Food Chemistry 125 (2011) 262–267
Contents lists available at ScienceDirect
Food Chemistry
journal homepage: www.elsevier.com/locate/foodchem
Analytical Methods
Extraction of b-carotenes from palm oil mesocarp using sub-critical R134a
A.N. Mustapa a, Z.A. Manan b,⇑, C.Y. Mohd Azizi b, W.B. Setianto c, A.K. Mohd Omar c
a
Faculty of Chemical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
Process Systems Engineering Centre (PROSPECT), Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia
c
Environmental Technology, Industrial Technology, Universiti Sains Malaysia, Minden 11700, Penang, Malaysia
b
a r t i c l e
i n f o
Article history:
Received 18 May 2010
Received in revised form 8 August 2010
Accepted 19 August 2010
Keywords:
b-Carotene
Palm oil
Palm mesocarp
Sub-critical R134a
Supercritical fluid extraction
a b s t r a c t
Sub-critical extraction of palm oil from palm mesocarp using R134a solvent was conducted via the
dynamic mode to investigate the ability of R134a to extract b-carotene. The yield of palm oil and the solubility of b-carotene were investigated at 40, 60 and 80 °C and pressure range from 45–100 bar. The
extracted oil was analysed for b-carotene content using UV–Vis spectrophotometry. The results showed
that palm oil yield increased with pressure and temperature. The maximum solubility of b-carotene was
obtained at 100 bar and 60 °C while the lowest solubility occurred at 80 bar and 40 °C. The higher concentration of extracted b-carotene ranging from 330–780 ppm as compared to that achieved through
conventional palm oil processing indicates that extraction of b-carotene using R134a is viable.
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
Palm oil is well-known to contain a high amount of carotenoids.
Typical crude palm oil contains 500–700 ppm carotenes, which
contribute to palm oil stability and nutritional value. Conventional
processing of palm oil leaves about 3–7% residual oil in the fruit fibre (França & Meireles, 2000; Lau, Choo, Ma, & Chuah, 2008; Nik
Norulaini et al., 2008) and a high content of carotenoids in the
pressed palm fibres. Residual fibres from palm oil production contain between 4000 and 6000 ppm of carotenoids, about six times
higher than that found in crushed palm oil (Franca & Meireless,
1997, 2000). Until now, palm oil fibre residues that are rich in valuable carotenoids are treated as a waste product, which is destined
to be burnt together with empty fruit bunches (Birtigh, Johannes,
Brunner, & Nair, 1995) or transported to the plantation for field
mulching (Lau et al., 2008). Effective recovery of the carotenes
would therefore give a significant advantage to the palm oil
industry.
Supercritical fluid extraction (SFE) technology has become an
increasingly popular method for the recovery of food ingredients
and products over the last 20 years, due to its unique advantages,
including low temperature use, selective extraction, simpler and
cleaner (solvent-free) product recovery. SFE is also an environmentally benign technology since the process typically generates no
waste. Supercritical fluid exhibits high density like liquids, which
contributes to greater potential for solubilisation of materials,
⇑ Corresponding author. Tel.: +60 7 5535609; fax: +60 7 5581463.
E-mail address: [email protected] (Z.A. Manan).
0308-8146/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.foodchem.2010.08.042
and low viscosity similar to gases, which enables its penetration
into the solid.
Extraction of palm oil from its mesocarp using supercritical
fluid technology has been considered a promising way to recover
carotenes and prevent their high losses during palm oil milling.
Application of SFE technology for crude palm oil extraction, and
for the recovery of carotenes from palm mesocarp is expected to
have a great future outlook (Bharath, 2003) was and is seen to have
great potential for replacing the conventional screw-press extraction, clarification and vacuum drying processes (Lau, Choo, Ma, &
Chuah, 2006). Therefore, the extraction of palm oil using supercritical extraction technology is set to become more popular in the
next 10 years.
