Abstract
A hexane-extracted crude soybean oil was degummed in a reactor by counter-currently contacting the oil with supercritical CO2 at 55 MPa at 70°C. The phosphorus content of the crude oil was reduced from 620 ppm to less than 5 ppm. Degummed feedstocks were fed (without further processing,i.e., bleaching) directly to a batch physical refining step consisting of simultaneous deacidification/deodorization (1 h @ 260°C and 1–3 mm Hg) with and without 100 ppm citric acid. Flavor and oxidative stability of the oils was evaluated on freshly deodorized oils both after accelerated storage at 60°C and after exposure to fluorescent light at 7500 lux. Supercritical CO2-processed oils were compared with a commercially refined/bleached soybean oil that was deodorized under the same conditions.
Flavor evaluations made on noncitrated oils showed that uncomplexed iron lowered initial flavor scores of both the unaged commercial control and the CO2-processed oils. Oils treated with .01% (100 ppm) citric acid had an initial flavor score about 1 unit higher and were more stable in accelerated storage tests than their uncitrated counterparts. Supercritical CO2-processed oil had equivalent flavor scores, both initially and after 60°C aging and light exposure as compared to the control soybean oil. Results showed that bleaching with absorbent clays may be eliminated by the supercritical CO2 counter-current processing step because considerable heat bleaching was observed during deacidification/deodorization. Colors of salad oils produced under above conditions typically ran 3Y 0.7R.
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References
Tandy, D.C., and W.J. McPherson,J. Am. Oil Chem. Soc. 61:1253 (1984).
Sullivan, F.E., Ibid.358 (1976).
Beal, R.E., E.B. Lancastar and O.L. Brekke, Ibid.619 (1956).
List, G.R., C.D. Evans, L.T. Black and T.L. Mounts, Ibid.275 (1978).
List, G.R., T.L. Mounts, K. Warner and A.J. Heakin, Ibid.277 (1978).
List, G.R., T.L. Mounts and A.J. Heakin, Ibid.280 (1978).
Hayes, L., and H. Wolff, Ibid.440 (1956).
Brafie, B.,Chem. Ind.:1152 (1958).
Ohlsen, R., and C. Svensson,J. Am. Oil Chem. Soc. 53:8 (1976).
Stahl, E.,Fette Seifen. Anstrichm. 84:444 (1982).
List, G.R., and J.A. Friedrich,J. Am. Oil Chem. Soc. 62:82 (1985).
Taniguichi, M., T. Tsuji, M. Shibata and T. Kobayashi,Agric. Biol. Chem. 49:2367 (1985).
Goodrum, J.W., and M.B. Kilgo,Enger. Agric. 6:265 (1987).
Eggers, R., and U. Sievers,J. Chem. Eng. Japan 22:641 (1989).
List, G.R., and J.P. Friedrich,J. Am. Oil Chem. Soc. 66:98 (1989).
List, G.R., J.P. Friedrich and J.W. King,Oil Mill Gazetteer 95:28 (1989).
Dakovic, S., J. Turkulov and E. Dimic,Fat Sci. Technol. 91:116 (1989).
Fors, S.M., and C.E. Eriksson,Lebensm. Wiss. Technol. 23:390 (1990).
Favati, F., J.W. King and M. Mazzanti,J. Am. Oil Chem. Soc. 68:422 (1991).
Eggers, R., and V.C. Wilp,Fat. Sci. Technol. 93:348 (1991).
Bitner, E.D., J.P. Friedrich and T.L. Mounts,J. Am. Oil Chem. Soc. 63:338 (1986).
Friedrich, J.P., G.R. List and G.F. Spencer, inSeventh International Conference on Jojoba and Its Uses, edited by A.R. Baldwin, American Oil Chemists’ Society, Champaign, 1989, pp. 165–173.
Schwab, A.W., and H.J. Dutton, Ibid.57 (1948).
Moulton, K.J., Ibid.302 (1989).
Official Methods and Recommended Practices of the American Oil Chemists’ Society, edited by D. Firestone, American Oil Chemists’ Society, Champaign, 1989.
Warner, K., E.N. Frankel and T.L. Mounts,J. Am. Oil Chem. Soc. 66:558 (1989).
Warner, K., inFlavor Chemistry of Fats and Oils, edited by D. Min and T. Smouse, American Oil Chemists’ Society, Champaign, 1985, pp. 207–222.
Warner, K.,Assessment of Fat and Oil Quality in Analysis of Fats, Oils and Lipoproteins, American Oil Chemists’ Society, Champaign, 1991, pp. 344–386.
Moser, H.A., C.D. Evans, J.C. Cowan and W.F. Kwolek,J. Am. Oil Chem. Soc. 42:30 (1965).
Friedrich, J.P., U.S. Patent 4,466,923 (1984).
Friedrich, J.P., G.R. List and A.J. Heakin,J. Am. Oil Chem. Soc. 50:288 (1982).
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List, G.R., King, J.W., Johnson, J.H. et al. Supercritical CO2 degumming and physical refining of soybean oil. J Am Oil Chem Soc 70, 473–476 (1993). https://doi.org/10.1007/BF02542578
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DOI: https://doi.org/10.1007/BF02542578