Protected geographical identification of honey by spark discharge-assisted laser-induced breakdown spectroscopy (LIBS)

Abstract

Honey is a natural food that is valued worldwide for its nutritional and therapeutic values. Therefore, authentication of honey based on geographical origin is a guarantee of its genuine properties of honey. In this article, an evaluation of spark discharge-assisted laser-induced breakdown spectroscopy (SD-LIBS) for certification of the geographical origin of honey is reported. Forty-nine samples of multifloral honey produced in four Argentine provinces were considered. The results showed that best classification performance was obtained using smoothing, generalized least squares weighting (GLSW) and mean centering for spectral preprocessing, added to the k-nearest neighbor (k-NN) or Support Vector Machine (SVM) classification algorithms, which provided 100% of correct classification. More importantly, the results of Partial Least Squares -Discriminant Analysis (PLS-DA) pointed to N, Ca, K, Cu, Fe and Mn as key elements for the certification of geographical origin. In addition, the best indicator for verification of the source of honey was found to be in the assessment of the amount of N in honey. These findings confirm SD-LIBS as a promising tool for authentication of honey origin and quality, providing a simple, fast and environmentally friendly solution. The method can be useful for industry, the marketplace and other areas related to food authentication.

The effects of cavity diameter and material type of spatial confinement on intensity of laser-induced breakdown spectroscopy

“…However, there are some key issues remaining unsolved, such as low detection sensitivity and low limit of detection. In order to tackle these problems, many methods have been proposed, including magnetic confinement [6,7], spatial confinement [8,9], spark discharge [10][11][12], double-pulse LIBS [13,14] and fs-LIBS [15]. Among these methods, the spatial limitation stands out by its own advantages, since it does not need any sophisticated equipment and also may be reproducible and repetitive.…”