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Characterization of the Yellow Croaker <italic>Larimichthys polyactis</italic>muscle Oil Extracted with Supercritical Carbon Dioxide and an Organic Solvent
Characterization of the Yellow Croaker Larimichthys polyactismuscle Oil Extracted with Supercritical Carbon Dioxide and an Organic Solvent
Fisheries and aquatic sciences. 2012. Dec, 15(4): 275-281
Copyright ©2012, The Korean Society of Fisheries and Aquatic Science
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Received : October 10, 2012
  • Accepted : November 11, 2012
  • Published : December 30, 2012
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About the Authors
Joo-Hee Lee
A. K. M. Asaduzzaman
Jun-Ho Yun
Jun-Hyun Yun
Byung-Soo Chun
bschun@pknu.ac.kr
Abstract
Yellow croaker Larimichthys polyactis muscle oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-CO 2 ), in a semi-batch flow extraction process. SC-CO 2 was applied at temperature 35℃ to 45℃ and 150℃ to 250℃ bar of pressure. The flow rate of CO 2 (27.79 g/min) was constant throughout the entire 1.5 h extraction period. The oil extraction yield was influenced by the physical properties of SC-CO 2 at different temperatures and pressures. The extracted oil was analyzed by gas chromatography to determine the fatty acid composition. According to our results, the SC-CO 2 extracted oil was high in eicosapentaenoic acid and docosahexaenoic acid. In addition, the SC-CO 2 extracted oil showed greater stability than n -hexane extracted oil based on the peroxide value and acid value. Thus, the quality of yellow croaker oil obtained by SC-CO 2 extraction was slightly higher than that of oil obtained by n -hexane extraction.
Keywords
Introduction
Yellow croaker Larimichthys polyactis contains large amounts of lipids and proteins and many kinds of biologically active compounds (Ai et al., 2006). Marine lipids, especially polyunsaturated fatty acids (PUFAs), have attracted recent attention given their health benefits. Thus, commercial interest exists in obtaining PUFAs, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These omega-3 fatty acids are essential for normal growth and development and may play an important role in the prevention and treatment of coronary artery disease, hypertension, arthritis, inflammatory and autoimmune disorders, and cancer (Corrêa et al., 2008).
Generally, lipids are extracted using organic solvents, and several methods have been developed for extracting fish oils with varying yields. The extraction and purification of lipids by conventional methods, including hexane extraction, vacuum distillation, urea complexation, and conventional crystallization, have the disadvantage of requiring processing at high temperatures, resulting in the decomposition or degradation of these heat-labile compounds. Moreover, organic solvents are harmful to human health and the environment (Staby and Mollerup 1993; Hultin, 1994; Sahena et al., 2010).
Supercritical fluid extraction (SFE) is an efficient alternative for the extraction of natural substances from foods (Mendes et al., 2003; Sun and Temelli, 2006). In recent years, the use of SFE for the removal of organic compounds from different liquid and solid matrices has attracted a great deal of attention. This technique has some advantages over conventional separation techniques, largely due to the unique physical properties of supercritical fluids. Supercritical fluid separation using carbon dioxide (CO 2 ) as the solvent carries offers
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Schematic diagram of supercritical carbon dioxide extraction process. BPR, back pressure regulator.
potential advantages because it is nonflammable, nontoxic, inert to most materials, inexpensive, and can be used under mild operational conditions (Ge et al., 2002). Moreover, it has been widely used in many industrial applications, including the extraction of fish oil for PUFAs, the decaffeination of coffee, the extraction of hops and carotenoids, the synthesis of polymers, and the formation and purification of nanoparticles (Temelli et al., 1995; Lim et al., 2002; Kopcak and Mohamed, 2005; Létisse et al., 2006; Machmudah et al., 2006; Rubio- Rodriguez et al., 2008; Sahena et al., 2010). Several studies have investigated the extraction of oils rich in PUFAs using supercritical carbon dioxide (SC-CO 2 ). This process, which has a negligible environmental impact, represents a potential tool for changing the relative concentration of various lipid moieties (Eisenbach, 1984; Rizvi et al., 1998; Temelli et al., 1995; Perretti et al., 2003).
The objective of this study was to extract oil from yellow croaker muscle using SC-CO 2 and hexane. The fatty acid compositions of the oils produced using these different extraction processes were then analyzed, and the stability of the SC-CO 2 and hexane extracted oils was compared.
