Pulque Production Research Articles

A Semi-Continuous Fermentation Process for Pulque Production Using Microfiltration-Sterilized Aguamiel and Aseptic Conditions to Standardize the Overall Quality of the Beverage

Despite the current appreciation of pulque as a probiotic fermented beverage, pulque has been also regarded as a poor-quality product, particularly due to the lack of sanitary control during its elaboration. To address this problem, a semi-continuous fermentation system was established, emulating the artisanal production process. Microfiltration-sterilized aguamiel was employed as the substrate, whereas a good-quality pulque was used as the fermentation inoculum. During the fermentation, the physicochemical, microbiological (lactic acid and Leuconostoc-type bacteria and yeasts) and sensory characteristics of the must were monitored. The isolated microorganisms were identified by molecular biology and MALDI-MS techniques. The sterilization of aguamiel by microfiltration did not negatively affect its physicochemical attributes. After 6–8 days of operation of the semi-continuous bioreactor, the fermentation reached a quasi-stationary state considering most of the parameters monitored during the experiment. The final fermentation product presented similar physicochemical, microbial and sensory properties to those of the pulque inoculum. The genera identified were Leuconostoc, Lentilactobacillus, Lactobacillus, Liquorilactobacillus, Fructilactobacillus and Saccharomyces. The strains Lentilactobacillus diolivorans and Liquorilactobacillus capillatus and uvarum have not been previously isolated from pulque. In conclusion, the fermentation system developed in this work was effective to standardize the quality of pulque while preserving the positive attributes of the artisanal process, thus harnessing the probiotic properties of pulque.

Temporary immersion bioreactor as an efficient method for in vitro propagation of Agave marmorata

Agave marmorata is an important wild species in Mexico for mezcal and pulque production. Propagation by suckers and seeds is not sufficient to restore wild populations. The aim of this study was to develop a protocol for large-scale micropropagation of A. marmorata using a temporary immersion bioreactor (TIB). The effect of liquid medium using a TIB and semi-solid medium as the control treatment was compared. Different immersion frequencies and culture medium volumes per explant were evaluated in the TIB. In all treatments, the percentage of hyperhydricity, number of shoots per explant, shoot length, and total chlorophyll and carotenoid content were evaluated. In addition, the survival rate during acclimatization was evaluated. The results obtained show that the TIB with an immersion of 2 min every 8 h and with a culture medium volume of 50 mL had the best developmental parameters, with 19.60 shoots per explant, a shoot length of 1.74 cm and a percentage of hyperhydricity of 3.33 %. The highest chlorophyll content was observed in temporary immersion every 8 h, with 100, 75 and 50 mL of culture medium per explant. Regarding carotenoid content, the highest content was found at the 8 and 12 h immersion frequencies, with the culture medium volumes of 100, 75 and 50 mL per explant. For acclimatization, no differences were found in the survival rate between the culture systems evaluated. In conclusion, this study demonstrates that the use of a TIB is an alternative for large-scale micropropagation of A. marmorata.

Diversity of reproductive characters, seed set, and viability of Agave seeds used for pulque production and their wild relatives in Tlaxcala, Mexico

Agave is one of the most important genera of plants in Mexico in terms of biodiversity and cultural and economic impact; however, its reproductive traits and breeding systems are poorly known. In addition, clonal propagation of agave cultures and the interruption of sexual reproduction may lead to differences not only in reproductive traits but also in seed set and seed viability across species and between wild plants and Agave landraces. Hence this research evaluated the morphological variation of flowers, fruits, and seeds throughout the infructescence development of pulquero agave landraces (Agave americana, A. mapisaga, and A. salmiana) and their wild relatives (A. salmiana) using statistical analyses. Additionally, seed set and seed viability (tetrazolium test) were estimated for traditional (metepantle) and intensive (monoculture) cultivation systems. The analysis of flowers allowed differentiating between species (A. mapisaga and A. salmiana), while the analysis of fruits separated wild from cultivated plants. Wild agaves attained seed set values close to 0.5, and cultivated agaves, less than 0.2; the lowest seed set values (0.04) were observed under monoculture. Seed viability percentages depended on the taxon analyzed, with no clear differences between wild and cultivated taxa. There were positive correlations between branch length, fruit number, black (potentially viable) seed number, and the percentage of viable seeds. The highest percentage of viable seeds was recorded in the low and middle parts of the infructescence. Our results demonstrate that reproductive traits are suitable for recognizing morphological groups across species and between wild and landrace agaves. They also show that intensive and prolonged clonal propagation is associated with low seed set and seed viability values in Agave landraces.