Various studies aimed to investigate the potential of some marker compounds to be extracted using supercritical solvents, such as
carbon dioxide (Cygnarowicz, Maxwell, & Seider, 1990; Franca &
Meireless, 1997; Lau et al., 2008; Markom, Singh, & Hasan, 2001;
Nik Norulaini et al., 2008; Puah, Choo, Ma, & Chuah, 2005; Saldaña,
Temelli, Guigard, Tomberli, & Gray, 2010; Sovová, Stateva, &
Galushko, 2001; Škerget, Knez, & Habulin, 1995), ethane (Mendes,
Nobre, Coelho, & Palavra, 1999) and nitrous oxide (Sakaki, 1992;
Subra, Castellani, Ksibi, & Garrabos, 1997). Hansen, Harvey, Coelho,
Palavra, and Bruno (2001) reported the solubility of carotene in
halocarbon (R134a).
Carbon dioxide (CO2) has been the most popular supercritical
solvent, due to its non-toxic, non-hazardous and non-flammable
properties, but typically requires pressure of up to 500 bar for satisfactory extraction of food products. In view of the economic and
environmental needs, it is desirable to explore alternative SFE
263
A.N. Mustapa et al. / Food Chemistry 125 (2011) 262–267
solvents that enable operation at less intense conditions (Catchpole & Proells, 2001; Wood & Cooper, 2003), thereby allowing
designers to exploit the typical SFE benefits at more reasonable
costs (Perrut, 2000).
R134a (1,1,1,2-tetrafluoroethane) is non-toxic, non-reactive,
non-flammable, and non-ozone depleting. It also has a high volatility and a boiling point at atmospheric pressure of 26.2 °C, which
means that it leaves negligible solvent residues in the products.
The use of R134a as the extraction solvent at sub-critical conditions
can address the shortcomings of supercritical CO2 processes (Corr,
2002). Sub-critical fluid, which is also known as a high-pressure liquid, exhibits similar behaviour to, and can be exploited in the same
manner as, supercritical fluids (Brunner, 1994; Brunner, 2005).
To-date, only Mustapa, Manan, Mohd Azizi, Nik Norulaini, and
Mohd Omar (2009) have studied the use of sub-critical R134a as
an alternative to CO2 solvent for the recovery of palm oil. They performed the extraction of palm oil from palm mesocarp, using
R134a at sub-critical conditions. The extraction of palm oil was
found to increase with temperature and peaked at a maximum of
100 bar and 80 °C. Mustapa et al. (2009) also reported that the
extraction of palm oil using R134a has great potential for application in the palm oil industry. The objective of this study is to investigate the potential of using R134a to recover valuable minor
components by determining the yield of palm oil extracted from
palm mesocarp and the solubility trend of b-carotene in R134a
over the range of temperatures and pressures studied.
2. Methodology
2.1. Materials and sample preparation
Fresh palm fruits were provided by MALPOM Industries Sdn.
Bhd palm oil mill in Nibong Tebal, Penang, Malaysia. The fresh
fruits were put in vacuum plastic bags and stored at 20 °C. Prior
to extraction, a bag of the sample was randomly selected and was
left at room temperature for about 30 min. Commercial liquefied
R134a gas (purity 99.7%) was supplied in a gas cylinder by Malaysia Oxygen (MOX), Penang. The mesocarp of fresh palm fruits was
peeled, sliced and chopped to reduce the sample size using a Kiwi
cutter. Samples of chopped mesocarp were oven-dried to reduce its
moisture content to a range of about 5–6%. The sample was named
as Uncooked-Chopped (UC) sample. Mustapa et al. (2009) reported
that the UC sample palm fruits resulted in higher oil yield than
cooked fruits. They also reported that the chopped samples gave
higher extraction rate as compared to sliced samples. Lau et al.
(2006) peeled off the palm mesocarp and dried in the oven at
60 °C until a constant weight was obtained. Prior to the extraction
the dried mesocarp was ground into pieces of 1–3 mm length.
2.2. Sub-critical R134a extraction
The dynamic extraction is a superior SFE method when the solid
sample has a high oil concentration (De Castro, Valcárcel, & Tena,
1994). Fresh liquid solvent at ambient temperature is charged
and compressed to the desired pressure using high-pressure pump
at the beginning of extraction. The fluid then flows through an
extractor vessel containing the solute and the solvent. The fluid
then leaves the vessel and is depressurised to atmospheric conditions, using a heated metering valve, or restrictor. At the same
time, the extracted solute will precipitate or fall out of the fluid
solution, to be collected and quantified gravimetrically, or by some
conventional analytical technique. The solvent volume can either
be measured using a gas totaliser or by measuring the flow rate
of the solvent and the collected sample (Taylor, 1996).
