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Mercedes Lopez - One of the best experts on this subject based on the ideXlab platform.
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quantification of selected volatile constituents and anions in mexican agave spirits Tequila mezcal sotol bacanora
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Dirk W. Lachenmeier, Evamaria Sohnius, Rainer Attig, Mercedes LopezAbstract:A large collection (n ) 95) of Mexican Agave spirits with protected appellations of origin (Tequila, Mezcal, Sotol, and Bacanora) was analyzed using ion and gas chromatography. Because of their production from oxalate-containing plant material, all Agave spirits contained significant concentrations of oxalate (0.1-9.7 mg/L). The two Tequila categories (“100% Agave” and “mixed”) showed differences in the methanol, 2-/3-methyl-1-butanol, and 2-phenylethanol concentrations with lower concentrations in the mixed category. Mezcal showed no significant differences in any of the evaluated parameters that would allow a classification. Sotol showed higher nitrate concentrations and lower 2-/3-methyl1-butanol concentrations. Bacanora was characterized by exceptionally high acetaldehyde concentrations and a relatively low ethyl lactate content. The methanol content was the most problematic compound regarding the Mexican standards: two Tequilas (4%), five Sotols (31%), and six Bacanoras (46%) had levels above the maximum methanol content of 300 g/hL of alcohol. In conclusion, the composition of Mexican Agave spirits was found to vary over a relatively large range.
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characterization of volatile compounds of mezcal an ethnic alcoholic beverage obtained from agave salmiana
Journal of Agricultural and Food Chemistry, 2006Co-Authors: A De Leonrodriguez, Pilar Escalanteminakata, Lidia Gonzalezhernandez, Ana Barba P De La Rosa, Mercedes LopezAbstract:Commercial mezcals (white, white with worm, rested, rested with worm, and aged) produced from Agave salmiana were analyzed by solid-phase microextraction−gas chromatography−mass spectrometry (SPME−GC−MS). Thirty-seven compounds were identified, and nine of them were classified as major compounds of mezcal (MCM). Saturated alcohols, ethyl acetate, ethyl 2-hydroxypropanoate, and acetic acid form the MCM group. Minor compounds of mezcal group include other alcohols, aldehydes, ketones, large chain ethyl esters, organic acids, furans, terpenes, alkenes, and alkynes. Most of the compounds found in mezcals in this study are similar to those present in Tequilas and other alcoholic beverages. However, mezcals contain unique compounds such as limonene and pentyl butanoate, which can be used as markers for the authenticity of mezcal produced from A. salmiana. Keywords: Mezcal; Agave; Tequila; ethanol; SPME; terpenes; alcohols
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Multivariate Analysis of FTIR and Ion Chromatographic Data for the Quality Control of Tequila
Journal of agricultural and food chemistry, 2005Co-Authors: Dirk W. Lachenmeier, Mercedes Lopez, Elke Richling, Willi Frank, Peter SchreierAbstract:Principal component analysis (PCA) was applied to the chromatographic and spectroscopic data of authentic Mexican Tequilas (n = 14) and commercially available samples purchased in Mexico and Germany (n = 24). The scores scatter plot of the first two principal components (PC) of the anions chloride, nitrate, sulfate, acetate, and oxalate accounting for 78% of the variability allowed a classification between Tequilas bottled in Mexico and overseas; however, no discrimination between Tequila categories was possible. Mexican products had a significantly (p = 0.0014) lower inorganic anion concentration (range = 1.5−5.1 mg/L; mean = 2.5 mg/L) than the products bottled in the importing countries (range = 3.3−62.6 mg/L; mean = 26.3 mg/L). FTIR allowed a rapid screening of density and ethanol as well as the volatile compounds methanol, ethyl acetate, propanol-1, isobutanol, and 2-/3-methyl-1-butanol using partial least-squares regression (precisions = 5.3−29.3%). Using PCA of the volatile compounds, a differentiat...