Analysis of the Microbial Diversity and Population Dynamics during the Pulque Fermentation Process

Pulque is the most-studied traditional Mexican alcoholic beverage prepared by fermentation of the fresh sap (aguamiel, AM) extracted from different Agave species (maguey) cultivated for pulque production. This beverage has been produced mainly in the Central Mexico Plateau since pre-Columbian times. In this contribution, we report the analysis of the bacterial and fungal diversity through 16S rRNA gene V3–V4 fragment amplicon and ITSR1 sequencing associated with the tissue of the walls (metzal) of the cavity or cajete, where the sap accumulates in producing plants for its daily extraction, in AM, and during four fermentation stages for pulque production. The results led to determining which microorganisms detected in the plant tissue are present in AM and maintained during the fermentation process. The results showed that eight bacterial OTUs (Lactobacillus, Leuconostoc, Weisella, Lactococcus, Acetobacter, Gluconobacter, Zymomonas, and Obesumbacterium) and five fungal OTUs (Kazachstania, Kluyveromyces, Saccharomyces, Hanseniaspora, and the OTU O_Saccharomycetales) were present from metzal to AM and during all the stages of the fermentation analyzed. The detected diversity was considered the microbial core for pulque fermentation, comprising up to ~84% of the total bacterial diversity and up to ~99.6% of the fungal diversity detected in the pulque produced from three plants of A. salmiana from the locality of Huitzilac, Morelos, Mexico. This study provides relevant information on the potential microorganisms responsible for pulque fermentation, demonstrating that the core of microorganisms is preserved throughout the elaboration process and their association with the AM and fermented beverage physiochemical profile.

Differentiating Knowledge of Agave Landraces, Uses, and Management in Nanacamilpa, Tlaxcala

Pulque is a product made from the fermentation of the sap (aguamiel ) of certain agaves and its consumption has been recorded since pre-Hispanic times. The effort to recognize the landraces of the Agave genus used to produce pulque and the study of its traditional knowledge remain limited. Studies regarding this topic have centered on farmers (experts) with the biggest production capacity. This work analyzes in different ways the knowledge that experts and non-experts (general population) have regarding the usage and management of agave landraces in Nanacamilpa, Tlaxcala, one of the most iconic pulque production locations in Mexico. Two-hundred and twenty-two semi-structured interviews were carried out with non-experts and 22 with experts. The non-experts recognized 12 agave landraces, whilst experts recognized eight landraces that are mainly used to obtain aguamiel. The most important landrace that they identified was the Agave salmiana, due to the sweetness of its aguamiel and flexibility of its leaves. In total, 92 uses of agave landraces were recorded: 64 direct uses and 28 derivative uses. The oldest participants know most of its uses, but the younger participants recorded 48 uses, which indicates that agaves are a valuable resource for new generations. Experts mentioned uses directly related to the production of plants, aguamiel, and pulque, whilst non-experts included more categories of use. The agaves used for the production of pulque are of great importance for local biodiversity, culture, and economy.

Morphological and genetic diversity of traditional varieties of agave in Hidalgo State, Mexico.

The agaves are plants of cultural importance which have been used by humans for about 10,000 years and about 40 specific uses. The most culturally and economically important of those uses are for the production of fermented (pulque) and distilled beverages (mescal). Pulque continues to be produced in nearly all of Mexico, and the agaves used for this purpose have shown domestication syndrome. We carry out an ethnobotanical, morphological, and genetic analysis of the traditional varieties of pulque agave used in the production of aguamiel (agave sap) and pulque in the state of Hidalgo. We did semi-structured interviews, free listings, and tours with 11 agave managers. We analyzed morphology and studied genetic diversity and structure using nuclear microsatellites. We found wild-collected, tolerated, transplanted, and cultivated varieties of agave. This comprised 19 traditional varieties of pulque agave, 12 of them in production during the study, which corresponded to the species Agave americana, A. salmiana y A. mapisaga and five intraspecific entities. The varieties were grouped morphologically according to a management gradient; the wild-collected varieties were the smallest, with more lateral teeth and a larger terminal spine. The cultivated varieties clearly exhibited domestication syndrome, with larger plants and smaller dentition. The expected heterozygosity (He) of the varieties ranged from 0.204 to 0.721. Bayesian clustering suggested the existence of three genetic groups, both at the level of traditional varieties of pulque agaves and for management categories, a result that matches multivariate clustering. Pulque producers in the studied localities maintain high agrobiodiversity. The cultivated varieties exhibit domestication syndrome, as has been reported for other species of the genus with the same selection purposes. Our results support the hypothesis of a decrease in genetic diversity in crops compared to wild-growing agaves, which seems to be due to vegetative propagation, among other factors.