Palm oil extraction experiments were carried out in a laboratory
scale extraction apparatus shown schematically in Fig. 1. The apparatus consists of HPLC Pump (Model PU-980, Jasco, Japan) with a
maximum capacity of 50 MPa (10,000 psi) which was used to deliver and regulate the R134a flow. Previous study by Mustapa et al.
(2009) showed that the flow rate of sub-critical R134a resulted in a
consistent oil solubility and shorter extraction time. Therefore, the
R134a flow rate was maintained at 3 ml/min for all extraction conditions. For each extraction run, 1 ± 0.001 g of UC sample was
placed in a 10-ml extractor (1.5 cm i.d. 8 cm) and the extractor
was placed in an oven (Model Memmert), which was used to control the operating temperature to within ±2 °C of the set point temperature for each run. The system pressure was controlled by a
back-pressure regulator (Model 880–81, Jasco, Japan) with an
8
9
5
3
6
18
14
15
17
16
2
7
10
13
11
4
12
1
Fig. 1. Schematic diagram of the R134a extraction apparatus (1) R134a cylinder, (2) Chiller (set at 5 °C), (3) HPLC pump, (4) flow meter indicator, (5) pressure meter, (6)
extraction cell, (7) oven (set the extraction temperature 40–80 °C), (8–9) temperature indicator, (10) heater (60–70 °C), (11) back-pressure regulator (BPR), (12) vial collector,
(13) mass flow meter, (14–18) valve).
264
A.N. Mustapa et al. / Food Chemistry 125 (2011) 262–267
accuracy of ±1 bar that was maintained at 80 ± 1 °C, in order to prevent oil from clogging in the tubing. The oil dissolved in the subcritical R134a was collected in a sample trap (a 4-ml amber glass
vial) by means of a heated valve that caused R134a to expand to
the ambient pressure. The palm oil collected was determined
gravimetrically using a balance (Model Mettler Toledo AL204).
R134a flow rate was measured by channelling it into a mass gas
flow meter (GFM17 Aalborg, Germany). The outlet tubing was
insulated with a Teflon insulator to prevent temperature drop solvent flowing from the extractor as well as from the oven.
Table 1
Palm oil yield percentages at various pressures and temperatures.
383
ðas ab Þ
100W
ð1Þ
where as = is absorbance of sample at 446 nm, ab=is the cuvette error, 383 = is the extinction coefficient for carotenoids, V is the volume used for analysis, W is weight of sample in grams. Cuvette
error was calculated based on three measurement repetitions.
% Oil Yield (g oil/g
sample)a
% Degree of Extraction
(YieldSFE/bYieldSohxlet)
40
60
80
100
60
80
100
60
80
100
48.57 ± 0.57
52.16 ± 0.04
56.47 ± 0.08
57.78 ± 0.47
62.06 ± 0.44
63.92 ± 3.07
57.83 ± 0.36
63.33 ± 1.40
66.06 ± 2.02
68.63
73.70
79.79
81.64
87.69
90.31
81.72
89.49
93.34
80
a
Concentration of b-carotene ¼ V Pressure
(bar)
60
2.3. Analysis of b-carotene concentration
The concentration of b-carotene was measured using a spectrophotometer (model UV–Vis, Shimadzu, Kyoto, Japan). Prior to analysis, sample extracts were melted at 60–70 °C and homogenised
thoroughly. About 20 mg of extracts were diluted with 7 ml of hexane. The solution was transferred to a 1-cm quartz cuvette and the
absorbance was read at 450 nm. This method was applied
according to MPOB Test Method (2005). Some previous studies
had determined the absorbance to be measured at 450 nm, which
corresponded to the maximum absorption of carotenoids (Franca,
Reber, Meireless, Machado, & Brunner, 1999; Hansen et al., 2001;
Mendes et al., 1999; Subra et al., 1997. Solubility of carotene in
R134a was calculated from the slope of the linear portion of the
curves, which is similar to the approach used for calculating the
solubility of oil in solvent (Ferreira, Nikolov, Doraiswamy, Meireles,
& Petenate, 1999). On the other hand, the concentration of b-carotene content is expressed as ppm using the following formula:
Temperature
(°C)
b
Oil yield from SFE method.
