Determination of inorganic tracers in agave plants and agricultural soils as an auxiliary parameter to ensure the authenticity of the region that grants the Denomination of Origin of Tequila

Abstract

To find authenticity parameters in agricultural soils belonging to the region that grants the Denomination of Origin of Tequila (DOT) 26 samples belonging to Jalisco (sub-regions: Valles, Altos Sur, Ciénega, Lagunas, and Sur), Michoacán, Nayarit, and, Sinaloa were characterized. The characterization consisted of determining texture, apparent density, color, pH, humidity, organic matter, total carbon, and trace metals analyzed by ICP-MS and X-ray fluorescence (XRF). The results obtained were studied through statistical analysis using a one-way ANOVA. For the case of apparent density (0.95 ± 0.10 g mL −1 ), pH (5.8 ± 1.13), humidity (11.29 ± 5.73%), organic matter (0.81 ± 0.18%) and total carbon (9.70 ± 2.45%), no significant differences were detected. Also, color characterization showed that Jalisco regions soils are mostly reddish, associated with mineralogical matrix composition. The characterization of metals by XRF shows that trace metals are associated with micro and macronutrients in soils. Finally, to achieve groups classification, ternary graph using a combination of Cr-Ba-Zr was constructed. The presence of these minerals is due to the DOT region is within the volcanic region of western Mexico. These metals migrate to the agave plant (3995 ± 1279 mg Ba g −1 , 75.75 ± 24.64 mg Cr g −1 , and 7.54 ± 4.67 mg Zr g −1 ) and remain in traces until final product (Tequila 100% agave silver-class, 5.34 ± 4.77 μg Ba L −1 , 13.3 ± 2.2 μg Cr L −1 ) being useful as auxiliary tracers to determine soil authenticity and agave belonging to DOT region. • Soils and plants from the Denomination of Origin of Tequila were characterized. • DOT regions soil properties provide inorganic tracers to the beverage. • Cr, V, Sr, Ba, and Zr traces are useful for classifying soil groups in the region. • Metals can be attributed to the mineralogy of the volcanic soils of the region. • Geochemical fingerprints can be useful as authenticity criteria for Tequila.