U.S. patent application number 13/832499 was filed with the patent office on 2013-09-26 for extractions of fixed oil and thymoquinone rich fractions (tqrf).
This patent application is currently assigned to UNIVERSITI PUTRA MALAYSIA. The applicant listed for this patent is UNIVERSITI PUTRA MALAYSIA. Invention is credited to Nurzatul Efa Adnan, Ghanya AL-NAQEEB, Wei Chan, Maznah ISMAIL.
Application Number | 20130253210 13/832499 |
Document ID | / |
Family ID | 42233419 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130253210 |
Kind Code |
A1 |
ISMAIL; Maznah ; et
al. |
September 26, 2013 |
Extractions of Fixed Oil and Thymoquinone Rich Fractions (TQRF)
Abstract
The present invention reported that SFE is suitable for Nigella
sativa seeds oil extraction and fractionation. TQRF that were
produced through SFE extractions (600 bars/40.degree. C.) and
fractionations (100-200 bars/40-60.degree. C.) possessed high level
of TQ and antioxidant activity. SFE fractionation efficiently
concentrates the TQ content and antioxidant activity of Nigella
sativa seeds oil in short time and low cost manners without using
any hazardous organic solvents.
Inventors: |
ISMAIL; Maznah; (Selangor
Darul Ehsan, MY) ; AL-NAQEEB; Ghanya; (Selangor Darul
Ehsan, MY) ; Chan; Wei; (Selangor Darul Ehsan,
MY) ; Adnan; Nurzatul Efa; (Selangor Darul Ehsan,
MY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UNIVERSITI PUTRA MALAYSIA |
Selangor Darul Ehsan |
|
MY |
|
|
Assignee: |
UNIVERSITI PUTRA MALAYSIA
Selangor Darul Ehsan
MY
|
Family ID: |
42233419 |
Appl. No.: |
13/832499 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12739748 |
Apr 26, 2010 |
8501250 |
|
|
PCT/MY2009/000115 |
Aug 7, 2009 |
|
|
|
13832499 |
|
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Current U.S.
Class: |
554/11 ;
554/9 |
Current CPC
Class: |
A61P 31/04 20180101;
A61P 35/00 20180101; A61P 29/00 20180101; A61P 39/06 20180101; B01D
11/0288 20130101; A61P 3/10 20180101; C11B 3/006 20130101; B01D
11/0203 20130101; A61P 37/04 20180101; C11B 1/104 20130101; A61P
9/12 20180101; A61P 37/02 20180101; A23L 33/105 20160801; B01D
11/0203 20130101; B01D 11/0288 20130101 |
Class at
Publication: |
554/11 ;
554/9 |
International
Class: |
C11B 1/10 20060101
C11B001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 4, 2008 |
MY |
PI 20084925 |
Claims
1. A supercritical fluid extraction process for extracting a fixed
oil from Nigella sativa seeds, the process comprising the step of
extracting crude oil from Nigella sativa seeds at a pressure of
between 300 to 600 bars and at temperature of between 31 to
80.degree. C.
2. The process as claimed in claim 1, wherein the process comprises
a carbon dioxide feed of between 25 to 30 g/min.
3. The process as claimed in claim 1, wherein the process is
conducted for a period of between 2 to 3 hours.
4. The process as claimed in claim 1, wherein the supercritical
fluid is supercritical carbon dioxide.
5. The process as claimed in claim 1, wherein the process is
conducted with a sample size of 100 g of cleaned, dried and ground
Nigella sativa seeds.
6. The process as claimed in claim 1, wherein the exhaustive
extraction of TQ occurs in the first hour of extraction.
7-25. (canceled)
Description
[0001] This application is a national stage of PCT/MY2009/000115,
filed Aug. 7, 2009, which claims priority under 35 U.S.C. .sctn.119
to PI 20084925, filed Dec. 4, 2008, the entire disclosure of which
is herein expressly incorporated by reference.
FIELD OF INVENTION
[0002] The present invention is generally referred to extractions
of fixed oil and thymoquinone rich fractions (TQRF).
