Impact of the filtration process on the chromatographic, isotopic, and color profile of Tequila 100% Agave

Tequila is produced by fermenting and distilling juice extracted from the Agave tequilana Weber blue variety. The distillate can undergo a maturation process in wooden barrels, affecting its sensorial properties, particularly the amber color that is characteristic of aged spirits. However, several consumers have sought a product with the same profile as an aged, extra-aged, or ultra-aged class but without its characteristic color. This has been obtained through a selective filtration process (using activated carbon and cellulose filters) that allows the color to be removed without losing the aromatic profile; in this process, the product has been named Cristalino. In the present study, there are six sets of samples, each set divided into two groups, as follows: 1 (aged or extra-aged) and 2 (aged or extra-aged filtered: Cristalino). The samples were analyzed to evaluate their physicochemical profile. The analyses consisted of isotope ratio mass spectrometry, gas chromatography, liquid chromatography, UV–Visible spectroscopy, and color study using digital image processing. The results corroborated that the chromatographic profiles (mg/100 mL A.A.)—higher alcohols (293.40), methanol (202.05), esters (33.07), aldehydes (5.74), and furfural (0.67)—do not present statistically significant differences between groups (p>0.05). In the case of isotopic ratios, d¹³C_VPDB=13.07‰ and d¹⁸O_VSMOW=20.91‰ exhibited values that corroborate that the sugar source was from Agave tequilana Weber blue variety, and it is not affected in the filtration process. On the other hand, the UV–Vis spectra show two absorption bands at 280 and 365 nm, which are related to the total polyphenols and total flavonoids (found only in group 1). The high presence of flavonoids in an oxidizing medium results in the formation of complexes that give the characteristic amber color of aged beverages, which can be quantified from the values of the RGB color model. It was concluded that filtration selectively removes color while preserving the chromatographic profile, confirming that Tequila Cristalino is a Tequila 100% agave aged or extra-aged without color.