Green solvent extraction and quality characteristics of passion fruit seed oil (Passiflora edulis Sims var. edulis)
ISSN 2588-1299
VJAS 2019; 2(4): 469-474
Vietnam Journal
of Agricultural
Sciences
Green Solvent Extraction and Quality
Characteristics of Passion Fruit Seed Oil
(Passiflora edulis Sims var. edulis)
Nguyen Thi Thu Nga, Nguyen Xuan Bac & Lai Thi Ngoc Ha
Faculty of Food Science and Technology, Vietnam National University of Agriculture,
Hanoi 131000, Vietnam.
Abstract
The extraction of oil from passion fruit seeds with acetone, ethanol,
ethyl acetate, isopropanol, and hexane was studied. The effects of the
variables, namely type of solvent, material to solvent ratio,
temperature, and extraction time, were investigated. The highest
extraction yield was 78.52%, which was obtained using ethyl acetate
with a material to solvent ratio of 1/10 at room temperature (28oC)
for 4h using a shaker. This yield was similar to that obtained when
using hexane as a solvent. Our results indicate that ethyl acetate can
replace the conventional hexane solvent in the extraction of oil from
passion fruit seeds. The high content of polyunsaturated fatty acids in
passion fruit seed oil suggests that this product has good potential for
use in the human food, cosmetic, and pharmaceutical industries.
Keywords
Oil extraction, Passiflora edulis Sims var. edulis, passion fruit seed
oil, polyunsaturated fatty acids
Introduction
The purple passion fruit (Passiflora edulis Sims var. edulis) and
the yellow passion fruit (Passiflora edulis Sims var. flavicarpa) are
two subvarieties of P. eduliks, which is the significant commercial
value variety of the family Passifloraceae (Rehm & Espig, 1984). The
purple passion fruit is mainly grown for fresh fruits and concentrated
juice processing in Vietnam. The industrial processing of passion
fruit juices produces large amounts of by-products, including seeds
and peels, that account for up to 60% of the total fruit weight (Silva
et al., 2015). While discarding passion fruit seeds may lead to an
increasing environmental problem, their high lipid content, around
30% (Oliveira et al., 2014; Silva et al., 2015), could be employed in
the food and cosmetic industries (Oliveira et al., 2013).
Received: June 9, 2019
Accepted: December 25, 2019
Correspondence to
ORCID
Lai Thi Ngoc Ha
3752
In general, the extraction of oil from the seeds can be done easily
and efficiently using organic solvents, and the efficiency mainly depend
469
Green Solvent Extraction and Quality Characteristics of Passion Fruit Seed Oil (Passiflora edulis Sims var. edulis)
on the choice of solvents (Cowan, 1999). Hexane
is the most popular solvent for oil extraction due
to its low cost and the high solubility of oils in
hexane. However, hexane is not allowed to be
used as a solvent “for all uses” in the food
industry because of environmental and public
health concerns. There are a number of solvents
that are friendly to the environment, like acetone,
ethanol, ethyl acetate, and isopropanol, because
they generate less waste than other solvents
(Oliveira et al., 2013) and can be used in the food
industry (Directive 2009/32/EC of the European
Parliament and of the Council). Besides solvents,
the material to solvent ratio as well as the
extraction temperature and time are generally
known as factors affecting oil extraction from
plant materials.
collected and transported to the laboratory on the
day of processing at the factory. The seeds were
first washed with tap water to remove the aril
around the seeds, rinsed in distilled water three
times, and then dried under sunlight to 10%
moisture content. Before extraction, the dried
seed samples were ground into a fine powder
form (from 0.5 to 1mm in diameter) with a
laboratory grinder (HR2115, Philips) and kept in
a sealed container (dark, dry, and at 4oC).
Sample extraction
The dried passion fruit seed powder (5g) was
mixed with different solvents (acetone, ethanol,
ethyl acetate, isopropanol, or hexane) in
Erlenmeyer flasks with rubber tops. The solvents
were added at different sets of seed to solvent
ratios of 1/4, 1/6, 1/8, 1/10, and 1/12. The
Erlenmeyer flasks then were placed in an orbital
incubator shaker Gyromax 727 (Amerex
Instruments, Inc., USA) with a shaking speed of
150 rounds/min. The extraction times were 0.5,
1, 2, 3, 4, 5, and 6 hours at varying temperatures
(room temperature, 40, 50, 60, and 70oC).