Materials and Methods
- Materials
Yellow croaker (average weight, 17.5 cm; sample length, 158 g) was collected from Busan Cooperative, Fish Market (Busan, Korea). Muscle was separated and washed thoroughly with cold water. Pure CO 2 (99.99%) was supplied by KOSEM (Yangsan, Korea). All reagents used in this study were of analytical or high-performance liquid chromatography grade.
- Sample preparation
The yellow croaker muscle samples were dried in a freeze-dryer for about 72 h, then crushed with a mechanical blender and sieved through a mesh size, 2 mm. The samples were stored at -20℃ prior to SC-CO 2 or hexane extraction.
- SC-CO2extraction
A laboratory-scale SFE process was performed ( Fig. 1 ). The apparatus can be operated at pressures up to 300 bar. A total of 30 g of freeze dried raw yellow croaker muscle was placed in a 200 mL stainless steel extraction vessel with a thin layer of cotton at the bottom. A second layer of cotton was applied across the top of the sample. CO 2 was pumped at a constant pressure into the extraction vessel with a high pressure pump set at the desired pressure. A back pressure regulator was used to control the pressure of CO 2 . The extraction temperature was maintained using a water bath connected to the extraction vessel. The flow rate and accumulated gas volume passing through the apparatus were measured by a gas flow meter. The effects of temperature and pressure on lipid extraction from yellow croaker were measured at 35-45℃ and 150-250 bar. The flow rate of CO 2 (27.79 g/min) was held constant throughout the 1.5 h extraction period. A modifier was not used. The extracted oil was collected in a vial and stored at -20℃ until further analysis.
- Hexane extraction
The extraction procedure was carried out with or without Soxhlet apparatus with hexane as the solvent. During use of the Soxhlet apparatus, 2 g of freeze dried raw yellow croaker muscle was placed in an extraction thimble and the extraction process was run for 24 h, until the color of the condensed solvent at the top of the apparatus was clear. For extraction without the Soxhlet apparatus using, 40 g of freeze dried raw yellow croaker muscle was placed with 200 mL of hexane into a beaker and stirred for 24 h by a magnetic stirrer at 45℃ and 250 rpm. After extraction, the hexane solution was evaporated in a rotary vacuum evaporator at 40℃. The extracted oil was collected in a vial and stored at -20℃ until further analysis.
- Determination of the fatty acid composition
Gas chromatographic analysis was carried out to determine the fatty acid composition of yellow croaker muscle oil obtained using SC-CO 2 or hexane (without Soxhlet apparatus). Gas chromatography-mass spectrometry was performed by a 6890 Agilent Technologies (Wilmington, DE, USA) gas chromatograph with a fused silica capillary column (length, 100 m; internal diameter, 25 mm; length of film, 0.2 μm; Supelco, Bellefonte, PA, USA). Fatty acid methyl esters were prepared according to the Official Method and Recommended Practices of the AOCS Ce 2-66 (1998). Nitrogen was used as a carrier gas (1.0 mL/min). The oven was programmed to start at a constant temperature of 130℃ for 3 min, and then to increase 240℃ at a rate of 4℃/min and hold at 240℃ for 10 min. The injector and detector were both set at 250℃. Fatty acid methyl esters were identified by comparison of the retention time with a standard fatty acid methyl ester mixture (Supelco).
- Measurement of oil stability
Several parameters may be used to determine the deterioration of oil. In this study, oil deterioration was monitored by evaluating the acid value (AV) and peroxide value (POV).
- Measurement of the AV
The AV was assessed according to the Official Method and Recommended Practices of the AOCS Cd 3d-63 (1998). A total of 1 g of sample was dissolved in 100 mL of ether:ethanol (1:1) and shaken. Next, four drops of phenolphthalein were added as an indicator. The solution was titrated with 0.1 N KOH-ethanol until it turned pink. The AV, expressed as mg KOH per g of sample, was calculated using the formula.
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where A is the volume of KOH-ethanol solution of the titration (mL), F is concentration of KOH-ethanol, S is the mass of oil (g), and 56.11 is the molecular weight of KOH.
- Measurement of the POV
The POV was determined according to the Official Method and Recommended Practices of the AOCS Cd 8-53 (1998). A total of 1.0 g of yellow croaker muscle oil was dissolved in 6 mL of acetic acid-chloroform (3:2). Next, 0.1 mL of saturated KI was added, and the mixture was allowed to stand with occasional shaking for 1 min. Distilled water (6 mL) was immediately added to the solution. The solution was titrated with 0.1 N sodium thiosulfate until the yellow color of the iodine had almost disappeared. Next, 0.4 mL of starch indicator solution was added and again titrated until the blue color disappeared. A blank determination was conducted with the same procedure. The POV, expressed as milliequivalents (meq) peroxide/ 1,000 g sample, was calculated using the equation
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where S is the volume of the titrant (mL), B is the volume of titrant blank (mL), N is the normality of the sodium thiosulfate solution, and M is the mass of the sample (g).
