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Supercritical carbon dioxide extraction of cottonseed with co‐solvents
Author(s) -
Kuk M. S.,
Hron R. J.
Publication year - 1994
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02541354
Subject(s) - gossypol , chemistry , supercritical carbon dioxide , cottonseed , extraction (chemistry) , hexane , chromatography , solvent , supercritical fluid , ethanol , carbon dioxide , fraction (chemistry) , supercritical fluid extraction , yield (engineering) , nuclear chemistry , organic chemistry , food science , materials science , biochemistry , metallurgy
Extraction of cottonseed lipids with supercritical carbon dioxide (SC‐CO 2 ) was conducted with and without a cosolvent, ethanol or 2‐propanol (IPA). At 7000 psi and 80°C, the reduced pressure, temperature and density of SC‐CO 2 was at 6.5, 1.17 and 1.85, respectively; the specific gravity was 0.87. Under these conditions, CO 2 is denser than most liquid extraction agents such as hexane, ethanol and IPA. The extraction of cottonseed with SC‐CO 2 gave a yield of more than 30% (moisture‐free basis). This is comparable to yields obtained by the more commonly used solvent, hexane. The crude cottonseed oil extracted by SC‐CO 2 was visually lighter than refined cottonseed oil. This was substantiated by colorimetric measurements. No gossypol was detected in the crude oil. However, crude oil extracted by SC‐CO 2 , to which less than 5% of ethanol or IPA as co‐solvent was added, contained ca. 200 ppm of gossypol, resulting in the typical dark color of cottonseed crude oil with gossypol. CO 2 extracted a small amount of cottonseed phosphatides, about one‐third of that extracted by pure ethanol, IPA or hexane. A second extraction with 100% ethanol or IPA after the initial SC‐CO 2 extraction produced a water‐soluble lipid fraction that contained a significant amount of gossypol, ranging between 1500 and 5000 ppm. Because pure gossypol is practically insoluble in water, this fraction is believed to be made up of gossypol complexed with polysaccharides and phosphatides.