Raman Spectroscopic Detection of Olive Oil Adulteration

Olive oil is among the most commonly adulterated food products. Raman spectroscopy has the potential to be utilized in measurements of olive oil to establish purity from adulteration with other, less expensive, oils. This application note reviews some of the most compelling data present in recent scientific literature to support this claim. Background and Motivation Extra‐virgin olive oil is in high demand, and as a result commands high prices. Due to this fact, adulterated olive oil is reported to be the biggest source of agricultural fraud in Europe. It has been estimated that while less than 10% of the world olive oil production meets the criteria for being labeled as extra‐virgin, about 50% is thusly labeled.1 This is a problem, both from the perspective of label fraud, but also in terms of the health impacts of the product. Olive oil has recently been found to have significant health benefits, benefits that will not be received as expected if the oil has been adulterated or mixed with other oils. Further, some fraudulent oil has been discovered to be toxic.2 A significant percentage of fatty acids found in olive oil are monounsaturated. According to nutritionists, this type of fatty acids may help lower risk of heart disease by improving related risk factors; monounsaturated fatty acids have been found to lower total cholesterol and low‐density lipoprotein cholesterol levels. They may also help normalize blood clotting. Recent research shows that monounsaturated fatty acids may also improve insulin levels and blood sugar regulation.3 Quality control of edible oils is currently performed with instruments inside the analytical laboratory. Among the most commonly used techniques to perform QC and adulteration detection of oils are gas chromatography (GC), gas chromatography mass spectrometry (GCMS) and high‐performance liquid chromatography (HPLC)4‐7. In order for oil analysis to