Chemical profiling and UHPLC-QToF analysis for the simultaneous determination of anthocyanins and flavonoids in Sambucus berries and authentication and detection of adulteration in elderberry dietary supplements using UHPLC-PDA-MS

Abstract

This work was initiated to develop a simple, quick, and reliable UHPLC-PDA-MS method to identify chemical markers for authentication and compare fruit samples of four elder species, Sambucus nigra, S. ebulus, S. canadensis, and S. cerulea. The UHPLC method showed an adequate separation of 11 compounds including anthocyanins, phenolic acids, and flavonoids in berries of the four Sambucus species. Quantification, detection limits, precision, accuracy as well as robustness were determined. The analysis of 55 different samples of four Sambucus species showed distinct phytochemical fingerprints. Thirty-one dietary supplements claiming to contain S. nigra berries extract were analyzed to determine authenticity. Ten (32%) of the 31 products complied with the label and contained only elderberry. The application of UHPLC-QToF provided useful information to characterize seventy-three compounds that can be used to distinguish among the four Sambucus species and also help to determine the presence of adulterants. Extracts of black rice (Oryza sativa) were identified as the main adulterants in the dietary supplements, although other undeclared ingredients such as extracts of purple carrot (Daucus carota ssp. sativus var. atrorubens) and flowers of S. nigra were also found instead of elder berry in two products. In addition to the detection of adulterated samples based on a comparison of the chemical profiles of anthocyanin and flavonoids, the developed methods can also be useful for the quality assessment of both bulk raw material and dietary supplements.