BACKGROUND OF INVENTION
[0003] Nigella sativa L. belongs to the family of Ranuculaceae,
which is known as food flavouring agents, food preservatives as
well as health-promoting ingredients since few thousands years ago.
Generally, Nigella sativa seeds contain more than 30% of fixed oil
and 0.40% to 0.45% of volatile oil. Nigella sativa oil is
considered as one of the excellent functional edible oil due to its
advantage role in human nutrition as well as diseases prevention
and treatment.
[0004] Thymoquionone (TQ) is the major bioactive component (18.4%
to 24%) in Nigella sativa volatile oil. Many pharmacological
researches reported that Nigella sativa oil and its bioactive
compound, TQ possesses multiple health-beneficial activities, which
include anti-tumor, anti-inflammatory, anti-bacterial,
anti-diabetic, anti-hypertensive, hyperglycemic, anti-oxidatative
and immuno-modulation activities.
[0005] Due to its multiple health benefits, extraction of TQ from
Nigella sativa seeds is of prime importance and thus has received
continuous attention from researchers and nutraceutical industry
worldwide recently. However, the present methods (solvent
extractions and hydro distillation) that are used in the oil
extraction of Nigella sativa seeds are not only time-consuming,
costly and environmental hazardous, it also imposes a threat to
consumers' health if the organic solvents are not completely
removed from the extractives. In this scenario, supercritical
carbon dioxide fluid extraction (SFE) seems to be a better
alternative for Nigella sativa seeds extraction. Advantageously,
SFE offers the usage of non-toxic, non-explosive, environmental
friendly, cost effective, time saving and selectivity-adjustable
solvent (supercritical carbon dioxide fluid) in the extraction
process. Further more, it also enables the oil extraction to be
carried out under low temperature and oxygen-free condition. This
feature is very crucial in the extraction of bioactive compounds
that are highly susceptible to oxidative degradation, for instance
TQ. On the other hand, simultaneous fractionation by using SFE
enables the concentration of targeted bioactive compound such as TQ
to be conducted in a solvent-free as well as time and cost saving
manner.
[0006] The objective of this invention is to develop an extraction
procedure to obtain Nigella sativa seeds oil and fractions that are
high in bioactive compounds (such as TQ) and anti-oxidative
activity through SFE extraction and fractionation.
SUMMARY OF INVENTION
[0007] Accordingly, there is provided a supercritical fluid
extraction process for extracting a fixed oil from Nigella sativa
seeds, the process includes the step of extracting Nigella sativa
seeds crude oil at a pressure of between 300 to 600 bars and at
temperature of between 31 to 80.degree. C.
[0008] Also provided is supercritical fluid extraction process
having a carbon dioxide feed of between 25 to 30 g/min for
extracting Thymoquinone Rich Fractions (TQRF) from Nigella sativa
seeds, the process includes the steps of (a) extracting Nigella
sativa seeds crude oil at a pressure of between 300 to 600 bars and
at temperature of between 31 to 80.degree. C. and (b) fractionating
Nigella sativa seeds crude oil obtained in step (a) at a pressure
of 100 to 300 bars and at temperatures of 31 to 80.degree. C.
[0009] Further there is also provided a supercritical fluid
extraction process having a carbon dioxide feed of between 25 to 30
g/min for simultaneously extracting a fixed oil and Thymoquinone
Rich Fractions (TQRF) from Nigella sativa seeds, the process
includes the steps of (a) extracting Nigella sativa seeds crude oil
at a pressure of between 300 to 600 bars and at temperature of
between 31 to 80.degree. C. and (b) fractionating Nigella sativa
seeds crude oil obtained in step (a) at a pressure of 100 to 300
bars and at temperatures of 31 to 80.degree. C.
[0010] The present invention consists of several novel features and
a combination of parts hereinafter fully described and illustrated
in the accompanying description and drawings, it being understood
that various changes in the details may be made without departing
from the scope of the invention or sacrificing any of the
advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings constitute part of this specification and
include an exemplary or preferred embodiment of the invention,
which may be embodied in various forms. It should be understood,
however, the disclosed preferred embodiments are merely exemplary
of the invention. Therefore, the drawings attached herein are not
to be interpreted as limiting, but merely as the basis for the
claims and for teaching one skilled in the art of the
invention.
