Download Martinez J.L. (Ed.) Supercritical Fluid Extraction of Nutraceuticals and Bioactive Compounds (CRC, 2007)(ISBN 0849370892)(420s) PDF

TitleMartinez J.L. (Ed.) Supercritical Fluid Extraction of Nutraceuticals and Bioactive Compounds (CRC, 2007)(ISBN 0849370892)(420s)
Tags Solubility Phase (Matter) Supercritical Fluid Phase Rule
File Size6.7 MB
Total Pages420
Table of Contents
                            Front cover
Dedication
Contents
Preface
Acknowledgments
Contributors
Editor
Chapter 1. Fundamentals of Supercritical Fluid Technology
Chapter 2. Supercritical Extraction Plants: Equipment, Process, and Costs
Chapter 3. Supercritical Fluid Extraction of Specialty Oils
Chapter 4. Extraction and Purification of Natural Tocopherols by Supercritical CO2
Chapter 5. Processing of Fish Oils by Supercritical Fluids
Chapter 6. Supercritical Fluid Extraction of Active Compounds from Algae
Chapter 7. Application of Supercritical Fluids in Traditional Chinese Medicines and Natural Products
Chapter 8. Extraction of Bioactive Compounds from Latin American Plants
Chapter 9. Antioxidant Extraction by Supercritical Fluids
Chapter 10. Essential Oils Extraction and Fractionation Using Supercritical Fluids
Chapter 11. Processing of Spices Using Supercritical Fluids
Chapter 12. Preparation and Processing of Micro- and Nano-Scale Materials by Supercritical Fluid Technology
Index
Back cover
                        
Document Text Contents
Page 2

Supercritical
Fluid Extraction

of Nutraceuticals
and Bioactive
Compounds

7089_C000.indd 1 10/22/07 12:02:14 PM

Page 210

Supercritical Fluid Extraction of Active Compounds from Algae 193

other hand, C27 and C29 in the extracts decreased proportionately during the extrac-
tion progress, while C31 alkadiene proportion increased [35]. Hydrocarbon fraction
increased with pressure: the initial concentration of hydrocarbons increased more
steeply than that of intracellular lipids, leading to extracts more rich in hydrocarbons
at higher pressures [55].

6.2.2 chlorella Vulgaris

Chlorella vulgaris microalgae are carotenoid producers (mainly of canthaxanthin
and astaxanthin) [56]. Carotenogenesis can be induced through saline, luminous,
or nutritional stress. On the other hand, the content in carotenoids can be tailored
through the duration of the process and the intensity of the imposed stresses.

Carotenoids belong to a hydrocarbon class (carotenes) and their oxygenated
derivatives (xanthophylls). Their basic structure, reflecting its synthesis path, con-
sists of eight isoprenoid units, which are assembled in such way that two methyl
groups near the molecule center are in position 1,6, while the other methyl groups
stay in position 1,5 [57]. The set of conjugated double bonds (eleven to thirteen) con-
stitutes the chromophore responsible for the color of these compounds. These colors
range from yellow to red and are influenced by the presence of more double bonds,
functional groups, and the type of molecular conformation.

Canthaxanthin (β-β-carotene-4,4’-dione), C40H52O2, a red pigment, together with
astaxanthin, is one of the most important keto carotenoids [13]. It is used as colorant
to improve the color of poultry meats and egg yolks as well as in aquaculture to give
a pink tonality to salmon and trout flesh. Although lacking pro-vitamin A activity,
canthaxanthin has anticarcinogenic capacity [58].

0

20

40

60

80

0 20 40 60 80 100
CO2/Dry Alga (kg/kg)

H
yd

ro
ca

rb
on

s/
D

ry
A

lg
a

(g
/k

g)


FIgure 6.2  Hydrocarbons supercritical extraction yield, as a function of solvent-algae
ratio, from the microalgae Botryococcus braunii in supercritical CO2 at 313.1 K. ♦ 12.5 MPa,
⦁ 20.0 MPa, ◾ 30.0 MPa, × hexane extraction. (Source: Mendes et al., Inorganica Chimica
Acta, 356, 328, 2003. With permission.)

7089_C006.indd 193 10/8/07 11:55:57 AM

Page 211

194 Supercritical Fluid Extraction of Nutraceuticals and Bioactive Compounds

These microalgae were submitted to supercritical CO2 at pressures between 10.0
and 35.0 MPa and temperatures of 40ºC and 55ºC. The extractions were carried out
on 5 g of freeze-dried Chlorella at several physical conditions of the microalgae: not
crushed (whole), partially crushed, and totally crushed cells [34, 35].

