Determination of Tequila Quality by Photoacoustic Analysis

Isotopic Characterization of 100% Agave Tequila (Silver, Aged and Extra-Aged Class) for Its Use as an Additional Parameter in the Determination of the Authenticity of the Beverage Maturation Time

“…To solve the problems of adulteration and counterfeiting of the beverage, numerous research groups have focused their efforts to propose analytical techniques such as profiles of volatile organic compounds [ 3 ], gas chromatography-olfactometry [ 4 ], analysis by near-infrared spectroscopy (NIR-SIMCA) [ 5 ], solid-phase micro extraction- chromatography-mass spectrometry (SPME-GC-MS) [ 6 ], stable isotope evaluation [ 7 ], fractionation of natural isotopes of the specific site studied by nuclear magnetic resonance (SNIF-NMR) [ 8 ], solid-phase microextraction (SPME) [ 9 , 10 , 11 ], infrared spectroscopy by Fourier transform (FTIR) [ 12 , 13 ], chemometric studies and spectroscopic techniques [ 14 ], studies using photo-acoustic [ 15 ], studies using surface plasmon resonance [ 16 ], fluorescence spectroscopy [ 17 ], and through pattern recognition and supervised classification [ 18 ]. That can possibly use as an additional criterion for the 100% agave tequila silver class’s authenticity.…”

Authentication of tequilas using pattern recognition and supervised classification

“…Thus, UV-Vis [39], [40], [41], FTIR (medium region) [35], [42], and Raman [43] spectrometry, as well as chemiluminiscence [44] were applied to fight against tequila counterfeiting. Less frequent techniques are fluorescence spectroscopy (for which a portable UV fluorescence device was tested recently as a proof-ofconcept to discriminate fake tequila from genuine ones) [45], [46] and photoacoustics [47].…”

“…The chemometric algorithms applied to differentiate between types of tequila, original and fake tequilas, or to discriminate tequila from other products were diverse. They ranged in complexity from simple Student's t-tests to evaluate differences on: i) total phenolics, syringic, vanillic and protocatechuic acids between white and aged tequilas [5]; ii) biomass, reducing sugar and ethanol [16]; and iii) contents of ethyl carbamate [23]; correlation analysis to identify groups of samples from the same commercial brand [47], and ANOVA (analysis of variance) to determine differences between a set of production characteristics [16], [20], [27], [49] and ethyl carbamate in several beverages [23], to multivariate analyses. The latter include several approaches; namely: i) Principal components analysis (PCA) to differentiate amongst types of tequilas [20], [29], [33], [35], [39], [41], [43], to find groups of tequilas and mezcal (a beverage obtained from another type of Agave) [40], to evaluate the maturation of tequila in barrels [27] (they differentiated white, aged and ripened transition tequilas during maturation), to differentiate brands of rested tequilas [50] or to evaluate ethanol in tequilas [43].…”

A Sensor-Based Methodology to Differentiate Pure and Mixed White Tequilas Based on Fused Infrared Spectra and Multivariate Data Treatment

“…In Mexico alone, Tequila distillers estimated that ca. 40-50% of Tequila sales were adulterated, yielding an economic loss of about US $0.55 billion (equivalent to 60 million liters) [12]. Various types of counterfeit are common, such as the addition of water, alcohol, colorants, and aromas to the original beverages, even under poor hygienic conditions, leading to potential risks associated to their consumption.…”