Comparative of Physico-Chemical Properties of Wheat Germ Oil Extracted with Cold Press and Supercritical CO2 Extraction

Document Type : Research Article


1 Department of Food Engineering, Faculty of Agriculture, Selcuk University, 42031 Konya, TURKEY

2 Food Engineering, Zade Oil Company, Konya, TURKEY


In this study, moisture content, free fatty acids, peroxide, iodine value, unsaponifiable matter, saponification value, fatty acid composition and tocopherol contents of wheat germ oil obtained by SC-CO2 extraction and cold press technology were investigated. Moisture, free fatty acid (FFA), peroxide value, iodine value, unsaponifiable matter and saponification value of cold press and supercritical CO2 extraction method oils were established as 0.097% and 13.32, 0.84% and 5.9%, 8.9 meq O2/kg and 15.8, 132 and 128, 6.5 g/kg and 8.04 and 197 and 182mg KOH/g, respectively. Major fatty acids of samples were determined as palmitic, oleic, and linoleic acids. Campesterol and β-stosterols of wheat germ oils obtained by the cold press and supercritical CO2 extraction are the major sterols. The germ oil extracted by both methods contained 24.19% and 23.44 % campesterol and 60.98% and 61.56% β-stosterol, respectively. While germ oil obtained supercritical CO2 extraction contains 50.60% α-tocopherol and 49.39% β-tocopherol, the oil obtained by cold press contained 73.12% α-tocopherol and 26.83% β-tocopherol. Supercritical CO2 extraction is conducted for the process that must be decided whether the pilot or industrial scale. Supercritical CO2 extraction that high oil yield is very high investment costs.


