Laser Diodes in Sensor Detect Quality Differences in Olive Oils

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MADRID, Dec. 26, 2018 — Researchers at the Complutense University of Madrid (UCM) and the Scintillon Institute have designed a sensor that can detect counterfeit olive oil labeled as extra virgin or protected designation of origin. Laser diodes in the sensor detect fluorescence levels in the oils, which differ slightly between the adulterated and pure extra virgin olive oils.

To test the system, over 450 binary blends composed of protected designation of origin extra virgin olive oil (PDO EVOO) in date were adulterated with expired PDO EVOO and analyzed using fluorescence spectroscopy. The researchers measured the fluorescence emission of each sample using a laser diode as a source light and calculated 20 chaotic parameters from the resulting spectra. They quantified the concentration of adulterant using chaotic-based regression models. The researchers validated their approach according to the leave-one-out cross-validation method. The results were promising (lower than 10 percent quantification error).

Laser diodes in sensor detect differences in olive oil.
he sensor can distinguish between apparently similar oils. Courtesy of Esencia Andalusí.

The sensor is manufactured on a 3D printer and is inexpensive to build. “Other clear advantages of our tool include the possibility of conducting on-site analyses, because the equipment is the size of a briefcase and therefore portable, and of generating results in real time,” said researcher José S. Torrecilla.

The sensor could provide inexpensive quality control and adulteration detection for PDO EVOO. “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,” Torrecilla said.

The research was published in Talanta (

Published: December 2018
Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other electromagnetic radiation. Specifically, fluorescence involves the absorption of light at one wavelength and the subsequent re-emission of light at a longer wavelength. The emitted light occurs almost instantaneously and ceases when the excitation light source is removed. Key characteristics of fluorescence include: Excitation and emission wavelengths: Fluorescent materials...
fluorescence spectroscopy
The spectroscopic study of radiation emitted by the process of fluorescence.
Research & TechnologyeducationComplutense University of MadridScintillon InstituteEuropeAmericasspectroscopyLasersfluorescencefluorescence spectroscopyTest & MeasurementSensors & Detectorsdiode lasersConsumerindustrialagriculture

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