Sustainable Production of Pulque and Maguey in Mexico: Current Situation and Perspectives

Pulqueis a traditional Mexican fermented, non-distilled alcoholic beverage produced by fermenting the fresh sap (aguamiel) extracted from severalAgave(maguey) species cultivated for pulque production (mainlyA. salmiana). This beverage was produced and consumed since Pre-Hispanic times by Mesoamerican civilizations, mainly in the Mexican Central Plateau, and is one of the essential alcoholic beverages produced and consumed during several centuries in Mexico. By 2019, annual pulque production was reported in 171,482 billion liters. Nevertheless, traditional pulque production faces several significant limitations, including the disappearance of large agave plantations and the extent of time required (at least 5 years) to complete the plant maturation for aguamiel extraction; traditional production practices; and the lack of an efficient stabilization process of the fermented product resulting in low shelf life. In opposition, successful examples of sustainable cultivation of maguey species for aguamiel extraction and the fermentation process's industrialization resulted in high-quality pulque production, with international exportation certification. In this contribution, we present a review of the most relevant aspects of the history and commercial relevance of pulque, the causes that resulted in its production debacle during the first half of the twentieth century, the current situation of its traditional production, and the successful efforts of industrial production of the beverage. We describe recent results on the analysis of the physicochemical characteristics of aguamiel and on the microbiology of the beverage explored by metagenomic techniques that can be proposed as a baseline to redefine the quality criteria of the beverage and to define for the first time a microbiological core to optimize its production. We describe the relevance of maguey species for aguamiel production as a fundamental element of agroforestry and the relevance of its sustainable production, in four sustainable plantation models to maintain a stable plant population to ensure the continuous extraction of aguamiel and pulque production. Finally, we describe some successful examples of beverage industrialization and potential applications of several microorganisms isolated from aguamiel, pulque, aguamiel concentrates, and the maguey to produce high-value bioactive products.

Competitiveness and innovation in the pulquera industry, an economic analysis

Maguey is closely related to the marginalized areas of Mexico and lacks innovation processes; it mainly produces in Oaxaca for Mezcal and the production of pulque in Hidalgo and Tlaxcala. The objective of this study was to financially assess the pulque industry through its differentiation, generating a mead production project for agave syrup with respect to a project that only produces pulque considering the price volatility in states of Hidalgo, Tlaxcala, and Oaxaca. The hypothesis is that uncertainty creates opportunities that add value and benefit the producer. Method: Maguey pulquero prices and yields from 2005 to 2018 were obtained from SIAP. Production costs and investments were obtained from the Xamini S.P.R. of R. I. and were considered for the three states. The possibility of innovating pulque process from a traditional point of view through the Net Present Value (NPV) was analyzed; however, since it does not consider the price volatility, an evaluation was used using real options with binomial trees and Black-Scholes formulas with expansion scenarios to two hectares. Results: Hidalgo had, on average, the best yields, and which positions him as the main producer of this drink; however, its trend was downward. Oaxaca was the entity with the highest critical value (1.771) because it presented greater price volatility; therefore, the risk in investment is higher. Through the traditional evaluation, the projects in the pulque industry of Hidalgo and Tlaxcala were accepted with values ​​greater than unity, not so for Oaxaca. With the evaluation of real options, once it is innovated, the project increased six times more for Hidalgo and Tlaxcala increased 37 times more. The numbers turned positive for Oaxaca, but it did not recover the investment initially; a similar situation occurs when the option is given to expanding the innovation to two hectares. With the evaluation of real options, once it is innovated, the project increased six times more for Hidalgo and Tlaxcala increased 37 times more, for Oaxaca the Discussion: For a differentiated product such as agave syrup, the risk increases, but also the possibilities of increasing your income and being competitive in the market, which happens when the product is associated with the current needs of the consumer. This applies to Hidalgo and Tlaxcala, however, for Oaxaca, the project to differentiate the pulque industry is not very viable, since its production is irrelevant compared to mezcal. This study confirmed the hypothesis, when the product is differentiated in its production process, benefits increase, despite the uncertainty.

