Fluorescence spectroscopy for grape and wine compositional analysis and quality control

Wine is an important global alcoholic beverage produced in many regions, in a wide array of styles, and from different grape varieties. Quality is an important concept for wine production, but that depends on the viewpoint (e.g., winemaker, novice consumer, expert), making it challenging to simply define the quality of wine and the grapes from which it originates. Based on extensive research, however, some consensus on the definition of quality is available, which helps underpin how to measure, evaluate, and control grape and wine quality using chemical and sensory methods. Recently, with the growing demand for simple, rapid, and cost-effective techniques to objectively evaluate the quality of grape, wine, and wine-derived spirits in the wine industry, novel spectroscopic technologies, used in conjunction with chemometrics, have been developed and implemented. Among these, fluorescence spectroscopy has shown advantages as an analytical tool in a number of aspects of grape and wine research and winemaking practice. This chapter provides an overview of the definition of grape and wine quality from different perspectives and summarizes commonly used methods for measurement, evaluation, and control of grape and wine quality after providing an understanding of the chemical components of importance. Finally, the chapter provides an update on the current progress of research and application of fluorescence spectroscopy combined with chemometrics and machine learning devoted to grape and wine analysis, including phenolic detection and prediction, grape maturity monitoring, wine classification, and authentication, among others.