[0012] FIG. 1 shows the yield of different Nigella sativa seeds oil
fractions (n=2);
[0013] FIG. 2 shows the TQ concentration of different Nigella
sativa seeds oil fractions (n=2);
[0014] FIG. 3 shows the DPPH radical scavenging activity of
different Nigella sativa seeds oil fractions (n=2); and
[0015] FIG. 4 shows the galvonoxyl scavenging activity of different
Nigella sativa seeds oil fractions (n=2).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present invention is generally referred to extractions
of fixed oil and thymoquinone rich fractions (TQRF). Hereinafter,
this specification will describe the present invention according to
the preferred embodiments of the present invention. However, it is
to be understood that limiting the description to the preferred
embodiments of the invention is merely to facilitate discussion of
the present invention and it is envisioned that those skilled in
the art may devise various modifications and equivalents without
departing from the scope of the appended claims.
[0017] The present invention provides a SFE extraction procedure
that allows the total oil extraction of Nigella sativa seeds and TQ
concentration of Nigella sativa oil fraction to be carried out
simultaneously. Through the present invention, high antioxidative
TQRF from Nigella sativa seeds could be obtained in a shorter time
and lower cost manner without using any further purification
processes that involved usage of hazardous organic solvents as well
as expensive equipments. Besides producing TQRF, the present
invention also simultaneously produces large amount of Nigella
sativa seeds fixed oil (NSO) that might possess other economical
values. NSO could be the major ingredient in lower range of Nigella
sativa nutraceutical and cosmoceutical products such as functional
cooking oil, facial cream and so on. Thus, the present invention
also contributes to the wastage reduction and functionality
diversification of Nigella sativa seeds oil.
[0018] Generally, the present invention provides extractions of
fixed oil and TQRF from Nigella sativa seeds including the steps of
extracting Nigella sativa seeds crude oil at a pressure of between
300 to 600 bars and at temperature of between 31 to 80.degree. C.
and fractionating Nigella sativa seeds crude oil obtained in step
(a) at a pressure of 100 to 300 bars and at temperatures of 31 to
80.degree. C.
[0019] The extractions can be independent i.e. the fixed oil and
TQRF can be extracted separately or simultaneous extractions.
[0020] In the preferred embodiments of the present invention, the
supercritical fluid is supercritical carbon dioxide and the
extractions are based on sample size of 100 g of cleaned, dried and
ground Nigella sativa seeds.
[0021] Reference will be made to following examples and these
examples are intended to be illustrative and not limiting.
Selection of SFE Parameters for Fractionation
[0022] a. Sample Preparation
[0023] Nigella sativa seeds were cleaned and dried in oven at
40.degree. C. until constant weight attained. Then, 100 g of the
seeds were ground into powder by using electrical grinder (Waring
Blender) for 1 min. This procedure should be performed just before
the SFE extraction was initiated.
b. SFE Extraction
[0024] Nigella sativa seeds were extracted by using Supercritical
Carbon Dioxide Extractor (Thar 1000 F) at 4 different extraction
parameters (pressure (bars)/temperature (.degree. C.) as follows:
400 bars/40; 600/40; 600/60; 600/80). Briefly, one hundred grams of
ground Nigella sativa seed was placed into a 1 liter extraction
vessel. After the extraction vessel was tightly sealed, the desired
extraction temperature was set. Pressure within the extraction
vessel was built up with a constant carbon dioxide flow rate (30
g/min) and regulated by automated back pressure regulator. The SFE
extraction was initiated after the desirable temperature and
pressure were achieved. The entire extraction process lasted for 3
hours and oil samples were collected from collection vessel after
each interval of one hour. The total oil yield from the extraction
was calculated through the accumulation of interval yields.