Afterwards, the crude extracts were transferred
to 50mL falcon conical centrifuge tubes and
centrifuged at 6,000rpm for 20 minutes with a
Hermle Z400 (Hermle, Germany) tabletop
centrifuge. The supernatants were concentrated
using a rotary evaporator R-210 Rotavapor
(Buchi, Switzerland) at the boiling point of the
solvent under vacuum pressure. The seed powder
was extracted in triplicate for each extraction
treatment.
The objectives of this work were: (i) to
investigate the effects of process variables on the
oil extraction from passion fruit seeds using a
shaker with green solvents (acetone, ethanol,
ethyl acetate, and isopropanol) in comparison
with using the conventional solvent (hexane);
and (ii) to determine the chemical and quality
characteristics of the oil obtained from the seeds
of a purple passion fruit variety commonly
grown in Vietnam. This study was the first step
in investigating the exploitation of passion seeds
as an additional dietary source of an essential
polyunsaturated fatty acid (PUFA).
Materials and Methods
Sample preparation
Purple passion fruit seeds (Passiflora edulis
Sims var. edulis) were obtained from the
Nafoods Group (Nghe An, Vietnam) in
November 2017. They were by-products of the
production of passion fruit concentrated juice.
Approximately 20kg of fresh seeds were
A single factor experiment was used to
determine the suitable extraction conditions for
passion fruit seeds. The influence of the
extraction parameters, namely the type of
solvent, material to solvent ratio, extraction
temperature, and time, on oil extraction yield
Table 1. Independent parameters involved in the extraction of oil from passion fruit seeds
Factor names
Type of solvent
Factor levels
Acetone, ethanol, ethyl acetate, isopropanol, and hexane
1/4, 1/6, 1/8, 1/10, and 1/12 (w/v)
Material to solvent ratio
Extraction temperature
Extraction time
Room temperature, 40, 50, 60, and 70 (oC)
0.5, 1, 2, 3, 4, 5, and 6 (hours)
Vietnam Journal of Agricultural Sciences
470
Nguyen Thi Thu Nga et al. (2019)
Table 2. Experimental design studying the effects of different extraction parameters on the oil yield of passion fruit seeds
Experiment
Type of solvent
Extraction parameters
Fixed parameter
1/8 g mL-1, 50oC, 3h
Acetone, ethanol, ethyl acetate,
isopropanol, and n-hexane
Material to solvent ratio
Extraction temperature
1/4, 1/6, 1/8, 1/10, and 1/12 (w/v)
Selected solvent, 50oC, 3h
Room temperature (28oC), 40, 50, 60,
and 70 (oC)
Selected solvent, material to solvent ratio, 3h
Extraction time
1, 2, 3, 4, and 5 (hours)
Selected solvent, material to solvent ratio, and
extraction temperature
from passion fruit seeds were studied (Tables 1
and 2). The oil extraction yield was calculated
using the equation:
experiments, the significant differences (P
<0.05) among means were subjected to one-way
analysis of variance (ANOVA) with Duncan’s
test using the statistical software SAS 9.3.
Oil extraction yield = 100.Oe/Os
where Oe is the oil content that was obtained
in the extraction and Os is the oil content in the
seeds.
Results and Discussion
Effects of the process variables on oil
extraction from passion fruit seeds using a
shaker
Methods
The oil content of passion fruit seeds
(g/100g) was determined by measuring weight
loss after a 6-cycle extraction with hexane in a
Soxhlet apparatus. The acidity index of the
extracted seed oil was determined by titration
using a solution of KOH 0.1N according to
EEC/TCVN 6127:2010. The peroxide value of
the extracted seed oil was obtained by titration
using a 0.01N solution of sodium thiosulfate
according to AOCS Cd8b-90. The fatty acid
profile of the extracted seed oil was determined
by gas chromatography (GC-FID) at the National
Institute for Food Control.
Table 3 shows the results obtained from the
shaker extraction of oil from Passiflora edulis
var. edulis seeds.
Solvent type had a strong effect on the oil
extraction yield. The results showed that ethanol,
hexane, and isopropanol gradually increased the
oil extraction yield from 71.1 to 72.47% but they
were not significantly different at a significance
level of 5%. The remaining solvents, acetone and
ethyl acetate, gave the highest oil extraction
efficiencies and performed equally well as
isopropanol and hexane. The only statistically
significant difference in the extraction yield of
passion fruit seeds was that ethanol was
significantly lower than both ethyl acetate and
acetone (P <0.05).
