Measurement of adulteration of olive oils by near‐infrared spectroscopy

TLDR

Authentication of olive oils is crucial due to their high value and health risks from seed‑oil adulteration. The study presents a near‑infrared spectroscopy method to predict adulteration levels in virgin and extra‑virgin olive oils with corn, sunflower, and raw olive residue oils. The method uses principal component analysis and simple calibration to classify adulterant type and detect adulteration presence. The approach achieved up to 98 % correct predictions overall and 75 % for adulterant type, indicating near‑infrared spectroscopy can serve as a quality‑control system, though further work is needed for accurate adulterant identification.

Abstract

Abstract Authentication of olive oils is of great importance, not only because they command a high price but also because of the health implications of adulteration with seed oils. A method for predicting the level of adulteration in a set of virgin and extra‐virgin olive oils adulterated with corn oil, sunflower oil, and raw olive residue oil by near‐infrared spectroscopy is presented. The best result was a correct prediction for 98% of the samples. Principal component analysis was used to predict the type of adulterant. The best result was a 75% prediction rate. From these results, it is concluded that it is possible to design a quality control system, which uses near‐infrared technology to measure the level of adulteration. In the case where the only test is whether the sample is adulterated or not, a simple calibration for adulteration can be used. The results suggest that principal component analysis may offer a means of identifying the adulterant, although more work is required to give an acceptable level of accuracy.