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Authentication of Tequila by gas chromatography and stable isotope ratio analyses
European Food Research and Technology, 2003Co-Authors: C. Bauer-christoph, Mercedes Lopez, N. Christoph, B. O. Aguilar-cisneros, Elke Richling, A. Rossmann, Peter SchreierAbstract:Gas chromatographic (GC) determination of volatile constituents and isotope ratio mass spectrometry (IRMS) analysis of 13C/12C isotope ratios as well as SNIF-NMR analysis of (D/H)-ratios of ethanol in authentic (n=12) and commercial Tequila samples (n=13) were used to differentiate analytically between Tequila derived from 100% agave (Agave Tequilana Weber var. Azul) and Tequila produced with other fermentable sugars ('mixed' Tequila). Evaluating the correlation of methanol and 2-/3-methyl-1-butanol concentrations, GC analysis was found to be a suitable method for the authenticity assessment of '100% agave' and 'mixed' Tequilas. Additional determinations of δ13CVPDB and (D/H) ratios of ethanol were used to show the perspectives and limits of the methods.
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Tequila authenticity assessment by headspace spme hrgc irms analysis of 13c 12c and 18o 16o ratios of ethanol
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Blanca O Aguilarcisneros, Mercedes Lopez, Elke Richling, Frank Heckel, Peter SchreierAbstract:By use of headspace SPME sampling and a PLOT column, on-line capillary gas chromatography−isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the δ13CVPDB and δ18OVSMOW values of ethanol in authentic (n = 14) and commercial Tequila samples (n = 15) as well as a number of other spirits (n = 23). Whereas with δ13CVPDB values ranging from −12.1 to −13.2‰ and from −12.5 to −14.8‰ similar variations were found for 100% agave and mixed Tequilas, respectively, the δ18OVSMOW data differed slightly within these categories: ranges from +22.1 to +22.8‰ and +20.8 to +21.7‰ were determined for both the authentic 100% agave and mixed products, respectively. The data recorded for commercial Tequilas were less homogeneous; δ13CVPDB data from −10.6 to −13.9‰ and δ18OVSMOW values from +15.5 to +22.7‰ were determined in Tequilas of both categories. Owing to overlapping data, attempts to differentiate between white, rested, and aged Tequilas within each...
Hugo Delgado-granados - One of the best experts on this subject based on the ideXlab platform.
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The eruptive history of the Tequila volcanic field, western Mexico: ages, volumes, and relative proportions of lava types
Bulletin of Volcanology, 2005Co-Authors: Catherine B. Lewis-kenedi, Rebecca A. Lange, Chris M. Hall, Hugo Delgado-granadosAbstract:The eruptive history of the Tequila volcanic field (1600 km^2) in the western Trans-Mexican Volcanic Belt is based on ^40Ar/^39Ar chronology and volume estimates for eruptive units younger than 1 Ma. Ages are reported for 49 volcanic units, including Volcán Tequila (an andesitic stratovolcano) and peripheral domes, flows, and scoria cones. Volumes of volcanic units ≤1 Ma were obtained with the aid of field mapping, ortho aerial photographs, digital elevation models (DEMs), and ArcGIS software. Between 1120 and 200 kyrs ago, a bimodal distribution of rhyolite (~35 km^3) and high-Ti basalt (~39 km^3) dominated the volcanic field. Between 685 and 225 kyrs ago, less than 3 km^3 of andesite and dacite erupted from more than 15 isolated vents; these lavas are crystal-poor and show little evidence of storage in an upper crustal chamber. Approximately 200 kyr ago, ~31 km^3 of andesite erupted to form the stratocone of Volcán Tequila. The phenocryst assemblage of these lavas suggests storage within a chamber at ~2–3 km depth. After a hiatus of ~110 kyrs, ~15 km^3 of andesite erupted along the W and SE flanks of Volcán Tequila at ~90 ka, most likely from a second, discrete magma chamber located at ~5–6 km depth. The youngest volcanic feature (~60 ka) is the small andesitic volcano Cerro Tomasillo (~2 km^3). Over the last 1 Myr, a total of 128±22 km^3 of lava erupted in the Tequila volcanic field, leading to an average eruption rate of ~0.13 km^3/kyr. This volume erupted over ~1600 km^2, leading to an average lava accumulation rate of ~8 cm/kyr. The relative proportions of lava types are ~22–43% basalt, ~0.4–1% basaltic andesite, ~29–54% andesite, ~2–3% dacite, and ~18–40% rhyolite. On the basis of eruptive sequence, proportions of lava types, phenocryst assemblages, textures, and chemical composition, the lavas do not reflect the differentiation of a single (or only a few) parental liquids in a long-lived magma chamber. The rhyolites are geochemically diverse and were likely formed by episodic partial melting of upper crustal rocks in response to emplacement of basalts. There are no examples of mingled rhyolitic and basaltic magmas. Whatever mechanism is invoked to explain the generation of andesite at the Tequila volcanic field, it must be consistent with a dominantly bimodal distribution of high-Ti basalt and rhyolite for an 800 kyr interval beginning ~1 Ma, which abruptly switched to punctuated bursts of predominantly andesitic volcanism over the last 200 kyrs.
