Spectroscopic and Thermal Characterization of Extra Virgin Olive Oil Adulterated with Edible Oils

Abstract

The substitution of extra virgin olive oil with other edible oils is the primary method for fraud in the olive-oil industry. Developing inexpensive analytical methods for confirming the quality and authenticity of olive oils is a major strategy towards combatting food fraud. Current methods used to detect such adulterations require complicated time- and resource-intensive preparation steps. In this work, a comparative study incorporating Raman and infrared spectroscopies, photoluminescence, and thermal-conductivity measurements of different sets of adulterated olive oils is presented. The potential of each characterization technique to detect traces of adulteration in extra virgin olive oils is evaluated. Concentrations of adulterant on the order of 5% can be detected in the Raman, infrared, and photoluminescence spectra. Small changes in thermal conductivity were also found for varying amounts of adulterants. While each of these techniques may individually be unable to identify impurity adulterants, the combination of these techniques together provides a holistic approach to validate the purity and authenticity of olive oils.

Innovative Application of SERS in Food Quality and Safety: A Brief Review of Recent Trends

“…Two strategies to judge authenticity include: (1) combination with chemometrics to achieve the identification and quantification of food samples; (2) combination with specific target DNA-modified SERS substrates with a target-responsive Raman dye that can recognize the target ( Table 7 ) [ 58 , 59 ]. The SERS biosensors are regarded as a universal platform for the on-site determination of food quality, authenticity, and safety [ 60 ].…”

Advances in Spectrometric Techniques in Food Analysis and Authentication

“…In this Special Issue, Gajek and collaborators [1,2] have shown how the combination of chemometrics with ICP-MS data can be used to authenticate whisky samples. Chavez-Angel and collaborators have also described how vibrational spectroscopy (e.g., Raman and infrared) and thermal analysis can be combined to authenticate extra virgin olive oil [3]. The classification of coffee samples was also reported by combining both NIR and MIR spectroscopy with chemometric methods [4].…”