Application of Optical Spectroscopic Techniques and Multivariate Statistical Analysis as a Method of Determining the Percentage and Type of Adulteration of Extra Virgin Olive Oil

The adulteration of extra virgin olive oil (EVOO) with low quality edible oils is a major problem in the industry leading to economic frauds as well as customers' health issues. A number of techniques have been used in the recent years for the characterization of extra virgin olive oil adulteration. In the current work, the spectroscopic techniques of absorption and fluorescence in combination with statistical analysis have been exploited to classify and quantify the adulteration of EVOO with different seed oils and pomace oil. The specific spectroscopic methods are rapid, with low cost and no sample pretreatment is required. The results of the present work indicate that both techniques are suitable for olive oil quality control, with absorption at visible region (400-800 nm) being superior for the specific number and types of oil samples. Specifically, visible absorption spectroscopy presents adulteration detection limits below 10%, a percentage within the range of commercial interest. The model accuracy of classification for the mixtures of adulterated oils is above 90%. For the first time, we present a facile method for obtaining simultaneously the amount of adulteration and the type of the adulterant in EVOO.