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The eruptive history of the Tequila volcanic field, western Mexico: ages, volumes, and relative proportions of lava types
Bulletin of Volcanology, 2004Co-Authors: Catherine B. Lewis-kenedi, Rebecca A. Lange, Chris M. Hall, Hugo Delgado-granadosAbstract:The eruptive history of the Tequila volcanic field (1600 km 2 ) in the western Trans-Mexican Volcanic Belt is based on 40 Ar/ 39 Ar chronology and volume esti- mates for eruptive units younger than 1 Ma. Ages are reported for 49 volcanic units, including Volcn Tequila (an andesitic stratovolcano) and peripheral domes, flows, and scoria cones. Volumes of volcanic units 1 Ma were obtained with the aid of field mapping, ortho aerial pho- tographs, digital elevation models (DEMs), and ArcGIS software. Between 1120 and 200 kyrs ago, a bimodal distribution of rhyolite (~35 km 3 ) and high-Ti basalt (~39 km 3 ) dominated the volcanic field. Between 685 and 225 kyrs ago, less than 3 km 3 of andesite and dacite erupted from more than 15 isolated vents; these lavas are crystal-poor and show little evidence of storage in an upper crustal chamber. Approximately 200 kyr ago, ~31 km 3 of andesite erupted to form the stratocone of Volcn Tequila. The phenocryst assemblage of these la- vas suggests storage within a chamber at ~2-3 km depth. After a hiatus of ~110 kyrs, ~15 km 3 of andesite erupted along the W and SE flanks of Volcn Tequila at ~90 ka, most likely from a second, discrete magma chamber lo- cated at ~5-6 km depth. The youngest volcanic feature (~60 ka) is the small andesitic volcano Cerro Tomasillo (~2 km 3 ). Over the last 1 Myr, a total of 128€22 km 3 of
Catherine B. Lewis-kenedi - One of the best experts on this subject based on the ideXlab platform.
