Fluorescence properties of plant anthocyanin pigments.: I.: Fluorescence of anthocyanins in Brassica oleracea L. extracts

The fluorescence of anthocyanin pigments in water extracts of Brassica oleracea L. (red cabbage) has been studied. The fluorescence spectra and fluorescence excitation spectra of pigments in starting extracts and in chromatographic fractions have been measured. It has been stated that the group of fluorescent anthocyanins (or other fluorescent species as well) exists in water extracts of red cabbage. Attempts to separate the fluorescence spectra, characteristic of these compounds, have been undertaken by choosing proper parameters for measurements of fluorescence spectra and fluorescence excitation spectra and deconvolution of registered fluorescence spectra. Three fluorescent species, ZI, ZII and ZIII, are distinguished. Their fluorescence spectra are centred at 363, 434 and 519 nm, respectively. It is suggested that fluorescence investigations, apart from the standard methods of visible absorption spectroscopy, may extend the possibilities of analysis and registration of the changes of anthocyanins in these extracts. (C) 1999 Elsevier Science S.A. All rights reserved.