The initial concentration of lipids (as determined by the slope of the cumula-
tive curve of the extraction at origin) in supercritical fluid increased with pressure,
for both temperatures, either with whole or crushed cells, but with the latter the
increase was more significant (Figure 6.3). Above 15.0 MPa, there was an initial
concentration increase with temperature for whole cells, but with the crushed algae,
that value was around 25.0 MPa. For crushed cells, the highest value for this con-
centration was obtained at 35.0 MPa/55ºC (19 mg/L CO2) and the lowest (3 mg/L) at
20.0 MPa/55ºC. This pressure was the lowest used for crushed cells. For whole cells,
the highest concentration obtained was 5 mg/L CO2 at 35.0 MPa/55ºC. This behavior
can be related to the different amount and type of lipids available in the supercritical
CO2, according to the physical condition of the algae.

For the conditions of pressure and temperature studied, using whole cells, the global
yield of lipids obtained increased either with the pressure at constant temperature or
with temperature at constant pressure (20.0 and 35.0 MPa) [34]. With crushed cells at
20.0 MPa, the yield decreased with temperature, whereas at 35.0 MPa, it increased.

The highest yield of lipids obtained by SFE was 13.3% (dry weight, partial
crushed cells) at 35.0 MPa/55ºC; this value dropped to 5% at the same conditions
using the whole algae. The yield of organic solvent extraction for crushed cells using
acetone and hexane were 16.8% and 18.5%, respectively.

The extraction of carotenoids showed a similar behavior to that of lipids for pres-
sure and temperature variations. However, the yield of carotenoids was higher with
supercritical CO2 at 35.0 MPa (50 mg/100 g dry weight algae) than that obtained

Pressure (MPa)

C
on

ce
nt

ra
tio

n
(m

g/
L)

205

5

10

15

20

0
35 50

FIgure 6.3  Initial concentration of lipids in CO2 at standard temperature and pres-
sure (STP), as a function of pressure. Whole cells, ◾ 40°C, ⦁ 55ºC. Crushed cells, ♦ 40°C,
▲ 55°C. (Source: Mendes, R.L. and Palavra, A.F., in Chemistry, Energy, and the Environment,
Sequeira, C.A.C. and Moffat, J.B., Eds., Royal Society of Chemistry, Cambridge, 51, 1998.
With permission.)

7089_C006.indd 194 10/8/07 11:56:00 AM

Page 419

402 Supercritical Fluid Extraction of Nutraceuticals and Bioactive Compounds

Triglycerides, 69
Trilinolein, 89–90
Triple point, 2
Trolox Equivalent Antioxidant Capacity (TEAC),

286
Trout, 143
Tuberose volatile oil, 318
Tucuman, 248
Tuna oil, 172, 175
Turbines, 46–47
Turmeric
bioactive compounds from, 244, 251, 343, 345
solubility of essential oils from, 364
therapeutic benefits of, 341
Tween-80, 223
Type V phase behavior, 9–10

U
Ucuuba, 248
Ultrasound, 223
Ultraviolet radiation, 145
Unani, 338
Urea crystallization, 152–156
Urea inclusion complexation, 155–156
Urea-fatty acid ratio, 152–154

V
Valves, 39–41
Vanilla, 346, 359, 360
Vanillin, 359
Vapor pressure, 149–150
Vapor-liquid equilibrium (VLE), 7
Vegetable matrices, 18–19
Vegetable oils, 17, 84–90
Vessels, 29, 34, 35–37

Vetivergrass, 247
Vinca, 251
Viscosity, 1, 4, 32, 134–136
Vitamin A, 146, 160, 178–181
Vitamin E, 277, 281–282, 284.

See also Tocopherols
VLE. See Vapor-liquid equilibrium
Voacangine, 261
Volatile oils
cost of manufacturing of, 261
from Latin American plants, 245–247, 252
liquid solvent extraction and, 310
sources of, 311–312
spices and, 341
Volatility, 18, 67
Volume, 2, 71

W
W3 fatty acids, 201–202, 223
Walnuts, 65, 70
Water, 3, 13–14
Wax ester oils, 146–147, 181
Waxes, 146–147, 181, 310, 315–316
Wertheim’s statistical association fluid theory, 7
Wheat germ, 82, 85
Wheat plumule, 82
Workflows, 42–43

X
Xanthophylls, 56, 193
Xylopia aromatica, 247

Z
Zeaxanthin, 84, 281

7089_Index.indd 402 10/8/07 11:48:26 AM

Similer Documents