A novel fluorescent approach to monitor the evolution of anthocyanins and derivatives in red wine was developed. Some red table wines and Port wine with different vintage years were first tested aiming to determine the ideal fluorescent conditions. The fluorescence contribution of both monomeric and polymeric anthocyanins was studied by comparing their emission spectra. By measuring the F700/F560 ratio on different wine samples and applying an inverted exponential function it was possible to estimate the monomeric/polymeric anthocyanins absorbance ratio that is proportional to the relative content of the two classes of compounds. The methodology was further developed by using pure compounds representative of monomeric anthocyanins and anthocyanin-pyruvic acid adducts namely by using malvidin-3-O-glucoside and Vitisin A. A fluorescence excitation ratio (FER350/550) was considered for estimating the absorbance ratio between Vitisin A and malvidin-3-O-glucoside. Overall, this work aims to use fluorescence in order to monitor the evolution of anthocyanin derivatives and to distinguish them from their anthocyanin precursors, thereby allowing to monitor the evolution of anthocyanin pigments during wine ageing but it also may be useful to determine age markers, or even geographical markers.
A fluorescent approach for measuring anthocyanins and derived prigments in red wine
Giovanni Agati;Paolo Matteini;
2013
Abstract
A novel fluorescent approach to monitor the evolution of anthocyanins and derivatives in red wine was developed. Some red table wines and Port wine with different vintage years were first tested aiming to determine the ideal fluorescent conditions. The fluorescence contribution of both monomeric and polymeric anthocyanins was studied by comparing their emission spectra. By measuring the F700/F560 ratio on different wine samples and applying an inverted exponential function it was possible to estimate the monomeric/polymeric anthocyanins absorbance ratio that is proportional to the relative content of the two classes of compounds. The methodology was further developed by using pure compounds representative of monomeric anthocyanins and anthocyanin-pyruvic acid adducts namely by using malvidin-3-O-glucoside and Vitisin A. A fluorescence excitation ratio (FER350/550) was considered for estimating the absorbance ratio between Vitisin A and malvidin-3-O-glucoside. Overall, this work aims to use fluorescence in order to monitor the evolution of anthocyanin derivatives and to distinguish them from their anthocyanin precursors, thereby allowing to monitor the evolution of anthocyanin pigments during wine ageing but it also may be useful to determine age markers, or even geographical markers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
