Premium
Interference of polar lipids with the alkalimetric determination of free fatty acid in fish lipids
Author(s) -
Zhou Shengying,
Ackman Robert G.
Publication year - 1996
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/bf02523410
Subject(s) - chemistry , phospholipid , flame ionization detector , chromatography , fatty acid , titratable acid , gas chromatography , food science , biochemistry , membrane
An examination of the suitability of an alkalimetric method for the determination of free fatty acid (FFA) contents in fats, oils, and lipid extracts was conducted by comparing AOCS method Ca 5a‐40 with a method based on a Chromarod‐latroscan thin‐layer chromatography‐flame‐ionization detector (TLC‐FID) system. The FFA contents determined by the alkalimetric method were consistently higher than the genuine FFA contents obtained by the latroscan TLC‐FID method. Phospholipids were found to be the major components that contributed to the alkali‐titratable, nongenuine FFA in the total FFA determined alkalimetrically. Contributions from other polar lipid components were smaller, but they dominated as the proportion of phospholipids fell. The other alkali‐titratable polar components may include oxidized lipids and their by‐products bound to protein fragments. The accurate determination of FFA contents by alkalimetric methods may only be applicable to those commercially refined fats and oils that contain negligible amounts of phospholipids. Corrections for the alkalimetrically determined FFA contents should be made for those fats and oils with relatively high phospholipid contents by correlating the nongenuine FFA contents and the phospholipid contents.