- Statistical analysis
All experiments were carried out in duplicate. The data are expressed as the mean ± standard deviation. Differences ( P < 0.05) between means were identified by descriptive statistics using SPSS version 15.0 (SPSS, Inc., Chicago, IL, USA).
Results and Discussion
- SC-CO2extraction
The extraction curves for yellow croaker muscle oil prepared using SC-CO 2 at different temperatures (35℃, 40℃, and 45℃) and pressures (150, 200, and 250 bar) are shown in Fig. 2 . The highest oil yield obtained by SC-CO 2 extraction was 6.41 ± 0.08 g/30 g of yellow croaker muscle at 35℃ and 250 bar. The temperature and pressure applied greatly affected the oil solvating power of SC-CO 2 , and hence, the yield. Depending on the pressure and temperature, the amount of oil extracted increased as the mass of CO 2 increased. The amount of extracted oil per solvent (CO 2 ) mass used increased constantly throughout the extraction period, until almost all of the oil was extracted. The slope of the extraction curve (35℃
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Supercritical carbon dioxide of oil from yellow croakers muscle at different extraction conditions. (A) 35-45℃ and 150-250 bar, (B) 45℃ and 150- 250 bar, (C) 40℃ and 150-250 bar, (D) 35℃ and 150-250 bar, and (E) 150 bar and 35-45℃. Results are the mean value of two replicates ± SD.
and 250 bar) indicated that SC-CO 2 extracted almost all of the yellow croaker muscle oil. At a constant temperature, the amount of oil extracted from yellow croaker muscle increased with the pressure. Due to the increase in pressure, the density, and hence, the solvating power of SC-CO 2 increased. At a constant pressure, the amount of oil extracted from yellow croaker muscle decreased as the temperature increased. The solvating power of supercritical fluids decreases with a rise in temperature because the density decreases dramatically as the temperature increases at low pressures. The effect of pressure can be attributed to the increase in solvating power and the strengthening of intermolecular interactions (Morita and Kajimoto, 1990; Bai et al., 1997; Bulgarevich et al., 2002). Similar results were found in the extraction of oil from green coffee (De Azevedo et al., 2008) and boiled anchovy (Park et al., 2008).
- Comparison of the oil yield by SC-CO2and hexane extraction
As shown in Fig. 3 , the total amount of oil obtained from yellow croaker muscle by Soxhlet extraction using hexane was 19.70 ± 0.42% (w/w freeze dried raw sample), while the highest total amount of oil obtained by SC-CO 2 extraction was 21.36 ± 0.28% at 250 bar and 35℃ ( Fig. 2 ). Considering that the extraction of oil using SC-CO 2 at 250 bar and 35℃ was complete, the yield by hexane extraction was almost 92.23%. The observed difference in maximum yield may have been
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The percentage of total amount of oil from yellow croaker muscle at supercritical carbon dioxide (SC-CO2) and hexane extraction. Results are the mean value of two replicates ± SD.
due to variations in the processing unit, operating conditions, sample size, or percentage of lipid in the sample.
- Fatty acid composition
The fatty acid compositions of the oils obtained by SC-CO 2 and hexane extraction without Soxhlet apparatus are shown in Table 1 . In total, 20 fatty acids were identified in the extracts. The highest percentage of total fatty acids was identified
Fatty acid compositions percentage of yellow croakers muscle oil obtained by SC-CO2and hexane extractionSC-CO2, supercritical carbon dioxide; EPA, eicosapentaenoic acid; DHA, docosahexaenoic acid.*Data are the mean value of two replicates. Standard deviation (SD) of the fatty acid constituents were on the order of about ± 3% (SD data not shown).