Soxhlet yield from UC sample was 70.86%.
also causes the oil yield to increase. Combination of both factors of
pressure and temperature contributed to the high oil yield at the
maximum pressure and temperature.
Table 1 also presents the degree of extraction, which indicates
the achievable oil yield using R134a solvent, over the oil yield derived from Soxhlet extraction. The degree of extraction demonstrates the extraction capability of R134a solvent. It is observed
that the degree of extraction increased with pressure and temperature. The variation of degree of extraction with pressure and temperature shows that the solvent was unable to dissolve oil in the
sample completely. This is because the extractable oil from samples depended on the solvent density (hence, the solvating power).
Cao and Ito (2003) performed supercritical extraction of grape
seed oil and found that 6% of grape seed oil was extracted, as compared to 10% total oil yield obtained using Soxhlet extraction. On
the other hand, it is observed from Table 1 that the extraction of
palm oil using sub-critical R134a can exceed 90% of extractable
oil, indicating that extraction using R134a as comparable to the
oil yield by Soxhlet extraction. This proves the suitability of
R134a to be used for extraction.
3.2. Solubility of b-carotene
3. Results and discussion
3.1. Extraction yield of palm oil
The oil yield is defined as the weight of total extracted oil (g) per
weight of sample feed (g) on wet weight basis at the given extraction temperature and pressure. The oil yields were calculated using
Eq. 2:
Yield ½g oil=g sample feed ¼
Extracted oil ðgÞ
100
Sample feed ðgÞ
ð2Þ
Palm oil yields and degree of extraction for palm oil processing
at various operating conditions are presented in Table 1. The degree of extraction was defined as weight of oil yield (g) per weight
of total oil extractable, which was obtained from Soxhlet extraction
(g).
From Table 1, it is observed that the highest total palm oil yield
was obtained at 100 bar and 80 °C, whereas the lowest was at
60 bar and 40 °C. The maximum palm oil yield achieved was
66.06%, and the highest degree of extraction of palm oil using
sub-critical R134a was 93.34%. Both the maximum yield and degree of extraction were obtained at 100 bar and 80 °C. This was
attributed to the increase in the solvent density with increased
pressure, and the increase in vapour pressure of the solute with
increasing temperature. Increasing pressure from 60 to 100 bar at
constant temperature causes the oil yield to increase. On the other
hand, increasing temperature from 40 to 80 °C at constant pressure
The analysis of b-carotene was performed at the final extraction
yield to investigate the total extractability of the component. The
typical curve for carotene fractions is shown in Fig. 2. From the figure, it is observed that, at both pressures of 60 and 80 bar, the linear portion of the curve during the first stage of extraction lay on a
single line. The overlapping region for carotenes occurred between
about 20 to 200 min of extraction time. This duration coincided
with the constant extraction rate for palm oil. This trend indicated
that the extraction of palm oil and carotenes were controlled by
the external mass transfer mechanism.
From the experimental work, it was observed that, from about
20 to 120 min of extraction time, the initial fractions were yellowish, whereas the latter fractions appeared as orange extracts. This
phenomenon was also observed by Markom et al. (2001). They stated that more b-carotene was extracted as the experiment proceeded. Franca et al. (1999) who carried out the extraction of
carotenoids from Mauritia flexuosa concluded that the largest
amount of carotenes was extracted in the diffusion-controlled period. Therefore, it is necessary to conduct the experiments until the
end of the extraction period. In order to observe the course of carotene extraction as well as to calculate its solubility, the concentration in each fraction was collected at regular time intervals.
Low-concentration of carotene sample at the beginning of
extraction may also lead to the same yield value at different conditions. Further increase in the mass of R134a used (as well as
extraction time) tended to increase the amount of extracted carotene at 60 bar, greater than the amount extracted at 80 bar. This
Carotene Concentration (mg/g oil)
A.N. Mustapa et al. / Food Chemistry 125 (2011) 262–267
6
5
4
3
2
60 bar
1
80 bar
0
0
500
1000
1500
2000
R134a Used (g)
Fig. 2. Typical curve of b-carotene concentration in oil fraction at 80 °C.
