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Fatty acid and conjugated linoleic acid isomer profiles in human milk fat
Author(s) -
Luna Pilar,
Juárez Manuela,
de la Fuente Miguel Angel
Publication year - 2007
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.200700139
Subject(s) - chemistry , polyunsaturated fatty acid , conjugated linoleic acid , fatty acid , linoleic acid , cis–trans isomerism , oleic acid , high performance liquid chromatography , lactation , chromatography , food science , organic chemistry , biochemistry , biology , pregnancy , genetics
The fatty acid composition of 39 mature human milk samples from four Spanish women collected between 2 and 18 weeks during lactation was studied by gas chromatography. The conjugated linoleic acid (CLA) isomer profile was also determined by silver‐ion HPLC (Ag + ‐HPLC) with three columns in series. The major fatty acid fraction in milk lipids throughout lactation was represented by the monounsaturated fatty acids, with oleic acid being the predominant compound (36–49% of total fatty acids). The saturated fatty acid fraction represented more than 35% of the total fatty acids, and polyunsaturated fatty acids ranged on average between 10 and 13%. Mean values of total CLA varied from 0.12 to 0.15% of total fatty acids. The complex mixture of CLA isomers was separated by Ag + ‐HPLC. Rumenic acid (RA, cis ‐9 trans ‐11 C18:2) was the major isomer, representing more than 60% of total CLA. Trans ‐9 trans ‐11 and 7‐9 ( cis ‐ trans + trans ‐ cis ) C18:2 were the main CLA isomers after RA. Very small amounts of 8‐10 and 10‐12 C18:2 ( cis‐trans + trans‐cis ) isomers were detected, as were different proportions of cis ‐11 trans ‐13 and trans‐ 11 cis ‐13 C18:2. Although most of the isomers were present in all samples, their concentrations varied considerably.