed by Herrero et al. (2006) reported
that PLE assisted pigment extraction from Dunaliella salina at 160 °C for 17.5 min
gave high yield of pigments as 31.35 mg/100 g using ethanol as solvent (Herrero
et al. 2006). Another study on extraction of β carotene from C. vulgaris reported
0.67 mg/g pigment yield at 116.8 °C and treatment time of 25 min (Kwang et al. 2010).
In the same study, efficiency of PLE was reported to be higher than conventional
solvent extraction process and maceration. Study performed by Koo et al. (2012) on
zeaxanthin extraction from C. ellipsoidea using PLE resulted in 4.28 mg/g at 115.4 °C
treatment for 23.3 min (Koo et al. 2012). Taucher et al. (2016) reported 60 °C and
10 min as the optimised PLE conditions for extraction of 1.48 μg/mg of lutein using
dichloromethane as solvent (Taucher et al. 2016). In summary, it is evident that
PLE is one of the potential processes for pigment extraction demonstrated to be
quite effective at laboratory scale of operation and further investigation is needed to
use PLE at commercial scale. It is also important to understand that the optimum
conditions of temperature, pressure and time need to be established at laboratory
scale for the specific system.
13.3.5 PEF Assisted Extraction
Electric field technologies like pulsed electric field (PEF), moderate electric field
(MEF) and high voltage electric discharge (HVED) can also be effective in pigment
extraction processes. The process is considered to be non-thermal and green with