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Fatty acid compositions percentage of yellow croakers muscle oil obtained by SC-CO2 and hexane extraction SC-CO2, supercritical carbon dioxide; EPA, eicosapentaenoic acid; DHA, docosahexaenoic acid. *Data are the mean value of two replicates. Standard deviation (SD) of the fatty acid constituents were on the order of about ± 3% (SD data not shown).
at 250 bar and 35℃. Among saturated fatty acids, palmitic acid (C16:0) was present at the highest concentration 23.94% to 27.08% of the total identified fatty acids. Arachidic acid, which was found under all extraction conditions, is used to produce of detergents, photographic materials, and lubricants. Among monounsaturated fatty acids, oleic acid (C18:0) was also found in substantial amounts 21.32% to 24.49% of the total identified fatty acids. DHA (C22:6) was present in yellow croaker muscle oil at higher amounts than other PUFAs. The percentages of EPA (C20:5) and DHA (C22:6) in the total identified fatty acids ranged from 5.73% to 6.58% and 6.74% to 9.19%, respectively. The PUFA composition in yellow croaker muscle oil was identical to that in marine fish oils such as cod liver oil and anchovy oil, which contain about 14-31% of EPA and DHA (AOCS, 1997).
Additionally, the oil extracted using SC-CO 2 had a higher percentage of PUFAs than the oil extracted using hexane, perhaps because of the high temperature and long extraction period used compared with SC-CO 2 extraction. A long extraction period with heat may lead to the thermal degradation of fatty acids, especially unsaturated fatty acids. Similar results have been reported for the fatty acid profile of hake by-products (Rubio-Rodríguez et al., 2008)
- Oil stability
Marine fish oil contains high levels of PUFAs, and the speed at which oil deteriorates depends strongly on its production and storage conditions (Kamal-Eldin and Yanishlieva, 2002). The AV and POV of the oils extracted in this study using SC-CO 2 and hexane are given in Table 2 . The AV and POV were fairly high for hexane extracted oil compared to the SC-CO 2 extracted oil. Also, the oil obtained at a higher extraction temperature using SC-CO 2 had a higher AV and POV. The AV is used to represent the acidity of oil; a low AV indicates high oxidative stability (Essien et al., 2012). In contrast, the POV of an oil or fat is used as a measurement of rancidity, which occurs by autoxidation. Low exposure to oxygen during the SC-CO 2 extraction process caused minimal oxidationnd POV of yellow croaker muscle oil under different SC-CO 2 extraction conditions ranged from 5.61 ± 0.08 to 9.54 ± 0.17 mg KOH/g and 7.40 ± 0.08 to 10.90 ± 0.14 meq/1,000 g, respectively. The respective AV and POV of soybean oil were found to be 9.75% and 0.5 meq/g (Ashaye and Olusoji, 2006), which is higher than the values obtained for yellow croaker oil. However, the oil extracted using SC-CO 2 showed higher stability compared to the oil obtained by hexane extraction without Soxhlet apparatus.
Acid value and peroxide value of yellow croaker muscle oil obtained by SC-CO2and hexane extractionSC-CO2, supercritical carbon dioxide.*Results are the mean value of two replicates ± SD.
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Acid value and peroxide value of yellow croaker muscle oil obtained by SC-CO2 and hexane extraction SC-CO2, supercritical carbon dioxide. *Results are the mean value of two replicates ± SD.
Acknowledgements
This research was supported by 2011 High Value Added Food Industry Professional Human Resources Development Project, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
References
Ai Q , Mai K , Tan B , Xu W , Duan Q , Ma H , Zhang L 2006 Replacement of fish meal by meat and bone meal in diets for large yellow croaker, Pseudosciaena crocea. Aquaculture 260 255 - 263
American Oil Chemist’s Society (AOCS). 1997 Physical and Chemical Characteristics of Oils, Fats and Waxes. American Oil Chemist’s Society Champaign, IL, US 54 -
American Oil Chemist’s Society (AOCS). 1998 Official Methods of Analysis. 5th ed. American Oil Chemist’s Society Champaign, IL, US
Ashaye OA , Olusoji OC 2006 Evaluation of some quality attributes of soybean oils in Ibadan. Afr J Agric Res 1 17 - 19
