Review of the use of phytosterols as a detection tool for adulteration of olive oil with hazelnut oil.
Adulteration of virgin olive oil with less expensive oils such as hazelnut oil is a serious problem for quality control of olive oil. Detection of the presence of hazelnut oil in olive oil at low percentages (<20%) is limited with current official standard methods. In this review, various classes of phytosterols in these two oils are assessed as possible markers to detect adulterated olive oil. The composition of 4-desmethyl- and 4-monomethylsterols is similar in both oils, but the 4,4'-dimethylsterols differ. Lupeol and an unknown (lupane skeleton) compound from 4,4'-dimethylsterols are exclusively present in hazelnut oil and can be used as markers via GC-MS monitoring to detect adulteration at levels as low as 2%. The phytosterol classes need to be separated and enriched by a preparative method prior to analysis by GC or GC/MS; these SPE and TLC methods are also described in this review.
Azadmard-Damirchi
Sodeif
S
Department of Food Science and Technology, University of Tabriz, Tabriz, Iran. azadmardd@yahoo.com
D002855:Chromatography, Thin Layer; D031211:Corylus / Q000737:chemistry*; D004042:Dietary Fats, Unsaturated / Q000032:analysis* / Q000592:standards; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D000069463:Olive Oil; D053978:Pentacyclic Triterpenes / Q000032:analysis; D010840:Phytosterols / Q000032:analysis* / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification; D010938:Plant Oils / Q000737:chemistry* / Q000592:standards; D011786:Quality Control; D052616:Solid Phase Extraction; D000094042:Lupanes
D004042:Dietary Fats, Unsaturated; D000069463:Olive Oil; D053978:Pentacyclic Triterpenes; D010840:Phytosterols; D010938:Plant Oils; C010480:lupeol; D000094042:Lupanes