Statistical analysis
All experimental results in this study were
expressed as mean values ± standard errors (SE)
of nine measurements (n = 9). In the single factor
With different polarities (hexane is a non-polar
Table 3. Effects of the process variables on oil extraction yield from passion fruit seeds
Yield
(%)
Material/
solvent ratio
Yield
(%)
Yield
(%)
Extraction
time
Yield
(%)
Solvent
Acetone
Extraction temperature
72.98a
71.1b
1/4
1/6
63.10c
72.88b
74.51b
78.01a
79.17a
Room temperature
75.66b
76.60ab
77.00ab
77.46a
77.74a
1h
2h
3h
4h
5h
71.41c
71.62c
75.26b
78.52a
79.49a
Ethanol
40oC
50oC
60oC
70oC
Ethyl acetate
Isopropanol
Hexane
73.67a
72.47ab
72.07ab
1/8
1/10
1/12
Note: Values in the same column that do not share a common superscript are significantly different (P <0.05).
471
Green Solvent Extraction and Quality Characteristics of Passion Fruit Seed Oil (Passiflora edulis Sims var. edulis)
solvent, ethanol and isopropanol are polar
solvents, and ethyl acetate and acetone are
aprotic polar solvents), different solvents
resulted in different extraction efficiencies. The
data indicated that the aprotic polar solvents were
more suitable for the extraction of oil from purple
passion fruit seeds since ethyl acetate and
acetone had better oil extraction capacities than
ethanol. Oliveira et al. (2014) also found the
same result in that acetone was the best solvent
compared to ethanol and isopropanol in
extracting oil from passion fruit seeds.
extracting solvent was used in the extraction of
oil from passion fruit seeds and thus, this ratio
was chosen for the determination of the
extraction temperature and extraction time.
Regarding the extraction temperature, the
results indicated a significant increase in the oil
extraction yield when the temperature increased
from room temperature (28oC) to 60oC (P <0.05)
but the oil extraction efficiency did not
significantly differ between the temperatures of
60 and 70oC (P >0.05).
When performing extractions at low and
mediate temperatures, from room temperature to
50oC, the flexibility of the fatty constituents in
the materials was not strongly promoted; hence,
the extraction efficiency was around 76%. When
the temperature was raised to 60oC, the thermal
conductivity increased, which made the diffusion
coefficient of the solutes increase, consequently
increasing their solubility (Al-Farsi & Chang,
2007) and thus, accelerating the whole extraction
up to 78%. Although increasing the temperature
to 60oC resulted in a 2% increase in the oil
extraction yield, 60oC is not only closer to the
boiling point of ethyl acetate (77oC), which
might cause significant losses in the solvent,
energy consumption, and economic efficiency,
but small constituents of materials are also easily
dissolved at this temperature, leading to
difficulties in oil recovery. Therefore, room
temperature (28oC) was selected for the
extraction of oil from passion fruit seeds in the
subsequent step.
In accordance with Directive 2009/32/EC of
the European Union on April 23, 2009, both ethyl
acetate and acetone are allowed to be used as
solvents in the food industry because they
generate less waste than other solvents. Because
the boiling point of ethyl acetate is 77oC, higher
than that of acetone (56oC), ethyl acetate was
selected for the next experiment due to less
solvent loss during oil recovery.
The oil content in the extracts strongly
depended on the material to solvent ratio. There
was an increase of the passion fruit seed oil yield
with an increase of the material to solvent ratio
(w/v). The material to solvent ratio of 1:12 (w/v)
showed the highest amount of oil but was not
significantly different from the ratio of 1:10 (w/v)
(P >0.05). The opposite behavior is reported by
Oliveira et al. (2014) who found that the ratio 1:4
of passion fruit seeds to solvent was the best ratio
to extract oil from these seeds. Maybe
differences between yellow and purple passion
fruit seeds led to the differences in findings
between the results of Oliveira et al. (2014) and
our study.
The evaluation of the extraction time
showed that the extraction capacity of passion
fruit seeds increased sharply when the
extraction time was increased to 4h, but at
longer extraction times, the efficiency did not
increase significantly (P >0.05). This finding
is in agreement with the report of Oliveira et
al. (2014) who reported that the highest oil
extraction capacity value from passion fruit
seeds was obtained after 4h of extraction.
These phenomena could be explained by Fick’s
second law of diffusion, predicting that a final
equilibrium between the solute concentration
in the plant matrix and in the solvent might be
reached after a certain time.
