Laser diode detects counterfeit olive oil
Researchers at the Complutense University of Madrid (UCM) and the Scintillon Institute in the U.S. have designed a sensor that can detect counterfeit olive oil labeled as extra virgin or protected designation of origin.
The tool, reported in Talanta, can distinguish between apparently similar oils that present notable differences in quality. This is possible thanks to the use of laser diodes, because the fluorescence emitted by adulterated oils is slightly different to that of pure extra virgin olive oils.
The tool is inexpensive both to use and to manufacture (with a 3-D printer). "Other clear advantages of our tool include the possibility of conducting on-site analyses, as the equipment is the size of a briefcase. And it generates results in real time," said José S. Torrecilla, a senior lecturer and researcher in the Department of Chemical Engineering and Materials at the UCM.
The tool offers the olive oil sector a means to tackle an expensive problem. "The quality of olive oil is recognised nationally and internationally. It is therefore necessary to protect this quality and combat fraudulent activities carried out with increasing frequency and skill in the sector," the UCM researcher continued.
Analysis using chaotic algorithms
To conduct the study, researchers mixed single-varietal oils of protected designation of origin with other protected designation of origin oils that were past their "best before" date. All the oils were purchased from grocery stores.
Subsequently, mixtures were made using oils with between 1 and 17 percent acidity that were also past their "best before" date. Lastly, measurements were performed using the sensor, which was manufactured via 3-D printing, and the results were analyzed using chaotic algorithms.
"This technique is available for use at any time, and only requires oils prior to packaging for quality control or after packaging to detect fraudulent brands and/or producers," concluded the UCM researcher.