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GC/EI‐MS Determination of the Diastereomer Distribution of Phytanic Acid in Food Samples
Author(s) -
Schröder Markus,
Vetter Walter
Publication year - 2011
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/s11746-010-1682-y
Subject(s) - phytanic acid , diastereomer , phytol , chemistry , food science , fatty acid , chromatography , stereochemistry , organic chemistry , biochemistry , peroxisome , gene
Phytanic acid (3,7,11,15‐tetramethylhexadecanoic acid) is a branched‐chain fatty acid, produced by bacteria by means of oxidation and biohydrogenation of the chlorophyll side chain phytol (3,7 R ,11 R ,15‐tetramethylhexadec‐2‐en‐1‐ol). The later reaction generates to a new stereogenic center on C‐3 which can be both 3 R ‐ or 3 S ‐configured. Thus, two diastereomers (3 S ,7 R ,11 R ,15‐ and 3 R ,7 R ,11 R ,15‐phytanic acid) are naturally produced. In this study we examined the diastereomer composition of phytanic acid in terrestrial and marine food samples. Phytanic acid was transferred into its methyl ester which was analyzed by GC/MS in the selected ion monitoring mode. The first eluted diastereomer in the samples was tentatively identified as 3 S ,7 R ,11 R ,15‐phytanic acid. The marine samples were clearly dominated by 3 S ,7 R ,11 R ,15‐phytanic acid whose abundance was higher in marine mammals than in fish. Milk from one organic cow collected over a period of 30 days showed lower proportions of 3 S ,7 R ,11 R ,15‐phytanic acid than milk from one cow raised with conventional feed. The difference between organic and conventional dairy products (cheese and butter) was not as pronounced as in milk. Milk samples from other mammals (goat, sheep, mare, camel, moose, and human) also showed an excess of 3 S ,7 R ,11 R ,15‐phytanic acid except for camel and moose milk.