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The eruptive history of the Tequila volcanic field, western Mexico: ages, volumes, and relative proportions of lava types
Bulletin of Volcanology, 2005Co-Authors: Catherine B. Lewis-kenedi, Rebecca A. Lange, Chris M. Hall, Hugo Delgado-granadosAbstract:The eruptive history of the Tequila volcanic field (1600 km^2) in the western Trans-Mexican Volcanic Belt is based on ^40Ar/^39Ar chronology and volume estimates for eruptive units younger than 1 Ma. Ages are reported for 49 volcanic units, including Volcán Tequila (an andesitic stratovolcano) and peripheral domes, flows, and scoria cones. Volumes of volcanic units ≤1 Ma were obtained with the aid of field mapping, ortho aerial photographs, digital elevation models (DEMs), and ArcGIS software. Between 1120 and 200 kyrs ago, a bimodal distribution of rhyolite (~35 km^3) and high-Ti basalt (~39 km^3) dominated the volcanic field. Between 685 and 225 kyrs ago, less than 3 km^3 of andesite and dacite erupted from more than 15 isolated vents; these lavas are crystal-poor and show little evidence of storage in an upper crustal chamber. Approximately 200 kyr ago, ~31 km^3 of andesite erupted to form the stratocone of Volcán Tequila. The phenocryst assemblage of these lavas suggests storage within a chamber at ~2–3 km depth. After a hiatus of ~110 kyrs, ~15 km^3 of andesite erupted along the W and SE flanks of Volcán Tequila at ~90 ka, most likely from a second, discrete magma chamber located at ~5–6 km depth. The youngest volcanic feature (~60 ka) is the small andesitic volcano Cerro Tomasillo (~2 km^3). Over the last 1 Myr, a total of 128±22 km^3 of lava erupted in the Tequila volcanic field, leading to an average eruption rate of ~0.13 km^3/kyr. This volume erupted over ~1600 km^2, leading to an average lava accumulation rate of ~8 cm/kyr. The relative proportions of lava types are ~22–43% basalt, ~0.4–1% basaltic andesite, ~29–54% andesite, ~2–3% dacite, and ~18–40% rhyolite. On the basis of eruptive sequence, proportions of lava types, phenocryst assemblages, textures, and chemical composition, the lavas do not reflect the differentiation of a single (or only a few) parental liquids in a long-lived magma chamber. The rhyolites are geochemically diverse and were likely formed by episodic partial melting of upper crustal rocks in response to emplacement of basalts. There are no examples of mingled rhyolitic and basaltic magmas. Whatever mechanism is invoked to explain the generation of andesite at the Tequila volcanic field, it must be consistent with a dominantly bimodal distribution of high-Ti basalt and rhyolite for an 800 kyr interval beginning ~1 Ma, which abruptly switched to punctuated bursts of predominantly andesitic volcanism over the last 200 kyrs.
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The eruptive history of the Tequila volcanic field, western Mexico: ages, volumes, and relative proportions of lava types
Bulletin of Volcanology, 2004Co-Authors: Catherine B. Lewis-kenedi, Rebecca A. Lange, Chris M. Hall, Hugo Delgado-granadosAbstract:The eruptive history of the Tequila volcanic field (1600 km 2 ) in the western Trans-Mexican Volcanic Belt is based on 40 Ar/ 39 Ar chronology and volume esti- mates for eruptive units younger than 1 Ma. Ages are reported for 49 volcanic units, including Volcn Tequila (an andesitic stratovolcano) and peripheral domes, flows, and scoria cones. Volumes of volcanic units 1 Ma were obtained with the aid of field mapping, ortho aerial pho- tographs, digital elevation models (DEMs), and ArcGIS software. Between 1120 and 200 kyrs ago, a bimodal distribution of rhyolite (~35 km 3 ) and high-Ti basalt (~39 km 3 ) dominated the volcanic field. Between 685 and 225 kyrs ago, less than 3 km 3 of andesite and dacite erupted from more than 15 isolated vents; these lavas are crystal-poor and show little evidence of storage in an upper crustal chamber. Approximately 200 kyr ago, ~31 km 3 of andesite erupted to form the stratocone of Volcn Tequila. The phenocryst assemblage of these la- vas suggests storage within a chamber at ~2-3 km depth. After a hiatus of ~110 kyrs, ~15 km 3 of andesite erupted along the W and SE flanks of Volcn Tequila at ~90 ka, most likely from a second, discrete magma chamber lo- cated at ~5-6 km depth. The youngest volcanic feature (~60 ka) is the small andesitic volcano Cerro Tomasillo (~2 km 3 ). Over the last 1 Myr, a total of 128€22 km 3 of
Anne Christine Gschaedler - One of the best experts on this subject based on the ideXlab platform.