Solubility of beta-carotene (mg/g R134a)
behaviour can be attributed to the failure of R134a density (hence
solvating power) at 80 bar to penetrate and dissolve carotene. This
is because most b-carotene is located deep inside the solid particles
(Franca et al., 1999).
The solubility of b-carotene in R134a at various pressures and
temperatures is presented in Fig. 3. It is observed that the solubility
of b-carotene generally increased with the increase in extraction
pressure. However, it is interesting to note that at all temperatures
studied; the solubility of b-carotene decreased with pressure from
45 to 80 bar. Further pressure increase to 100 bar resulted in a solubility increase for b-carotene at 60 °C, apparently to its highest
level.
The previous observation may be due to the competing effects
of solubility at 80 bar between b-carotene and other more soluble
components present in the sample. Thus, a high solubility of the
co-extracted components with carotenoids tended to reduce the
solubility of b-carotene. However, further increase in pressure to
100 bar at all temperatures had increased the b-carotene solubility.
The increase might be due to high solubility of b-carotene compared to other components co-existing in carotenoids. Puah et al.
(2005) noted that the presence of other components being co-extracted with carotene could result in low solubility of b-carotene.
In terms of temperature effect, it was found that the solubility
of b-carotene increased with temperature from 40 to 80 °C at pressure below 80 bar. However, a crossover of solubility phenomena
was observed at pressures above 80 bar, between 60 and 80 °C.
This result is shown in Fig. 3. As pressure increased to more than
80 bar, the solubility of b-carotene at 80 °C was observed to de-
0.0012
o
40 C
60oC
0.0010
80oC
0.0008
0.0006
0.0004
0.0002
0.0000
30
50
70
Pressure (bar)
90
110
Fig. 3. Solubility of b-carotene in sub-critical R134a as a function of pressure.
265
crease to lower than at 60 °C. Under these conditions, there are
competing effects between the decrease in R134a density and increase in b-carotene vapour pressure when temperature increase
was expected to play a role in determining the solubility of
b-carotene.
However, the R134a density decrease predominates compared
to the vapour pressure effect. This phenomenon reduces the solubility of b-carotene at 80 °C. In this case, the increase in b-carotene
vapour pressure has little influence on the solubility. On the other
hand, the maximum solubility achieved at 60 °C was due to the
R134a density (hence solvating power) being higher than the density at 80 °C. This result was consistent with the general relationship governing density–temperature–pressure, where density
generally decreases with increasing temperature at constant
pressure.
The capability to selectively extract compounds such as b-carotene (in this study) highlights the unique feature of SFE technology.
Note from Fig. 3 that the highest solubility is obtained at 100 bar
and 60 °C. This indicates that high b-carotene selectivity in R134a
occurred at the highest pressure and moderate temperature. Low
solubility of carotenoids at the highest temperature (80 °C) may
be due to some degradation of b-carotene at that point. On the
other hand, low solute vapour pressure at 40 °C may have prevented the solutes from leaving the solid matrix into the fluid,
thereby resulting in lower b-carotene solubility.
Markom et al. (2001) on the other hand reported that, at
200 bar and temperatures of 40–60 °C small amounts of b-carotene
were extracted. Franca and Meireless (1997)performed oil extraction from pressed palm oil fibres using supercritical CO2 to recover
carotenes. They found that the total amount of carotenes remained
constant during the course of extraction at 300 bar, but showed a
significant increase at 200 and 250 bar. Hansen et al. (2001) investigated the effects of temperature on the solubility of b-carotene in
SC-CO2 and in sub-critical R134a. They reported that the solubility
of b-carotene in R134a increased with pressure and decreased with
temperature. Our findings show that the solubility of b-carotene
decreased with pressure at 80 bar, contrary to the findings of Hansen et al. (2001). They also noted that the solubility in R134a as
rather low, and that the solubility deviations between the two solvents were relatively small. On the other hand, Lau et al. (2006),
who investigated the extraction of palm oil from palm mesocarp
using supercritical carbon dioxide, reported the carotene content
increased gradually when increasing the operating temperature
and pressure from 40 to 80 °C and 14 to 30 MPa.
The solubility found in this study was slightly different from
some of the findings reported on the solubility of b-carotene in
supercritical CO2 (Johannsen & Brunner, 1997; Mendes et al.,
1999; Sakaki, 1992; Subra et al., 1997 and Sovová et al., 2001).