A high material to solvent ratio could
promote an increased concentration gradient,
producing a higher chance of oil coming into
contact with the extraction solvent, resulting in
an increased diffusion rate that allows for greater
extraction of materials by the solvent (Cacace &
Mazza, 2003). These results were consistent with
the mass transfer principle. However, the active
component yields would not continue to increase
once equilibrium had been reached (Herodež et
al., 2003). An equilibrium constant trend was
observed at the material to solvent ratio of 1:10
(w/v) that indicated a sufficient amount of
Vietnam Journal of Agricultural Sciences
472
Nguyen Thi Thu Nga et al. (2019)
used as an indicator of lipid oxidation. High
peroxide values of extracted oil indicate that the
oil was exposed to oxidative processes during the
preparation of the raw material, extraction, or oil
storage. In our study, the peroxide value of the
seed oil from P. edulis var. edulis was 2.5 times
lower than peroxide value of the seed oil from P.
edulis var. flavicarpa found by Silva et al. (2015)
of 1.54 ± 0.14 meqO2kg-1 and far lower than the
value that the Codex Alimentarius Commission
established for refined and crude oils in 2008 at
15 meqO2kg-1.
Chemical and quality characteristics of
Passiflora edulis var. edulis seed oil
According to the chemical characteristics of
passion fruit seed oil (Table 4), the oil content of
Passiflora edulis var. edulis seeds was 27.28% on
a dry basis indicating that these seeds were a good
oil source when compared to soybean seeds,
which contain about 25% on a dry basis (Hammad
et al., 2012). The oil content reported in this study
was higher than the values of 18.5% for P. edulis
var. edulis seeds and 20.6% for P. edulis var.
flavicarpa seeds in Uganda found by Nyanzi et al.
(2005), and lower than the figures of 30.39% and
30.22% for yellow passion fruit seeds in Brazil
found by Malacrida & Jorge (2012) and Silva et
al. (2015), respectively. Differences in the oil
contents of P. edulis could be due to genetic,
climate, and geographical attributes.
The GC analysis of the fatty acids of the P.
edulis var. edulis seed oil showed a high content
of unsaturated fatty acids such as linoleic and
oleic (Table 5). Linoleic acid (C18:2n6), an
essential polyunsaturated omega-6 fatty acid for
humans, was the most dominant fatty acid
making up 75.7% of the total fatty acids and was
followed by oleic acid (C18:1n9) at 9%. These
data were in agreement with the results reported
by Nyanzi et al. (2005) in that linoleic and oleic
acids made up the majority of the fatty acids
found in the extracted oil of P. edulis var. edulis
seeds with the values of 74.3% for linoleic acid
and 13.6% for oleic acid.
The acidity index of the extracted oil
provides important information on the condition
of oil conservation. A high acidity index
indicates that the oil was partly oxidized or
degraded. The value found in this study (1.61 ±
0.05 mg KOHg-1) was equal with the value found
by Silva et al. (2015) and 1.5 times lower than
the quality parameter of 4.0 mg KOHg-1
according to The Codex Alimentarius
Commission (2008). This result indicates that the
studied oil can be used for food purposes as it
meets the required standard.
In comparison to the fatty acid compositions
of soybean oil and sunflower oil, two popular
vegetable oils used in the food, cosmetic, and
pharmaceutical industries (Rabasco & Gonzalez,
2000), the percentage of saturated fatty acids in
The determination of the peroxide value is
Table 4. Chemical characteristics of P. edulis var. edulis seeds oil
Component
Oil content (%)
Acidity index (mg KOH g-1)
Peroxide value (meqO2 kg-1)
Value*
27.28 ± 0.54
1.61 ± 0.05
0.62 ± 0.03
Note: * Each value is the mean ± SD of triplicate extractions and determinations.
Table 5. Fatty acid composition of P. edulis var. edulis seed oil
Fatty acids
Composition (%)
Oleic acid (C18:1n9c)
Linoleic acid (C18:2n6)
9
75.7
0.94
14
Docosahexaenoic acid (C22:6n3)
Saturated fatty acid (SFA)
Unsaturated fatty acid (UFA)
86
473
Green Solvent Extraction and Quality Characteristics of Passion Fruit Seed Oil (Passiflora edulis Sims var. edulis)
passion fruit seed oil amounted to 14%, while
the value obtained for soybean oil was slightly
higher (15.1%) and the value for sunflower oil
was a little lower (12.36%). Among the
monounsaturated fatty acids, oleic acid was the
main representative and its content was the
lowest in passion fruit seed oil (9%) and
highest in soybean oil (21.73%), while the
level of oleic in sunflower oil was 15.93%
(Zambiazi et al., 2007). Linoleic was the
dominant fatty acid among the polyunsaturated
fatty acids (PUFAs) and the linoleic acid
amount in passion fruit seed oil was higher than
the vales determined in sunflower oil and
soybean oil, which were 71% and 56%,
respectively. It can also be noted that
sunflower oil’s high PUFA content makes this
oil a good salad oil source (Sullivan, 1980),
and with the primary constituents of oleic,
linoleic, and linolenic acids, soybean oil and
sunflower oil can be employed in cosmetic
products and pharmaceutical formulations
(Rabasco & Gonzalez, 2000). Hence, the high
content of PUFAs of the studied oil indicates
this product is a good source of essential
PUFAs for human use.