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Fermentative capacity of Saccharomyces and non-Saccharomyces in agave juice and semi-synthetic medium
LWT - Food Science and Technology, 2015Co-Authors: Luis Eduardo Segura Garcia, Patricia Taillandier, Cédric Brandam, Anne Christine GschaedlerAbstract:Various consortia of yeasts and bacteria involved in the natural fermentation process of Tequila have been identified, particularly non-Saccharomyces yeasts. This study evaluates the fermentative capacity of two non-Saccharomyces yeasts (isolated from traditional mezcal fermentation): Kluyveromyces marxianus (DU3) and Pichia kluyveri (GRO3), and assesses their production of volatile compounds. The values found are compared with those of the same attributes of a Saccharomyces cerevisiae (AR5) isolated from Tequila fermentation. The fermentations were performed in two different media, agave juice (JA) and a semi-synthetic medium (M11). The study also compared free and immobilized yeast fermentations in the JA medium in order to evaluate the potential benefits of immobilization on the yeast behaviour. This study demonstrated the potential of non-Saccharomyces yeasts, which fermented the agave juice in the same manner as S. cerevisiae but with higher ester production. Furthermore, K. marxianus produced more higher alcohols than S. cerevisiae. This could lead to Tequila with different aroma profiles. Results were different in the synthetic medium, thus showing sensitivity to the composition of the medium. No significant differences between yeast fermentations with free and immobilized cells were detected, except for ethanol yield.
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performance evaluation of pichia kluyveri kluyveromyces marxianus and saccharomyces cerevisiae in industrial Tequila fermentation
World Journal of Microbiology & Biotechnology, 2013Co-Authors: Lorena Amayadelgado, J. Arrizon, Enrique J Herreralopez, Melchor Arellanoplaza, Anne Christine GschaedlerAbstract:Traditionally, industrial Tequila production has used spontaneous fermentation or Saccharomyces cerevisiae yeast strains. Despite the potential of non-Saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. Therefore, in this work, Agave Tequilana juice was fermented at an industrial level using two non-Saccharomyces yeasts (Pichia kluyveri and Kluyveromyces marxianus) with fermentation efficiency higher than 85 %. Pichia kluyveri (GRO3) was more efficient for alcohol and ethyl lactate production than S. cerevisiae (AR5), while Kluyveromyces marxianus (GRO6) produced more isobutanol and ethyl-acetate than S. cerevisiae (AR5). The level of volatile compounds at the end of fermentation was compared with the Tequila standard regulation. All volatile compounds were within the allowed range except for methanol, which was higher for S. cerevisiae (AR5) and K. marxianus (GRO6). The variations in methanol may have been caused by the Agave Tequilana used for the tests, since this compound is not synthesized by these yeasts.
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use of inulinases to improve fermentable carbohydrate recovery during Tequila production
Food Chemistry, 2011Co-Authors: Etienne Waleckx, Anne Christine Gschaedler, Benoit Colonnaceccaldi, Juan Carlos Mateosdiaz, Nicolas Brin, Guadalupe Garciaquezada, Socorro Villanuevarodriguez, Pierre MonsanAbstract:Abstract For Tequila production, blue agave heads are cooked to hydrolyse their fructan content and release fermentable carbohydrates. However, this hydrolysis is not complete and the juice generated during cooking (cooking honey) contains fructans incompletely hydrolysed. Several distilleries perform an additional acidic hydrolysis on honey to improve fermentable carbohydrate recovery, but this treatment presents many disadvantages. As an alternative, we describe an enzymatic treatment with Fructozyme L, a preparation of inulinases. Optimal laboratory conditions for agave fructan hydrolysis using this preparation were 60 °C and a pH of 4.0–5.0. A concentration of 0.02% (V/V of honey) was needed to achieve more than 90% of fructan hydrolysis in the honey, after a 12 h treatment. These conditions were validated by two industrial trials during which enzymatic hydrolysates were successfully fermented and distilled, and volatile compound composition and sensory qualities of the Tequila were assured.
