A Simple and Precise Detection of the Adulteration of Olive Oil with Hazelnut Oil Using Lawesson’s Reagent

Abstract

Adulteration of olive oil, particularly olive oil, with cheaper oil, such as hazelnut oil, is a common way of cheating the consumers, which makes detection of hazelnut oil in olive oil an important subject. In the current state of art, such detection is not possible, applying common analytical techniques such as High Performance Liquid Chromatography (HPLC), Gas Chromatography with Flame Ionization Detector (GC-FID), etc. This study presents a simple and precise method for the detection of hazelnut oil in olive oil through the reaction of Lawesson’s reagent (LR) with 5-methylhept-2-en-4-one (filbertone), known as a specific flavor compound in hazelnut oil and does not exist in other vegetable oils. The reaction produces a non-volatile, stable and UV visible compound, which is identified by HPLC equipped with UV-Vis detector (HPLC/UV-Vis) up to the sensitivity of 3.0% (w/w). This is a highly satisfactory limit for the detection of adulteration of olive oil with hazelnut oil. Application of the method is not limited with olive oil, could be applied to other oils.