They reported that b-carotene solubilities increased with pressure
at constant temperature for experiments conducted at a pressure
range of between 120 and 350 bar and a temperature range of between 40° to 80 °C. Fig. 4 compares the solubilities derived from
several works. Note that the solubilities achieved in this work
are an order of magnitude lower than those found in other studies.
However, Saldaña et al. (2010) who investigated the extraction of
lycopene and b-carotene from tomato skin + pulp at 400 bar and
40 and 70 °C, using SC-CO2, SC-CO2+5% canola oil and SC-CO2+5%
ethanol, reported that the solubility of b-carotene tended to increase with increasing temperature, and was in the range of
6.2 ± 0.9 107 to 18 ± 4 107 mole fraction.
The maximum carotene amount was obtained at 100 bar and
60 °C while the smallest was at 80 bar and 40 °C. The discrepancies
between the results of this work and those of other studies were
probably due to the different characteristics of CO2 and R134a solvents apart from the lower pressures used in this work compared
to the pressures used with CO2 solvent. The polarity of R134a
A.N. Mustapa et al. / Food Chemistry 125 (2011) 262–267
Solubility (vapour fraction)
266
1.4E-06
This Work
1.2E-06
1.0E-06
Johannsen
and Brunner,
1997
8.0E-07
Mendes et al.,
(1999)
Subra et al.,
(1997)
6.0E-07
4.0E-07
2.0E-07
0.0E+00
0
100
200
300
400
Pressure (bar)
Fig. 4. Comparison of carotene solubilities among several publications.
Concentration of beta-carotene
(ppm)
molecules may not be adequate in dissolving the non-polar
molecules of b-carotene. This factor was also expected to contribute to the differences in carotene solubilities. Hansen et al. (2001)
also stated that the low solubility of carotene in R134a as
compared to CO2 was because R134a is a polar compound while
carotene is a non-polar compound. Finally, the different types of
sample used may also have caused the solubility discrepancies.
Johannsen and Brunner (1997) and Puah et al. (2005) noted that
different materials or different methods used for the solubility
measurement as well as the purity of b-carotene could also lead
to solubility differences. Saldaña et al. (2010) also reported that
the b-carotene solubility obtained from multi-component
measurement was lower than the solubility obtained from binary
measurement. They attributed the difference to the type of sample
matrix as well as the components interactions, which can change
over time throughout the dynamic extraction period. On the other
hand, Lau et al. (2006) reported carotenes have low solubility due
to high molecular weight as well as low vapour pressure.
The analysis on b-carotene was performed during the final
extraction yield to investigate the total extractability of the component. It was observed that the concentration of b-carotene increased with increase in extraction pressure as shown in Fig. 5.
However, it is interesting to note that at all pressures studied,
the concentration of b-carotene decreased markedly at 80 bar, with
temperature of 60 °C giving the lowest b-carotene concentration.
This happened possibly due to the high solubility of undesired
components which were co-extracted with carotenoids at 80 bar,
thereby resulting in lower b-carotene concentration. However,
the b-carotene concentration tended to rise again after the pressure was increased to 100 bar at all the temperatures studied.
The increase that was observed after 80 bar may possibly be due
900
to the higher solubility of b-carotene as compared to the solubility
of other components co-existing in carotenoids. The variation of
b-carotene concentration demonstrated the system’s selective
extraction capability, which is a special characteristic of SFE technology. The highest concentration was obtained at 100 bar and
60 °C. This means that b-carotene extraction was selectively maximised at the highest pressure and moderate temperature. Low solubility of carotenoids at the highest temperature (80 °C) may
probably be due to a small degradation of b-carotene as well as
its low solubility in R134a at this temperature. On the other hand,
at 40 °C the solutes have apparently lower tendency to escape from
the solid matrix to the fluid phase due to the low solute vapour
pressure. This may have led to the low b-carotene concentration
at 40 and 80 °C.
3.3. Statistical analysis (ANOVA)
Statistical analysis (ANOVA) of b-carotene solubility in subcritical R134a was performed in Excel 2007. It was found that
the effect of both temperature (p-value = 0.075) and pressure
(p-value = 0.596) at 95% confidence level were negligible. However,
temperature effect on b-carotene solubility was slightly more significant compared to the effect of pressure. Thus, it can be concluded that the effect of temperature on b-carotene vapour
pressure was more important in influencing the solubility of b-carotene in sub-critical R134a.