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hydrolysis of fructans from agave Tequilana weber var azul during the cooking step in a traditional Tequila elaboration process
Food Chemistry, 2008Co-Authors: Etienne Waleckx, Anne Christine Gschaedler, Benoit Colonnaceccaldi, Pierre MonsanAbstract:Abstract In traditional Tequila production, the heads of Agave Tequilana Weber var. azul are cooked in brick ovens to hydrolyze the fructan content and release fermentable sugars. The juice generated during cooking (known as “cooking honey”) was collected periodically in a Tequila distillery and characterized to study the efficiency of fructan hydrolysis. The complex structure of fructans from A. Tequilana was confirmed. The generation of 5-(hydroxymethyl)-furfural, an increase in absorbance and °Brix, and a decrease in pH and apparent average degree of polymerization of fructans during cooking were observed. The conversion of fructans in the flowing honey increased gradually from 20% at the onset of cooking to 98% after 25.5 h, where fructose represented more than 80% of the total carbohydrates. The proportion of non-hydrolyzed fructans in the cooking honey collected before this time resulted in a total ethanol loss of 6% in the Tequila distillery investigated.
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increasing fermentation efficiency at high sugar concentrations by supplementing an additional source of nitrogen during the exponential phase of the Tequila fermentation process
Canadian Journal of Microbiology, 2002Co-Authors: J. Arrizon, Anne Christine GschaedlerAbstract:In the Tequila industry, fermentation is traditionally achieved at sugar concentrations ranging from 50 to 100 g·L1. In this work, the behaviour of the Saccharomyces cerevisiae yeast (isolated from the juices of the Agave Tequilana Weber blue variety) during the agave juice fermentation is compared at different sugar concentrations to determine if it is feasible for the industry to run fermentation at higher sugar concentrations. Fermentation efficiency is shown to be higher (above 90%) at a high concentration of initial sugar (170 g·L1) when an additional source of nitrogen (a mixture of amino acids and ammonium sulphate, different than a grape must nitrogen composition) is added during the exponential growth phase.Key words: Saccharomyces cerevisiae, fermentation efficiency, nitrogen source, Tequila.
Pierre Monsan - One of the best experts on this subject based on the ideXlab platform.
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use of inulinases to improve fermentable carbohydrate recovery during Tequila production
Food Chemistry, 2011Co-Authors: Etienne Waleckx, Anne Christine Gschaedler, Benoit Colonnaceccaldi, Juan Carlos Mateosdiaz, Nicolas Brin, Guadalupe Garciaquezada, Socorro Villanuevarodriguez, Pierre MonsanAbstract:Abstract For Tequila production, blue agave heads are cooked to hydrolyse their fructan content and release fermentable carbohydrates. However, this hydrolysis is not complete and the juice generated during cooking (cooking honey) contains fructans incompletely hydrolysed. Several distilleries perform an additional acidic hydrolysis on honey to improve fermentable carbohydrate recovery, but this treatment presents many disadvantages. As an alternative, we describe an enzymatic treatment with Fructozyme L, a preparation of inulinases. Optimal laboratory conditions for agave fructan hydrolysis using this preparation were 60 °C and a pH of 4.0–5.0. A concentration of 0.02% (V/V of honey) was needed to achieve more than 90% of fructan hydrolysis in the honey, after a 12 h treatment. These conditions were validated by two industrial trials during which enzymatic hydrolysates were successfully fermented and distilled, and volatile compound composition and sensory qualities of the Tequila were assured.
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hydrolysis of fructans from agave Tequilana weber var azul during the cooking step in a traditional Tequila elaboration process
Food Chemistry, 2008Co-Authors: Etienne Waleckx, Anne Christine Gschaedler, Benoit Colonnaceccaldi, Pierre MonsanAbstract:Abstract In traditional Tequila production, the heads of Agave Tequilana Weber var. azul are cooked in brick ovens to hydrolyze the fructan content and release fermentable sugars. The juice generated during cooking (known as “cooking honey”) was collected periodically in a Tequila distillery and characterized to study the efficiency of fructan hydrolysis. The complex structure of fructans from A. Tequilana was confirmed. The generation of 5-(hydroxymethyl)-furfural, an increase in absorbance and °Brix, and a decrease in pH and apparent average degree of polymerization of fructans during cooking were observed. The conversion of fructans in the flowing honey increased gradually from 20% at the onset of cooking to 98% after 25.5 h, where fructose represented more than 80% of the total carbohydrates. The proportion of non-hydrolyzed fructans in the cooking honey collected before this time resulted in a total ethanol loss of 6% in the Tequila distillery investigated.
