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Laser Induced Breakdown Spectroscopy (LIBS) is a technique that can provide fast multi-elemental analysis , and hence food authenticity “fingerprints”, without requiring any sample preparation. It is an under-utilized technology in the food sector because of its high setup cost and lack of LIBS expertise in this sector.

This review (subscription required) gives an outline of LIBS fundamentals and instrumentation alongside published scope and capabilities of LIBS for detecting adulteration in various food samples.  The authors consider that LIBS is a pre-existing tool within the authenticity testing armoury which could be better utilised in the food sector..

In this paper (open access) two optical spectroscopic techniques,  Laser-Induced Breakdown Spectroscopy (LIBS) and UV-Vis-NIR absorption spectroscopy, are assessed for EVOO adulteration detection, using the same reference database of olive oil samples. In total, 184 samples were studied, including 40 EVOOs and 144 binary mixtures with pomace, soybean, corn, and sunflower oils, at various concentrations (ranging from 10 to 90% w/w). The reference class of “pure” EVOOs were limited to oils from a specific geographic region (either Crete, Lesvos, Kalamata or Achaia, with a different model built for each case).

The emission data from LIBS, related to the elemental composition of the samples, and the UV-Vis-NIR absorption spectra, related to the organic ingredients content, were analyzed, both separately and combined (i.e., fused), by Linear Discriminant Analysis (LDA), Support Vector Machines (SVMs), and Logistic Regression (LR). In all cases, very highly predictive accuracies were achieved, attaining, in some cases, 100%.

The authors conclude that both techniques have the potential for efficient and accurate olive oil verification test protocols, with the LIBS technique being better suited as it can operate much faster.