Rapid analytical strategies for the identification of the botanical species of several "specialty" or "gourmet" oils

A comprehensive data collection of "authentic" cold-pressed industrial virgin oils was performed. Eight different botanical species, i.e. nuts, hazelnuts, almonds, apricot, avocado, sunflower, rosehip and rosa moschata plus olive were studied as the gold standard of cold-pressed virgin oils. Both organic and conventional supply chains were considered, as well as the different geographical origins and any preliminary steps carried out on raw materials (e.g. roasting). Two different analytical approaches are proposed to rapidly verify the botanical species of the origin of the oil-based raw material. The first approach is based on a multivariate statistical approach of conventional analytical data, namely their fatty acid composition. These data have been re-elaborated in a multivariate way by Principal Component Analysis (PCA) and classification methods. The second approach proposes a fast and non-destructive spectrophotometric analysis strategy to determine the color of these oils as a marker of their botanical authenticity. In this regard, the raw diffuse reflectance spectra (380-700 nm) obtained by a UV-Vis spectrophotometer with an integrating sphere is considered and elaborated by chemometrics. This information is compared with the results obtained by most common approach based on the CIELAB parameters.