c. Determination of TQ Content In Nigella sativa SFE Oils
[0025] TQ content in Nigella sativa oils was determined by using
analytical HPLC (Agilent 1100), completed with C.sub.18
reversed-phase column (Zorbax SB-C18). Mobile phase was consisted
of water, methanol (Fisher Scientific) and iso-propanol (Fisher
Scientific) at the ratio of 50:45:5 (v/v), respectively. Flow rate
of the mobile phase was set at 1.5 ml min.sup.-1. Nigella sativa
oils were initially dissolved in isopropanol and filtered through
0.45 .mu.m Millipore filter prior to the injection (20 .mu.l) into
HPLC system. Thymoquinone contents of Nigella sativa SFE oils were
determined through Thymoquinone standard (Sigma) curve and
expressed in mg TQ/g oil.
d. Results
TABLE-US-00001 TABLE 1 Oil yield of Nigella sativa seeds oils
extracted by SFE (n = 3) Oil Yield At Each Hour of SFE SFE
Extraction (%, w/w); Accumulated Parameters 1.sup.st hour 2.sup.nd
hour 3.sup.rd hour yield (%, w/w) 400 bars/ -- -- -- 19.32 .sup.a
.+-. 0.81 40.degree. C. 600 bars/ 18.81 .+-. 0.22 5.08 .+-. 0.48
4.02 .+-. 0.70 27.92 .sup.b .+-. 1.27 40.degree. C. 600 bars/ 19.24
.+-. 0.65 5.78 .+-. 0.47 4.55 .+-. 0.37 29.47 .sup.b .+-. 1.26
60.degree. C. 600 bars/ 24.44 .+-. 0.38 7.34 .+-. 0.95 5.08 .+-.
0.09 36.87 .sup.c .+-. 0.81 80.degree. C. .sup.a-c Different
alphabets within same column indicated significant difference (P
< 0.05).
TABLE-US-00002 TABLE 2 TQ content of Nigella sativa seeds oils
extracted by SFE (n = 3) Accumulated TQ Accumulated TQ SFE TQ
content in the oil At Each Hour of SFE content in the content in
total Parameters Extraction (g TQ/100 g oil) oil (mg TQ/ oil yield
(g TQ/ (bars/.degree. C.) 1.sup.st hour 2.sup.nd hour 3.sup.rd hour
g oil) 100 g seeds) 600/40 2.77 .+-. 0.20 0.93 .+-. 0.18 0.49 .+-.
0.09 21.01 .sup.a 0.587 600/60 2.49 .+-. 0.38 1.08 .+-. 0.53 0.79
.+-. 0.64 19.59 .sup.a 0.577 600/80 2.10 .+-. 0.16 0.70 .+-. 0.10
0.52 .+-. 0.04 16.02 .sup.b 0.590 .sup.a-b Different alphabets
within same column indicated significant difference (P <
0.05).
[0026] Tables 1 and 2 show the yield and TQ content of Nigella
sativa seeds oils extracted by SFE, respectively. Result indicates
that a rise in extraction pressure from 400 bars to 600 bars under
isothermal condition (40.degree. C.) significantly increases the
yield of Nigella sativa oil (P<0.05). Besides, results also
indicate that a rise in SFE extraction temperature at constant
pressure of 600 bars significantly increases the yield obtained but
reduced the TQ content in the oil (P<0.05). SFE extraction at
600 bars coupled with temperature ranging from 40-80.degree. C.
efficiently extracted most of the oil and TQ (>50% from the
total extractable matter) from Nigella sativa seeds in the first
hour of extraction. However, a descending fall in oil yield and TQ
content was observed in the subsequent two hours of extraction.
Through this experiment, 600 bars/40.degree. C. was chosen as the
SFE parameters for further fractionation due to its high TQ content
and low energy (heat) requirement.
Production of High Antioxidative TQRF from Nigella sativa Seeds
Through SFE Fractionation a. Sample Preparation
[0027] Nigella sativa seeds were cleaned and dried in oven at
40.degree. C. until constant weight attained. Then, 100 g of the
seeds were ground into powder by using electrical grinder (Waring
Blender) for 1 min. This procedure should be performed just before
the SFE extraction was initiated.
b. SFE Extraction and Fractionation
[0028] Nigella sativa seeds were extracted (600 bars/40.degree. C.)
and fractionated by using Supercritical Carbon Dioxide Extractor
(Thar 1000 F) at 9 different fractionation parameters (pressure
(bars)/temperature (.degree. C.)) as followed: 300 bars/40.degree.