Bai S , Taylor CMV , Liu F , Mayne CL , Pugmire RJ , Grant DM 1997 CO2clustering of 1-decanol and methanol in supercritical fluids by13C nuclear spin-lattice relaxation. J Phys Chem B 101 2923 - 2928
Bulgarevich DS , Sako T , Sugeta T , Otake K , Takebayashi Y , Kamizawa C , Horikawa Y , Kato M 2002 The role of general hydrogenbonding interactions in the solvation process of organic compounds by supercritical-CO2/n-alcohol mixtures. Ind Eng Chem Res 41 2074 - 2081
Corrêa APA , Peixoto CA , Gonçalves LAG , Cabral FA 2008 Fractionation of fish oil with supercritical carbon dioxide. J Food Eng 88 381 - 387
De Azevedo ABA , Kieckbush TG , Tashima AK , Mohamed RS , Mazzafera P , Vieira de Melo SAB 2008 Extraction of green coffee oil using supercritical carbon dioxide. J Supercrit Fluids 44 186 - 192
Eisenbach W 1984 Supercritical fluid extraction: a film demonstration. Ber. Bunsenges. J Phys Chem 88 882 - 887
Essien EA , Umoren SA , Essien EE , Udoh AP 2012 Preparation and evaluation of Cucumeropsis mannii Naud seed oil metallic soaps as driers in gloss paint. J Mater Environ Sci 3 477 - 484
Ge Y , Ni Y , Chen Y , Cai T 2002 Optimization of the supercritical fluid extraction of natural vitamin E from wheat germ using response surface methodology. J Food Sci 67 239 - 243
Hultin HO 1994 Oxidation of lipids in seafoods. In: Seafoods: Chemistry, Processing Technology and Quality. Shahidi F and Botta JR, eds. Chapman and Hall, Academy Press London, GB 49 - 74
Kamal-Eldin A , Yanishlieva NV 2002 n-3 fatty acids for human nutrition: stability considerations. Eur J Lipid Sci Technol 104 825 - 836
Kopcak U , Mohamed RS 2005 Caffeine solubility in supercritical carbon dioxide/co-solvent mixtures. J Supercrit Fluids 34 209 - 214
Létisse M , Rozières M , Hiol A , Sergent M , Comeau L 2006 Enrichment of EPA and DHA from sardine by supercritical fluid extraction without organic modifier I. Optimization of extraction conditions. J Supercrit Fluids 38 27 - 36
Lim GB , Lee SY , Lee EK , Haam JS , Kim WS 2002 Separation of astaxanthin from red yeast Phaffia rhodozyma by supercritical carbon dioxide extraction. Biochem Eng J 11 181 - 187
Machmudah S , Shotipruk A , Goto M , Sasaki M , Hirose T 2006 Extraction of astaxanthin from Haematococcus pluviaris using supercritical-CO2and ethanol as entrainer. Ind Eng Chem Res 45 3652 - 3657
Mendes RL , Nobre BP , Cardoso MT , Pereira AP , Palavra AF 2003 Supercritical carbon dioxide extraction of compounds with pharmaceutical importance from microalgae. Inorg Chim Acta 356 328 - 334
Morita A , Kajimoto O 1990 Solute-solvent interaction in nonpolar supercritical fluid: a clustering model and size distribution. J Phys Chem 94 6420 - 6425
Park JY , Lee MK , Uddin S , Chun BS 2008 Removal of off-flavors and isolation of fatty acids from boiled anchovies using supercritical carbon dioxide. Biotechnol Bioprocess Eng 13 298 - 303
Perretti G , Miniati E , Montanari L , Fantozzi P 2003 Improving the value of rice byproducts by SFE. J Supercrit Fluids 26 63 - 71
Rizvi SSH , Chao RR , Liaw YJ 1998 Concentration of omega-3 fatty acids from fish oil using supercritical carbon dioxide. In: Supercritical Fluid Extraction and Chromatography: Techniques and Applications. Vol. 366. Charpentier BA and Sevenants MR, eds. American Chemical Society Washington, DC, US 89 - 108
Rubio-Rodríguez N , De Diego SM , Beltrán S , Jaime I , Sanz MT , Rovira J 2008 Supercritical fluid extraction of the omega-3 rich oil contained in hake (Merluccius capensis-Merluccius paradoxus) byproducts: study of the influence of process parameters on the extraction yield and oil quality. J Supercrit Fluids 47 215 - 226
Sahena F , Zaidul ISM , Jinap S , Yazid AM , Khatib A , Norulaini NAN 2010 Fatty acid compositions of fish oil extracted from different parts of Indian mackerel (Rastrelliger kanagurta) using various techniques of supercritical-CO2extraction. Food Chem 120 879 - 885
Staby A , Mollerup J 1993 Separation of constituents of fish oil using supercritical fluids: a review of experimental solubility, extraction, and chromatographic data. Fluid Phase Equilibria 91 349 - 386
Sun M , Temelli F 2006 Supercritical carbon dioxide extractions of carotenoids from carrot using canola oil as a continuous cosolvent. J Supercrit Fluids 37 397 - 408
Temelli F , LeBlanc E , Fu L 1995 Supercritical CO2extraction of oil from Atlantic Mackerel (Scomber scombrus) and protein functionality. J Food Sci 60 703 - 706