Anthocyanin Profiling Using UV-Vis Spectroscopy and Liquid Chromatography Mass Spectrometry

Abstract

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. 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. 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. 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. 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. This paper reviews the applications of UV-Vis spectroscopy and LC-MS for qualitative and quantitative analysis of anthocyanins.