C., 300 bars/60.degree. C., 200 bars/40.degree. C., 200
bars/60.degree. C., 100 bars/40.degree. C., 100 bars/60.degree. C.
Briefly, one hundred grams of ground Nigella sativa seed was placed
into a 1 liter extraction vessel. After the extraction vessel was
tightly sealed, the extraction temperature was set at 40.degree. C.
Pressure within the extraction vessel was built up with a constant
carbon dioxide flow rate (25 g/min) and regulated by automated back
pressure regulator. The SFE fractionation was initiated after the
extraction vessel reached 600 bars and 40.degree. C. Fractionation
of Nigella sativa oil was carried out in a first collection vessel
1 by regulating the inner pressure and temperature of the vessel
according to 6 different designed fractionation parameters:
(pressure (bars)/temperature (.degree. C.): 300 bars/40.degree. C.,
300 bars/60.degree. C., 200 bars/40.degree. C., 200 bars/60.degree.
C., 100 bars/40.degree. C., 100 bars/60.degree. C.). At the same
time, the condition of second collection vessel was set at
atmospheric pressure (1 bar) and room temperature (25.degree. C.)
in order to collect the all the extractives from fractionation in
the first vessel. The entire extraction and fractionation processes
lasted for 2.5 hours. After the extraction was completed, the
extraction vessel and the first collection vessel were
depressurized and the fractions were collected from the first
collection vessel and the second collection vessel, respectively.
The yield of Nigella sativa fractions in first collection vessel
and the second collection vessel were calculated finally. SFE
unfractionated and petroleum ether extracted (Soxhlet, AOAC method)
Nigella sativa oils were used as the subjects for comparison in
this example.
c. Solvent Extraction by Using Soxhlet Method
[0029] Solvent extraction by using soxhlet method (AOAC method) was
done and the solvent used is petroleum ether. First, 10 grams of
ground Nigella sativa seeds were weighed and transferred into an
extraction thimble. Then, the thimble was transferred into a
soxhlet extractor (Witeg, Germany) and a weighed flask was
attached. 200 ml of petroleum ether was added into the flask. The
apparatus was connected to the condenser and water tap was turned
on. The extraction was done for 8 hours on an electro thermal
extraction unit. After 8 hours, the flask containing the petroleum
ether was removed. The petroleum ether was evaporated under reduced
pressure. The flask then was transferred into a vacuum oven for 1
hour to dry the extract. Finally, the flask was cooled down in a
dessicator and the yield of the fractions was calculated.
d. Determination of TQ Content In Nigella sativa SFE Fractions
[0030] TQ contents in Nigella sativa fractions were determined by
using analytical HPLC (Agilent 1100), which was completed with
O.sub.18 reversed-phase column (Zorbax SB-C18). Mobile phase was
consisted of water, methanol (Fisher Scientific) and iso-propanol
(Fisher Scientific) at the ratio of 50:45:5 (v/v), respectively.
Flow rate of the mobile phase was set at 1.5 ml min.sup.-1. Nigella
sativa fractions were initially dissolved in isopropanol and
filtered through 0.45 .mu.m Millipore filter prior to the injection
(20 .mu.l) into HPLC system. Thymoquinone contents of Nigella
sativa SFE fractions were determined through Thymoquinone standard
(Sigma) curve and expressed in mg TQ/g fraction.
