High-Resolution Nuclear Magnetic Resonance Spectroscopy of Wine, Beer, and Spirits

This text aims at presenting an account of the use of high resolution ¹H and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy for the direct characterization of the composition of wine, beer, and spirits. This differs from the approach involved in the well established quality control method known as Site-specific Nuclear Isotope Fractionation (SNIF)-NMR, which usually involves ²H observation for the measurement of isotopic ratios and correlation with product origin and which is described in a separate entry of this handbook. The application of high resolution NMR to the complex food mixtures mentioned above aims at detecting as many compounds as possible, including minor components, not only giving a compositional overview of the food, but also allowing the unexpected to be detected in a number of possible situations (biochemical studies, adulterations, contaminations). A vast number of studies have used NMR to identify particular compounds in sample extracts following specific separation and concentration steps. In wine, phenolic compounds are still the class of compounds more extensively studied due to their role in wine characteristics as well as interesting antimicrobial and antioxidant properties. However, the intention of this text is to account preferably for studies involving the direct NMR analysis of whole samples, rather than of their extracts, except where otherwise specified.