# Spectroscopic Techniques Application for Wine and Wine Byproduct Authentication
## 5 Conclusions  
UV-Vis spectroscopy has been effectively applied in various contexts, including the authentication of wine vinegar, the determination of polyphenic compounds in red wines, and the geographical classification of wines. Combined with chemometric tools, this technique provides a rapid and cost-effective wine analysis and quality control method. MIR spectroscopy has been successfully applied to various wines, including red, white, fruit, and rice. It is used for varietal classification, quality control, and predicting chemical compositions and sensory properties. NIR spectroscopy has been effectively utilized for various wines, including wines from the Vinho Verde region and red wines, to quantify volatile and phenolic compounds, assess grape quality, classify wines based on aging processes, and measure elemental concentrations. Spectroscopy techniques offer a powerful and efficient approach for authenticating wine and wine byproducts, particularly when combined with chemometric methods. Their ability to rapidly and accurately assess quality parameters and verify authenticity makes them invaluable tools in the wine industry. Researchers and industry professionals can enhance data quality, improve predictive accuracy, and derive more reliable insights by employing statistical techniques in spectroscopic data analysis. From preprocessing methods that refine raw spectral data to advanced data modeling, these approaches ensure the robustness and interpretability of spectroscopy-based wine analysis. Given wine's socio-economic importance and byproducts, additional techniques and trends have been explored. These include DNA-based methods for identifying grape varieties, real-time PCR techniques, and stable isotope analysis for detecting fraud. However,caution is required, as isotopic analysis is limited by factors such as the need for a thorough understanding of the geochemical context, the influence of winemaking practices, and the precision of analytical methods. These limitations necessitate careful consideration and the use of complementary techniques to ensure accurate wine authentication. AI integration with analytical and statistical techniques has facilitated the creation of robust databases for detecting fraudulent practices in marketing wines and their byproducts. Conceptualization, T.P. and A.V. ; writing--original draft preparation, T.P., A.V., F.C. and E.C. ; writing--review and editing, T.P., A.V., F.C. and E.C. ; supervision, T.P. All authors have read and agreed to the published version of the manuscript. This work was supported by the National Funds by FCT--Portuguese Foundation for Science and Technology, under the projects UID/04033: Centro de Investigacao e de Tecnologias Agro-Ambienteis e Biologicas and LA/P/0126/2020, [[https://doi.org/10.54499/LA/P/0126/2020](https://doi.org/10.54499/LA/P/0126/2020)]([https://doi.org/10.54499/LA/P/0126/2020](https://doi.org/10.54499/LA/P/0126/2020)). This research was also funded by the Chemistry Research Centre-Vila Real--CQ-VR: UIDB/00616/2020 and UIDP/00616/2020, [[https://doi.org/10.54499/UIDP/00616/2020](https://doi.org/10.54499/UIDP/00616/2020)]([https://doi.org/10.54499/UIDP/00616/2020](https://doi.org/10.54499/UIDP/00616/2020)) and [[https://doi.org/10.54499/UIDB/00616/2020](https://doi.org/10.54499/UIDB/00616/2020)]([https://doi.org/10.54499/UIDB/00616/2020](https://doi.org/10.54499/UIDB/00616/2020)), and by the CEMAT/IST-ID-Center for Computational and Stochastic Mathematics: UIDB/04621/2020 and UIDP/04621/2020, [[https://doi.org/10.54499/UIDB/04621/2020](https://doi.org/10.54499/UIDB/04621/2020)]([https://doi.org/10.54499/UIDB/04621/2020](https://doi.org/10.54499/UIDB/04621/2020)). The authors would like to thank the Chemistry Research Centre-Vila Real (CQVR), CITAB/Innov4 Agro Center for Research and Technology in Agro-Environmental and Biological Sciences, the Institute for Innovation, Capacity Building, and Sustainability of Agri-Food Production, and CEMAT/IST-ID for their financial support. The authors declare no conflicts of interest.