Improvement of Wine Quality: Tannin and Polymeric Pigment Chemistry

The task we are undertaking is fundamental. There is currently no quantitative method for determining tannin and pigmented tannin. It is not understood to what extent certain compounds contribute to the overall color of aged (> 2 years old) wine, nor the relative abundances of those compounds. Furthermore, there are many compounds that comprise the molecular basis of pigmented tannin whose structures are unknown. This investigation aims at using mass spectrometry as a tool for assessing the extent of color contribution due to these compounds, identifying new compounds, and providing a means of identifying the relative abundances for determining which compounds are most highly associated with quality parameters. Once we better understand the molecular basis of pigmented tannin we can provide tools for winemakers to improve the quality of their product. Pursuant to our goals for this year of the project we have (1a) identified many compounds by mass spectrometry which comprise the wine matrix, and many yet which have not been observed. Our FT-ICR experiment for determination of the relative abundance, depletion and accumulation of particular compounds (1b) will be performed in April with our collaborator Professor Nikolai Kuhnert at his laboratories and the Bruker research laboratories in Bremen Germany. Development of synthetic standards (2abc) is in progress as we are still assessing the appropriate standards to synthesize. We have defined the compound classes which comprise the majority of molecular peaks and will be performing further iterative fragmentation of these compounds to determine their structural characteristics in March with fellow anthocyanin researcher Professor Colin Kay at the University of East Anglia. All in all we are on track to accomplish our objectives and maintain pace for the upcoming year of data analysis and subsequent experimentation.