References
Al-Farsi M. A. & Chang Y. L. (2007). Optimization of
phenolics and dietary fibre extraction from date seeds.
Food Chemistry. 108(3): 977-985.
Cacace J. E. & Mazza G. (2003). Mass transfer process
during extraction of phenolic compounds from milled
berries. Journal of Food Engineering. 59: 379-389.
Codex Alimentarius. Fats, oils and related products
(revised 2001). Second edition. 8.
Cowan M. M. (1999). Plant products as antimicrobial agents.
Clinical Microbiology Reviews. 12(4): 564-582.
Directive 2009/32/EC (2009). The European Parliament
and the Council of the European Union. on extraction
solvents used in the production of foodstuffs and food
ingredients. Official Journal of the European Union.
141: 3-11.
Hammad K. H. A., Zhmurko V. V. & Avksentyeva O. A.
(2012). Seed Protein and Oil Content of the Soybean
Cultivars under Different Climate Condition (Glycine
max (L.) Merr.). American-Eurasian Journal of
Agricultural and Enviromental Science. 12(5): 603-607.
Herodež Š. S., Hadolin M., Škerget M. & Knez Ž. (2003).
Solvent extraction study of antioxidants from Melissa
officinalis L. leaves. Food Chemistry. 80: 275-282.
Malacrida C. R. & Jorge N. (2012). Yellow passion fruit
seed oil (Passiflora edulis f. flavicarpa): physical and
chemical characteristics. Brazilian Archives of
Biology and Technology. 55(1): 127-134.
Nyanzi S. A., Carstensen B. & Schwack W. A. (2005). A
Comparative Study of Fatty Acid Profiles of Passiflora
Seed Oils from Uganda. Journal of American Oil
Chemists’ Society. 82(1): 41-44.
Conclusions
Oliveira R. C., Barros S. T. D. & Gimenes M. L. (2013).
The extraction of passion fruit oil with green solvents.
Journal of Food Engineering 117: 458-463.
In this study, the effects of process variables
on the solvent extraction of oil from passion fruit
seeds were investigated using a shaker. The
highest extraction yield was 78.52%, which was
obtained using ethyl acetate at the ratio of 1:10
material to solvent at room temperature (28oC)
for 4h, and was similar to the results obtained
with the conventional solvent hexane. Our results
indicate that passion fruit seed oil extracted by
ethyl acetate has a high content of PUFAs
(around 77%) and thus, has good potential for use
in the human food, cosmetic, and pharmaceutical
industries.
Oliveira R. C., Guedes T. A., Gimenes M. L. & Barros S.
T. D. (2014). Effect of process variables on the oil
extraction from passion fruit seeds by conventional
and non-conventional techniques, Acta Scientiarum
Technol. 36: 87-91.
Rabasco A. A. M. & González R. M. L. (2000). Lipids in
pharmaceutical and cosmetic preparations. Grasas
Aceites. 51: 74-96.
Rehm S. & Espig G. (1984). The Cultivated Plants of the
Tropics and Subtropics, Eugen Ulhmer Publishers,
Stuttgart, Germany. 185-186 (in German).
Silva R. M., Placido G. R., Silva M. A. P., Castro C. F. S.,
Lima M. S.
& Caliari M. (2015). Chemical
characterization of passion fruit (Passiflora edulis f.
flavicarpa) seeds, African Journal of Biotechnology.
14: 1230-1233.
Acknowledgements
Sullivan F. E. (1980). Sunflower oil processing from crude
to salad oil, Journal of the American Oil Chemists'
Society. 57: 845-847.
The authors would like to acknowledge
Vietnam National University of Agriculture
for providing financial support under the
Research Grant Scheme (Grant agreement
T2017-08-55).
Zambiazi R. C., Przybylski R., Zambiazi M. W. &
Mendonça C. B. (2007). Fatty acid composition of
vegetable oils and fats. Boletim Centro de Pesquisa de
Processamento de Alimentos. 25: 111-120.
Vietnam Journal of Agricultural Sciences
474
6 trang
18080
Free
Bạn đang xem tài liệu "Green solvent extraction and quality characteristics of passion fruit seed oil (Passiflora edulis Sims var. edulis)", để tải tài liệu gốc về máy hãy click vào nút Download ở trên
File đính kèm:
- green_solvent_extraction_and_quality_characteristics_of_pass.pdf
