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Concerns for the determination of free fatty acid in cottonseed
Author(s) -
Wan P. J.,
Pakarinen D. R.,
Wakelyn P. J.
Publication year - 1998
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/s11746-998-0178-5
Subject(s) - cottonseed , chromatography , chemistry , petroleum ether , cottonseed oil , extraction (chemistry) , saponification , fatty acid , hexane , extractor , solvent , food science , organic chemistry , engineering , process engineering
The official AOCS method for the determination of free fatty acid (FFA) in cottonseed requires dehulling the seed, grinding the meats with a 12‐blade food processor, and extracting the ground meats in a butt tube with three portions of room‐temperature petroleum ether. The extracted oil, after desolventization, is then titrated with NaOH to the end point of phenolphthalein in a mixed solvent of isopropanol and hexane. Our study showed that this procedure tends to underestimate the amount of FFA present in the oil of cottonseed by as much as 11.5%. It was also found that to obtain consistent and accurate FFA content, a desirable particle size is smaller than 10 mesh (preferably <14 mesh), minimum extraction temperature should be no less than 40°C (preferably greater than 50°C), and the extraction time should be longer than 2 h in a Soxhlet extractor.