Implementation of a carbon electrode-based sensor for monitoring the physicochemical quality in the production of Tequila Rosado

Abstract

Tequila Rosado, an innovative beverage whose main appeal is its pink hue, in some cases it can be prepared by infusing Tequila 100 % Agave Silver Class (T100%-SC) with Hibiscus Flowers (T100%-SC-HF) or aging in Wine Barrels (T100%-SC-WB). Given the impact of these processes on its physicochemical properties, it is essential to analyze its characteristics to ensure optimal quality. This study focuses on the electrochemical characterization of color in Tequila Rosado, using emerging analytical techniques to assess color variations based on production methods. While no statistically significant differences were found in the levels of methanol, higher alcohols, esters, aldehydes, furfural, δ¹³C_VPDB, and δ¹⁸O_VSMOW compared to Tequila 100 % Agave Silver Class, production processes significantly alter the color profile. Image analysis with RGB and HSV models showed an increase in red tones, generating shades of pink and beige. UV–Vis spectroscopy supports these findings, showing a band at 530 nm in T100%-SC-HF, associated with natural hibiscus pigments, and a band at 365 nm in T100%-SC-WB, typical of aged Tequilas. However, the most notable aspect is the use of electrochemical techniques, such as Differential Pulse Voltammetry (DPV), which allows precise evaluation of the color index. Electrochemical results show that color differences correlate with manufacturing processes, reflecting the oxidation signals of phenolic compounds, flavonoids, anthocyanins, and tannins present in hibiscus flowers and wine barrels. These electrochemical measurements provide a robust and emerging tool for characterizing the coloration in beverages like Tequila Rosado.