The effect of adding hydroxycinnamic acids (caffeic acid, sinapic acid, p-coumaric acid and chlorogenic acid) in Cabernet Sauvignon dry red wine before and after fermentation was investigated, taking into account the color parameters, anthocyanin content, and overall polyphenol levels in the wine samples. The copigmentation effect of malvidin-3-O-glucoside and sinapic acid was further explored in model solution and through theoretical calculations. The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid (before the fermentation) showing the most pronounced color protection effect. Compared to control samples, the addition of hydroxycinnamic acids resulted in a 36% increase in total phenolic content and a 28% increase in total anthocyanin content. Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic. Theoretical studies identified hydrogen bonding (HB) and dispersion forces as the main primary stabilizing forces, with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.

Wine is a complex solution system generated by physical, chemical and biological transformation of grape berries. Traditional methods for wine authenticity identification and quality control are cumbersome and time-consuming, and therefore cannot meet the needs of mass production. Spectroscopic techniques can simplify the procedure of wine analysis, shorten the analysis time, and enable simultaneous analysis of multiple components. Therefore, spectroscopic techniques have been widely used to assess wine quality and identify the geographical origin, variety, age and authenticity of wine. Furthermore, the combination of spectroscopic techniques and chemometrics allows the identification or modeling of key chemical markers, providing rapid, accurate, non-destructive and real-time detection for wine analysis and quality control. In this article, we summarize the theoretical basis for the application of ultraviolet-visible (UV-Vis), infrared, fluorescence and Raman spectroscopy for wine analysis. Furthermore, we review the current status of the application of spectroscopic techniques in conjunction with chemometrics for wine traceability, quality control and authenticity identification. Finally, we discuss the challenges that spectroscopic techniques face when applied in practice and propose possible solutions to these challenges.