Main Subjects

[1] de Vasconcelos M.C., Bennett R., Castro C., Cardoso P., Saavedra M.J., Rosa E.A., Study of Composition, Stabilization and Processing of Wheat Germ and Maize Industrial By-Products. Ind. Crops. Prod., 42: 292-298 (2013)
[2] Gomez A.M., de La Ossa E.M., Quality of Wheat Germ oil Extracted by Liquid and Supercritical carbon dioxide. J. Am. Oil Chem. Soc.,77(9): 969-974 (2000).
[3] Woerfel J.B., “Extraction” In: “Erickson D.R., editör, Practical Handbook of Soybean Processing and Utilization”, Champaign, IL: AOCS Press. p 65-92, (1995).
[4] Yu L., Zhou K., Parry J., Antioxidant Properties of Coldpressed Black Caraway, Carrot, Cranberry, and Hemp seed Oils, Food Chem., 91: 723–729 (2005).
[5] Crews  C, Hough P, Godward J, Brereton P, Lees  M, Guiet S., Quantitation of the Main Constituents of Some Authentic Grape-Seed Oils of Different Origin, J Agric Food Chem., 54: 6261–6265 (2006).
[6] Khosravi-Darani K., Vasheghani-Farahani E., Application of Supercritical Fluid Extraction in Biotechnology, Crit. Rev. Biotechnol.,25(4): 231-42 (2005).
[8] Khosravi-Darani K., Vasheghani-Farahani E., Yamini, Y., Solubility of Polyhydroxy Butyrate in Supercritical Carbon Dioxide, J. Chem. Eng. Data, 48: 860-863 (2003).
[9] Khosravi-Darani K., Vasheghani-Farahani E., Shojaosadati S.A., Yamini Y., The Effect of Process Variables on Supercritical Fluid Disruption of Ralstonia Eutropha Cells for Poly (hydroxybutyrate) Recovery, Biotechnol. Prog., 6: 1757-1765 (2004)
[10] Hartono R.,  Mansoori G.A., Suwono A., Prediction of Solubility of Biomolecules in Supercritical Solvents,  Chem. Eng. Sci., 56: 6949-6958 (2001).
[11] Nguyen, U., Evans, D.A., Frakman G., “Natural Antioxidants Produced by Supercritical Extraction. In: Supercritical Fluids Processing of Food and Biomaterials”, S.H. Rizvi, (Ed.), pp. (103-113), Chapman and Hall, ISBN 0751401846, Glasgow (1994).
[12] Crabas N., Marongiu B., Piras A., Pivetta T., Porcedda S., Extraction, Separation and Isolation of Volatiles and dyes from Calendula Officinalis L. and Aloysia Trphilla (L’Her) Britton by Süpercritical CO2, J. Essent. Res., 15: 272-277 (2003).
[13] Marongiu B., Piras A., Porcedda S., Comparative Analysis of the Oil and Süpercritical CO2 Extract of Elettaria cardamomum (L) Maton, J. Agric. Food Chem., 52: 6278-6282 (2004).
[14] Piras A., Rosa A., Falconieri D., Porcedda S., Dessì M.A., Marongiu B., Extraction of Oil from Wheat Germ by Supercritical CO2, Molecules, 14: 2573-2581 (2009).
[15] AOAC. “Official Methods of Analysis”, 15th edn. Association of Official Analytical Chemists, Washington, DC, (1990).
[16] Hişil Y., “Instrumental Analysis Techniques: (Eng. Fac. Publ. 55). Ege University, Bornova –İzmir, 1998. (in Turkish).
[18] Balz M., Schulte E., Their H.P., Trennung Von Tocopherolen und Tocotrienolen Durch HPLC, Fat. Sci. Technol., 94: 209-213 (1992).
[19] Firestone D., “Physical and Chemical Characteristics of Oils, Fats and Waxes”, AOCS Pres: Champaign, IL, p. 152, (1999).
[20] Eisenmenger M., “Superciritical Fluid Extractioni Fractionation, and Characterizataion of Wheat Germ Oil”, M.S Thesis, Oklahoma State University, Stillwater, OK, (2005).
[22] Irmak S., Dunford N.T., Policosanol Contents and Compositions of Wheat Varieties, J. Agric. Food Chem., 53: 5583-5586 (2005).
[23] Barnes P.J., Lipid Composition of Wheat Germ and Wheat Germ Oil, Fette Seifen Anstrichm, 84: 256-269 (1982).
[24] Dunford N.T., Zhang M.Q., Pressurized Solvent Extraction of Wheat Germ Oil, Food Res. Int., 36: 905-909 (2003).
[25] Wang T., Johnson L., Refining High-Free Fatty Acid Wheat Germ Oil, J. Am. Oil Chem. Soc., 78: 71-76 (2001).
[26] Gustone F.D., Harwood J.L., Padley F.B., “The Lipid Handbook”, 2nd ed. Chapman & Hall. Londonp, p. 130, (1994).
[27] Mistry B., Min D., Effects of Fatty Acids on Oxidative Stability of Soybean Oil, J. Food Sci., 52: 831-     (1987).
[28] Jiang S.T., Niu L., Optimization and Evaluation of Wheat Germ Oil Extracted by Süpercritical CO2, Grasas Y Aceites, 62(2): 181-189 (2011).
[29] Brandolini A., Hidalgo A., Wheat Germ: Not Only a By-Product, Int. J. Food Sci. Nutr., 63 (S1): 71-74 (2012).
[30] Shao P., Sun P., Ying Y., Response Surface Optimization of Wheat Germ Oil Yield by Süpercritical Carbon Dioxide Extraction, Food Bioprod. Process, 86: 227-231 (2008).
[31] Özcan M.M., Rosa A., Dessı M.A., Marongiu B., Piras A.,  AL-Juhaimi F.Y., Quality of Wheat Germ Oil Obtained by Cold Pressing and Supercritical Carbon Dioxide Extraction, Czech J. Food Sci., 31: 236–240 (2013).
[3]2 Dunford  N.T., Martinez J., “Nutritional Components of Supercritical Carbon Dioxide Extracted Wheat Germ Oil, Proceedings of 6th International Symposium on Supercritical Fluids”, April 28-30, Versailles, France. Vol. 1, Page: 273-278, (2004).
[33] Itoh T., Tamura T., Matsumoto T., Sterol Composition of 19 Vegetable Oils, J. Am. Oil Chem. Soc., 50(4): 122-125 (1973).
[34] Anderson R.J., Shriner R.L., Burr G.O., The Phytosterols of Wheat Germ Oil, J. Am. Oil Chem. Soc., 48: 2987-2996 (1926).
[35] Kiosseoglou B., Boskou D., On the Level of Esterified Sterols in Cotton Seed, Tomato Seed, Wheat Germ and Safflower, Oleagineux, 42: 169-170 (1987).
 [36] Traber M.G., Packer L., Vitamin E, Beyond Antioxidant Function, Am. J. Clin. Nutr., 62: 15015-15095 (1995).