4. Conclusion
The yield of palm oil extracted from palm mesocarp using
R134a at sub-critical conditions increased with increasing pressure
and temperature. The maximum yield of 66.06% was achieved at
100 bar and 80 °C. The extraction of palm oil and the recovery of
b-carotene using sub-critical R134a are feasible since the extracted
b-carotene concentration was higher in this case, as compared to
the concentration obtained from conventional processing. The
highest concentration of b-carotene of 780 ppm was obtained at
100 bar and 60 °C and the lowest b-carotene concentration of
370 ppm was obtained at 80 bar and 40 °C. The results show that
simultaneous extraction of palm oil and recovery of carotenoids
using R134a is feasible.
Acknowledgement
The authors would like to thank the Ministry of Science, Technology and Innovation of Malaysia for the financial support provided through IRPA Project Grant No. 74213. The authors would
also like to thank MALPOM Industries Sdn Bhd, Nibong Tebal, Penang, Malaysia for supplying the fresh palm fruits used in the
experiments.
o
40 C
800
700
References
60oC
o
80 C
600
500
400
300
200
30
50
70
Pressure (bar)
90
110
Fig. 5. Effect of pressure on b-carotene concentration at different temperatures.
Bharath, R. (2003). Opportunities for Supercritical Fluid Extraction in Industrial
Processing. International mini-Symposium on Supercritical Fluid Extraction, 16–17
January, Sendai, Japan, 1–3.
Birtigh, A., Johannes, M., Brunner, G., & Nair, N. (1995). Supercritical-fluid extraction
of oil-palm components. The Journal of Supercritical Fluids, 8, 46–50.
Brunner, G. (1994). Gas extraction: An introduction to fundamentals of supercritical
fluids and the application to separation processes. New York: Steinkopff
Darmstadt Springer.
Brunner, G. (2005). Supercritical fluids: technology and application to food
processing. Journal of Food Engineering, 67, 21–33.
Cao, X., & Ito, Y. (2003). Supercritical fluid extraction of grape seed oil and
subsequent separation of free fatty acids by high-speed counter-current
chromatography. Journal of Chromatography A, 1021(1–2), 117–124.
Catchpole, O. J., & Proells, K. (2001). Solubility of Squalene, Oleic Acid, Soya Oil, and
Deep Sea Shark Liver Oil in Subcritical R134a from 303 to 353 K. Industrial
Engineering Chemistry Research, 40(3), 965–972.
A.N. Mustapa et al. / Food Chemistry 125 (2011) 262–267
Corr, S. (2002). 1, 1, 1, 2-Tetrafluoroethane; from refrigerant and propellant to
solvent. Journal of Fluorine Chemistry, 118, 55–67.
Cygnarowicz, M. L., Maxwell, R. J., & Seider, W. D. (1990). Equilibrium solubilities of
b-carotene in supercritical carbon dioxide. Fluid Phase Equilibria, 59, 57–71.
De Castro, L., Valcárcel, M., & Tena, M. T. (1994). Analytical supercritical fluid
extraction. German: Springer-Verlag.
Ferreira, S. R. S., Nikolov, Z. L., Doraiswamy, L. K., Meireles, M. A. A., & Petenate, A. J.
(1999). Supercritical fluid extraction of black pepper (Piper nigrun L.) essential
oil. Journal of Supercritical Fluids, 14, 235–245.
França, L. F., & Meireles, M. A. A. (2000). Modeling the extraction of carotene and
lipids from pressed palm oil (Elaes Guineensis) fibers using supercritical CO2.
Journal of Supercritical Fluids, 18, 35–47.
Franca, L. R., & Meireless, M. A. A. (1997). Extraction of oil from pressed palm oil
(Elaes guineensis) fibers using supercritical CO2. Ciência e Technologia de
Alimentos, 17, 384.
Franca, L. F., Reber, G., Meireless, M. A. A., Machado, N. T., & Brunner, G. (1999).
Supercritical extraction of carotenoids and lipids from buriti (Mauritia flexuosa),
a fruit from the Amazon region. Journal of Supercritical Fluids, 14, 247–256.
