Exploratory analysis of commercial olive-based dietary supplements

During the production of olive oil an important amount of wastes are generated. In last few years, their reutilization via recovery of polyphenolic fraction has attracted an increasing attention. Currently, the market of olive-based dietary supplements is composed of a broad range of natural extracts claiming different health effects and often sold without a clear statement on their chemical composition. The aim of the present study was to characterize the chemical profiles of a range of different olive-based dietary supplements. Such products were analyzed via untargeted metabolomics, using liquid chromatography coupled to high-resolution mass spectrometry (Orbitrap LTQ-XL), in order to explore their composition. PCA revealed a clear separation of samples according to the type of product (first component, 40% variance) and also according to the part of the olive-plant used (17% variance). The first component clearly divided gemmotherapy products from the other ones. Most of phenolics were present in these products in lower concentration (or not present). The second component was the one that separated the products according to the part of the olive plant used in their formulation, the fruits from the leaves. A Student’s t-test was performed in order to select the putative biomarkers discriminating among the observed classes. Finally, most promising biomarkers were annotated, and the ones identified at level 1 were also quantified via HPLC Alliance DAD-QDa MS (Waters). The data produced with this study is suitable to support the unambiguous classification of the olive-based dietary supplements. Funding: Operational Plan “POFESR 2014/20” (Autonomous Province of Trento).