e. DPPH Radical Scavenging Activity of Nigella sativa SFE
Fractions
[0031] DPPH radical scavenging activity of Nigella sativa SFE
fractions was measured. .alpha.-tocopherol was used as the standard
lipophilic antioxidant in this test. In brief, 0.1 ml of toluenic
sample solution at different concentrations was added with 0.39 ml
of fresh toluenic DPPH solution (0.1 mM). Then, the mixture was
shaken vigorously and left in darkness for 60 minutes. Finally, the
absorbance of the mixture was measured against pure toluene (blank)
at 515 nm by using a UV-Visible spectrophotometer (Pharmaspec
uv-1700, Shimadzu). DPPH scavenging activity of Nigella sativa SFE
fractions were determined through .alpha.-tocopherol standard curve
and expressed in mg .alpha.-tocopherol equivalent (Teq)/g
sample.
f. Galvinoxyl Radical Scavenging Activity of Nigella sativa SFE
Fractions
[0032] Galvinoxyl radical scavenging activity of Nigella sativa SFE
fractions was measured. .alpha.-tocopherol was used as the standard
lipophilic antioxidant in this test. In brief, 20 mg of oil sample
(in 200 .mu.l of toluene) was allowed to react with 200 .mu.l of a
toluenic solution of galvinoxyl (0.125 mM) for 60 minutes.
Subsequently, the antiradical activity was of the samples was
measured at room temperature by using ESR (JEOL, Japan) at the
following conditions: center field=336.374.+-.5 mT; sweep time=1
minute; microwave power=4 mW; modulation frequency=100 kHz;
modulation width=0.08 mT; amplitude=60 and time constant=0.1
second. Galvinoxyl radical scavenging activity of Nigella sativa
SFE fractions were determined through .alpha.-tocopherol standard
curve and expressed in mg .alpha.-tocopherol equivalent (Teq)/g
sample
g. Results
[0033] The results of this test are illustrated in the accompanying
figures. FIG. 1 shows yield of different Nigella sativa seeds oil
fractions. Result indicates that Soxhlet extraction yielded higher
percentage of oil from Nigella sativa seeds as compared to all SFE
extractions (P<0.05). Besides, result also indicates that a
reduction in fractionation pressure would decrease (P<0.05) the
fraction yield obtained in the second collection vessel. whereas
variance in fractionation temperature did not alter the yield of
the fractions in most of the cases (P>0.05).
[0034] FIG. 2 shows TQ concentration of different Nigella sativa
seeds oil fractions. Result indicates that fractionation at 100
bars/40.degree. C. efficiently increased the TQ content in Nigella
sativa oil by approximately 10 folds as compared to unfractionated
and Soxhlet samples (P<0.05). On the other hand, the content of
TQ in 100 bars/40.degree. C. fraction (.about.6.5% w/w of oil) was
approximately 100 folds higher than TQ content in Nigella sativa
oil (0.05% w/w of oil) that was reported in prior art.
[0035] FIGS. 3 and 4 show DPPH and galvinoxyl radical scavenging
activities of different Nigella sativa seeds oil fractions. Result
indicates that fractionation at 100 bars/40.degree. C. and 100
bars/60.degree. C. greatly improved the antiradical activity of
Nigella sativa oil towards DPPH and galvinoxyl radicals as compared
to unfractionated and Soxhlet samples (P<0.05). In conclusion,
fractionation at 100 bars/40.degree. C. was found to be the best
SFE fractionation parameters in producing high antioxidative TQRF
due to its high content of TQ and great improvement in antioxidant
activity.
[0036] As shown in the FIGS., the manipulation of various
parameters such as pressure and temperature enables the
optimization of the yield. For an example, a rise of extraction
pressure from 400 bars to 600 bars in isothermal condition
(40.degree. C.) increases the oil yield from 19.32% to 27.919%. On
the other hand, a rise of extraction temperature from 40 to
80.degree. C. in isobaric condition (600 bars) increases the oil
yield from 27.919% to 36.87%. A decrease of extraction temperature
from 80 to 40.degree. C. in isobaric condition (600 bars) increases
the TQ content in the oil from 0.08% to 0.2% (w/w). Extraction
pressure at 600 bars coupled with extraction temperature at
40.degree. C. is the optimum SFE parameters selected for further
fractionation in order to produce oil and TQRF from Nigella sativa
seeds simultaneously.
