Anthocyanin profiling using UV-vis spectroscopy and liquid chromatography mass spectrometry

Abstract

Background: As a powerful antioxidant and natural colorant, anthocyanins are being used increasingly as a component of food supplements and nutraceutical products. Hence, its characterization is a prerequisite for further exploration of its nutraceutical potential. UV-Vis and MS are the two important techniques, which have been largely employed for the qualitative and quantitative determination of anthocyanins. However, a comprehensive review of the applications of these techniques in literature is scarce. Objective: This paper aims to review the utilization of UV-Vis spectral data as well as mass spectral data for characterization and putative identification of anthocyanins with approaches of quantification. Methods: The techniques described in literature have been thoroughly reviewed and comparatively evaluated. The complementary approaches of UV-Vis and MS spectra have been discussed for identification and quantification of these compounds. Results: Valuable information about the chemical composition and structure of anthocyanins can be predicted from the UV-Vis spectral data, such as number and type of glycosylation as well as absence or presence of acylation, to name a few. It is also pointed out that for their structural confirmation, selectivity of mass detectors with unit and high-resolution analysis could be effective. Conclusions: The combination of LC-MS with UV-Vis spectroscopy provides complementary information on structural details of anthocyanins. In case the analytical reference standards are available, a triple quadrupole mass spectrometer provides selectivity and quantitative sensitivity in analysis. On the other hand, high-resolution MS analysis provides valuable information for tentative identification during nontarget screening of compounds when the reference standard is not available. Highlights: This paper reviews the applications of UV-Vis spectroscopy and LC-MS for qualitative and quantitative analysis of anthocyanins.