ISO 21846:2018
(Main)Vegetable fats and oils — Determination of composition of triacylglycerols and composition and content of diacylglycerols by capillary gas chromatography
Vegetable fats and oils — Determination of composition of triacylglycerols and composition and content of diacylglycerols by capillary gas chromatography
This document specifies the determination of composition of triacylglycerols and the determination of the composition and content of diacylglycerols by capillary gas chromatography in vegetable oils with a lauric acid content below 1 %. Applying certain technological processing 1,2-diacylglycerols (1,2-DAGs) are transformed to the more stable isomeric 1,3-diacylglycerols (1,3-DAGs) due to acidic catalysed reaction. During storage, the speed and amount of this rearrangement depends on the acidity of the oil. The transformation normally reaches an equilibrium between the two isomeric forms. The relative amount of 1,2-DAGs is related to oil freshness or to a possible technological treatment. Therefore, it is possible to use the ratio of 1,2-DAGs to 1,3-DAGs as a quality criterion for vegetable fats and oils. The triacylglycerols profile is of potential interest for the fingerprint of each vegetable oil and may help the detection of certain types of adulteration, such as the addition of high oleic sunflower oil or palm olein in olive oil. NOTE This document is based on Reference [3].
Corps gras d'origine végétale — Détermination de la composition des triacylglycérols et de la teneur en diacylglycérols par chromatographie en phase gazeuse sur colonne capillaire, dans les huiles végétales
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 21846
First edition
2018-08
Vegetable fats and oils —
Determination of composition of
triacylglycerols and composition and
content of diacylglycerols by capillary
gas chromatography
Corps gras d'origine végétale — Détermination de la composition
des triacylglycérols et de la teneur en diacylglycérols par
chromatographie en phase gazeuse sur colonne capillaire, dans les
huiles végétales
Reference number
ISO 21846:2018(E)
©
ISO 2018
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ISO 21846:2018(E)
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ii © ISO 2018 – All rights reserved
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ISO 21846:2018(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Reagents . 2
7 Procedure. 3
7.1 Gas chromatographic apparatus and capillary column condition . 3
7.2 Choice of operating conditions . 3
7.3 Performance of the analysis . 3
7.4 Peak identification . 3
7.5 Determination of percentage content of each triacylglycerol class . 4
7.6 Determination of percentage content of each 1,2 diacylglycerol . 4
7.7 Determination of weight percentage total content of diacylglycerols . 4
8 Expression of results . 5
9 Precision of the method . 5
9.1 Repeatability, r .5
9.2 Reproducibility, R .
...
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