[0037] The carbon dioxide feed is between 25 to 30 g/min and the
extraction duration is between 2.5 to 3 hours after the extraction
vessel reached the extraction pressure of 400 to 600 bars and the
extraction temperature of 40 to 80.degree. C.
[0038] It is noted that the SFE is suitable for Nigella sativa
seeds oil extraction, wherein extraction pressure ranges from 400
to 600 bars coupled with extraction temperature ranging from 40 to
80.degree. C. that result in oil yield ranging from 19.32% to
36.87% (w/w).
[0039] Extraction pressure at 600 bars coupled with extraction
temperature at 80.degree. C. results in highest oil yield (36.87%).
At the same time, extraction pressure at 600 bars coupled with
extraction temperature at 40.degree. C. results in highest TQ
content in the oil (0.2%).
[0040] At isobaric (600 bars) SFE extraction at extraction
temperature ranging from 40 to 80.degree. C. efficiently extracted
most of the oil and TQ (>50% from the total extractable matter)
from Nigella sativa seeds in the first hour of extraction.
[0041] The process provides oil yield ranging from 3.84 to 36.01%
TQ content ranging from 5.7 to 64.5 mg of TQ/g oil. It is noted
that a descending fall in oil yield and TQ content was observed in
the second and third hour of extraction.
[0042] Soxhlet Nigella sativa seeds oil as shown in FIGS. 1 to 4 is
obtained through Soxhlet extraction by using petroleum ether
according to AOAC standard. It is noted that Soxhlet extraction
yields higher than all SFE extractions and fractionations. Soxhlet
extraction yields lower TQ content than all SFE extractions and
fractionations.
[0043] Fractionation of Nigella sativa seeds oil yields higher TQ
content than Soxhlet (4.3 to 58.8 mg TQ/g oil higher) and
unfractionated (2.4 to 56.9 mg TQ/g oil higher) Nigella sativa seed
oil.
[0044] Unfractionated and Soxhlet Nigella sativa seeds oils are
produced for comparison purpose. Fractionations of Nigella sativa
seed oil at pressures of 100 to 300 bars and at temperatures of 40
to 60.degree. C. by using supercritical fluid extraction reduce the
total oil yield obtained ranging from 3.8% to 6.1% as compared to
unfractionated oil.
[0045] An increase of fractionation temperature from 40 to
60.degree. C. in isobaric condition (100, 200 and 300 bars,
respectively) increases the oil yield in a first collection vessel
but decrease the oil yield in a second collection vessel,
correspondently. On the other hand, an increase of fractionation
temperature from 100 to 300 bars in isothermal condition (40 and
60.degree. C., respectively) decrease the oil yield in a first
collection vessel but increase the oil yield in a second collection
vessel, correspondently.
[0046] It is noted that each gram of Nigella sativa seeds oils or
fractions provides antioxidant activity which is similar to 40.96
to 73.68 mg .alpha.-tocopherol through DPPH radical scavenging
activity test. Similarly, each gram of Nigella sativa oils or
fractions provides antioxidant activity, which is similar to 12.26
to 73.44 mg .alpha.-tocopherol through galvinoxyl radical
scavenging activity test.
[0047] Nigella sativa seeds fractions produced at an extraction
pressure of 600 bars and an extraction temperature of 40.degree. C.
followed by a fractionation pressure of 100 to 200 bars and an
fractionation temperature of 40 to 60.degree. C. exhibit better
antioxidant activities than Soxhlet and unfractionated oils (2.4 to
56.9 mg TQ/g oil higher) through DPPH and galvinoxyl radical
scavenging activity tests.
[0048] It is noted that the TQRF obtained from the extractions of
Nigella sativa seeds oil possesses higher TQ content and
antioxidant activity than SFE-unfractionated Nigella Sativa seeds
oil and conventional solvent (petroleum ether) extracted oil. This
is because other antioxidative compounds such as
.alpha.-tocopherol, tocotrienol and phytosterols and so on might
also contribute to the antioxidant activities of TQRF.
[0049] It must also be appreciated that the process as described
above can be used for concentrating other volatile bioactive
compounds.
* * * * *