Dihydrophytol and phytol isomers as marker substances for hydrogenated and refined vegetable oils. Issue 10 (13th June 2014)

• Record Type: Journal Article
• Authors: Schröder, Markus; Lehnert, Katja; Hammann, Simon; Vetter, Walter
• Is Part Of: European journal of lipid science and technology. Volume 116:Issue 10(2014:Oct.)
• Page Start: 1372
• Page End: 1380
• Publication Date: 2014-06-13
• Subjects: Oils and fats, Edible -- Periodicals; Lipids -- Periodicals; 660.63
• DOI: 10.1002/ejlt.201400095
• Languages: English
• ISSNs: 1438-7697

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="ejlt201400095-sec-0001" sec-type="section"> <p>Edible vegetable oils are an important part of the human diet. Products with different levels of processing are marketed for this purpose. Key‐products are virgin oils, refined oils, and partly or fully hydrogenated oils. In this study we explored whether compounds derived from <italic>trans</italic>‐phytol, i.e. the natural constituent of chlorophyll, could serve as marker compounds for identifying the processing type of oils, spreads and margarines. The evaluation was based on the contribution of the native <italic>trans</italic>‐phytol along with its transformation products <italic>cis</italic>‐ and <italic>iso</italic>‐phytol as well as dihydrophytol. Gas chromatography with mass spectrometry operated in the selected ion monitoring mode enabled the detection of these compounds at >0.01 mg/100 g oil or fat. In virgin vegetable oils <italic>trans</italic>‐phytol was the principle phytol related compound while <italic>cis</italic>‐phytol was generally <0.05% and <italic>iso</italic>‐phytol and dihydrophytol were not detected at all. Refined vegetable oils contained <italic>trans</italic>‐, <italic>cis</italic>‐, and <italic>iso</italic>‐phytol but no dihydrophytol. Partly and totally hydrogenated vegetable oils contained dihydrophytol if at least 5% hydrogenated fat were present in the oil. The occurrence of <italic>cis</italic>‐ and <italic>iso</italic>‐phytol in vegetable oils can be used as indicators for refined oils while the presence of dihydrophytol in vegetable oils is an indication for hydrogenation.</p> <p> <bold>Practical applications:</bold> The analysis of <italic>trans</italic>‐phytol, <italic>cis</italic>‐phytol, <italic>iso</italic>‐phytol, and dihydrophytol can be used in food control for oil authentication. In this context <italic>iso</italic>‐phytol can serve as an additional marker for refined vegetable oils and dihydrophytol as a marker for hydrogenated vegetable oils.</p> <p> <inline-graphic xlink:href="ark:/27927/pgh1fcj5sfs" content-type="ejlt201400095-gra-0001" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> </p> <p>Native vegetable oils are containing <italic>trans</italic>‐phytol in the unsaponifiable matter. During the refining of vegetable oils measurable amounts of <italic>cis</italic>‐phytol and <italic>iso</italic>‐phytol are formed from <italic>trans</italic>‐phytol. In addition, hydrogenation of oils leads to formation of dihydrophytol from <italic>trans</italic>‐phytol and <italic>cis</italic>‐phytol, and these four compounds can be used to authenticate different qualities of vegetable oils.</p> </sec> </abstract>