Hansen, B. N., Harvey, A. H., Coelho, J. A. P., Palavra, A. M. F., & Bruno, T. J. (2001).
Solubility of capsaicin andb-carotene in supercritical carbon dioxide and in
halocarbons. Journal of Chemical Engineering Data, 46(5), 1054–1058.
Johannsen, M., & Brunner, G. (1997). Solubilities of the fat-soluble vitamins A, D, E,
and K in supercritical carbon dioxide. Journal of Chemical Engineering Data, 42,
106–111.
Lau, H. L. N., Choo, Y. M., Ma, A. N., & Chuah, C. H. (2006). Characterization and
supercritical carbon dioxide extraction of palm oil (Elaeis Guineensis). Journal of
Food Lipids, 13, 210–221.
Lau, H. N., Choo, Y. M., Ma, A. N., & Chuah, C. H. (2008). Selective extraction of palm
carotene and vitamin E from fresh palm-pressed mesocarp fiber (Elaeis
guineensis) using supercritical CO2. Journal of Food Engineering, 84, 289–296.
Markom, M., Singh, H., & Hasan, M. (2001). Supercritical CO2 fractionation of crude
palm oil. Journal of Supercritical Fluids, 20, 45–53.
Mendes, R. L., Nobre, B. P., Coelho, J. P., & Palavra, A. F. (1999). Solubility of bcarotene in supercritical carbon dioxide and ethane. Journal of Supercritical
Fluids, 16, 99–106.
267
MPOB Test Method (2005), Determination of Carotene Content. Malaysian Palm Oil
Board, Method No. p 2.6, pp. 194–197.
Mustapa, A. N., Manan, Z. A., Mohd Azizi, C. Y., Nik Norulaini, N. A., & Mohd Omar, A.
K. (2009). Effect of parameters on yield for sub-critical R34a extraction of palm
oil. Journal of Food Engineering, 95, 606–616.
Nik Norulaini Ahmad, A. O., Fatehah, M. O., Banana, A. A. S., Zaidul, I. S. M., & Mohd,
Omar (2008). Sterilization and extraction of palm oil from screw pressed palm
fruit fiber using supercritical carbon dioxide. Separation and Purification
Technology, 60, 272–277.
Perrut, M. (2000). Supercritical fluid applications: Industrial developments and
economic issues. Industrial Engineering Chemistry Research, 39, 4531–4535.
Puah, C. W., Choo, Y. M., Ma, A. N., & Chuah, C. H. (2005). Supercritical fluid
extraction of palm carotenoids. American Journal of Environmental Science, 1(4),
264–269.
Sakaki, K. (1992). Solubility of b-carotene in Dense CO2 and Nitrous Oxide from 308
to 323 K and from 9.6 to 30MPa. Journal of Chemical Engineering Data, 37,
249–251.
Saldaña, M. D. A., Temelli, F., Guigard, S. E., Tomberli, B., & Gray, C. G. (2010).
Apparent solubility of lycopene and b-carotene in supercritical CO2,
CO2 + ethanol and CO2 + canola oil using dynamic extraction of tomatoes.
Journal of Food Engineering, 99, 1. 1–8.
Škerget, M., Knez, Ž., & Habulin, M. (1995). Solubility of b-carotene and oleic acid in
dense co2 and data correlation by a densitybased model. Fluid Phase Equilibria,
109, 131–138.
Sovová, H., Stateva, R. P., & Galushko, A. A. (2001). Solubility of b-carotene in
supercritical co2 and the effect of entrainers. Journal of Supercritical Fluids, 21,
195–203.
Subra, P., Castellani, S., Ksibi, H., & Garrabos, Y. (1997). Contribution to the
determination of the solubility of b-carotene in supercritical carbon dioxide and
nitrous oxide: experimental data and modeling. Fluid Phase Equilibria, 131,
269–286.
Taylor, L. T. (1996). Supercritical fluid extraction. Inc: John Wiley & Sons.
Wood, C. D., & Cooper, A. I. (2003). Synthesis of polystyrene by dispersion
polymerization in 1, 1, 1, 2-tetrafluoroethane (R134a) using inexpensive
hydrocarbon monomer stabilizers. Macromolecules, 36, 7534–7542.