Proučavanje efekta pH na strukturu, boju i spektralne karakteristike cijanidina i cijanidin 3-0-ß-glukopiranozida i ispitivanje njihove interakcije sa modelima lipidnih membrana

The relationships between structure, spectral characteristics, and colour of the aglycone moiety of cyanidin and its 3-glucosidic substitution in cyanidin 3-O- β-glucopyranoside were studied as a function of pH, using a combination of techniques (UV-Vis spectrophotometry, colorimetry, and HPLC-ESI/MS). The absorption and fluorescence emission spectra of cyanidin and Cy3Glc at pH 5.5 in aqueous solution have been studied. The colour variation, colour intensity and stability at various pH values (2.0, 4.0, 7.0 and 9.0) of cyanidin and Cy3Glc were investigated during a period of 8 hours storage at 25 ± 0.1ºC, as well as, in the aqueous solution at pH 7.0 and under the conditions of the elevated temperature (55.0 ± 0.1ºC) which simulate the rapid food ageing. The interactions of cyanidin and Cy3Glc with model lipid membranes differing in surface charge and phase state were investigated using DSC and fluorescence emission polarization spectrometry.