Substance and Seduction: Ingested Commodities in Early Modern Mesoamerica

This edited volume breaks new ground in critical food studies by exploring the allure that Africans, Indians, and Europeans held for ingested commodities such as alcohol, chocolate, peyote, sugar, and tobacco in Mesoamerica. The ability of these commodities to seduce peoples across racial and socioeconomic lines grants them a level of agency in their own right. Using consumption as an analytical tool helps the volume’s contributors illuminate the social meaning embedded within sensorial experiences. The book’s six chapters are grouped thematically into two sections, with the first foregrounding seduction and the second emphasizing substance.In the first section, Martin Nesvig considers how the meaning ascribed to hallucinogens such as peyote, teonanacatl, and ololiuqui changed over time, eventually leading to “a process of creolization” in the way that they were consumed in mainstream society (28). Although ritual specialists originally used hallucinogens to divine, heal, and interpret the cosmos, their consumption expanded to mixed-race peoples in the sixteenth and seventeenth centuries, creating a hybrid Mexican custom. Stacey Schwartzkopf examines the production and ingestion of mead, wine, chicha, and aguardiente de caña among Maya peoples in colonial Guatemala. Schwartzkopf notes that the Maya resisted attempts to centralize alcohol production and that many Maya preferred sugar-based drinks over Spanish wine (60). Despite the fact that much of colonial society drank, colonial elites’ anxieties surrounding racial mixing prompted them to vigorously control the licensing of alcohol (67). Kathryn E. Sampeck and Jonathan Thayn investigate cacao usage in Central America and Mexico, tracking recipes to see how tastes traveled across the Atlantic and evaluating the palates of Mesoamericans and French, British, and Anglo-American colonists. Using GIS modeling, Sampeck and Thayn show that Maya and southern Nahua peoples shared similar preferences for cacao recipes and that most of Europe used British recipes as a base for their chocolate cuisine (89).In the second section, Joel W. Palka surveys tobacco cultivation and trade among the indomitable Lacandon Maya peoples in the late nineteenth century. Palka traces the social and economic changes that occurred due to the continued demand for the crop, including polygamy, a practice that increased the number of hands available to help with production. Moreover, Palka highlights the transformations in Lacandon religion as increased contact with outsiders elevated Akyantho, the god of trade and foreigners, over other deities (121). Joan Bristol discerns how elites projected their anxieties about racial purity onto the production and consumption of pulque in colonial Mexico. Bristol draws parallels between a drink known as coyote—made of pulque, dark honey, and palo de timbre—and the ethnonym coyote, used to describe a person that was “three-quarters indigenous and one-quarter Spanish” (135). According to colonial officials, the mixed nature of coyote drinks and people made them both inferior. Guido Pezzarossi employs Michel Foucault’s biopolitics to show how authoritarian governments stripped Indians of their political standing as vassals in colonial Guatemala (150). Pezzarossi uses his findings from archeological and historical research to show how alcohol, cacao, and sugar regulation in Guatemala intersected with the colonial government’s purported concerns for the health of native populations. This book’s fine forward by Marcy Norton and afterword by Carla D. Martin maintain that historians can deepen their understanding of subaltern agency by examining the purposeful attainment of heightened sensory states through seductive commodities since their consumption frequently provoked responses from powerful officials. In short, the many insights that the contributors provide in this bold volume should stimulate debate and produce new avenues of research for scholars of Mesoamerican and Latin American history and food studies.

Evolution of Fructans in Aguamiel (Agave Sap) During the Plant Production Lifetime.

Aguamiel is the sap collected from agave, while pulque is the result of the natural fermentation of aguamiel. Despite its ancestral origin and numerous publications on pulque production, little is known about the evolution and concentration of sugars and fructo-oligosaccharides in aguamiel, either during its daily accumulation or through the agave production lifetime. In this study, we examined aguamiel composition in three agave plants during their productive lifetime (4 to 9 months). After each collection, the agave pine is scraped to induce aguamiel to flow into an internally created cavity (cajete), producing a residual bagasse (metzal). We found that the concentration of agave fructans and sucrose, as well as the fructan profile, change during the aguamiel production process. During the daily collection, a small amount of agave fructans released from the pine by scraping is drawn into the cajete with the first milliliters of sap where it is then diluted with the inflow of aguamiel. The main component of aguamiel is the sucrose produced in high concentration in the leaves through photosynthesis and then hydrolyzed in the cajete as aguamiel accumulates. We also describe how the fructan profile changes during the accumulation of aguamiel in the cajete. In addition to the varying amount of sucrose that is hydrolyzed in the aguamiel accumulated, we found that fructo-oligosaccharides are either diluted, consumed, or hydrolyzed, depending on the plant and its production stage, thus yielding different fructan profiles. New fructo-oligosaccharides are, in some cases, synthesized by bacteria present in aguamiel. These profiles were also observed in aguamiel collected from ten different plants in the same production region. We also found that a considerable amount of agave fructans is lost in metzal (bagasse), the agave material that is scraped and thrown away twice a day during the production process.

Deep microbial community profiling along the fermentation process of pulque, a biocultural resource of Mexico

The biggest non-tree perennial plant species endemic to Mexico were called metl in the Nahua culture; during colonial times, renamed with the Antillean word maguey. Carl von Linné finally renamed them as Agave, a Greek-Latin root word meaning admirable. Since pre-Columbian times, one of the major products obtained from some Agave species is the fermented beverage called pulque or octli. This beverage represents an ancient biotechnological development obtained by the natural fermentation of mead from such plants. Pulque played a central role in Mexican pre-Columbian cultures, while in recent times, there has been a renewed interest in it, due to its high content in nutrients and probiotics. In this study, we used massive sequencing of the 16S rRNA gene and the ribosomal internal transcribed spacer (ITS) to profile the pulque microbiome. We identified 2,855 bacteria operational taxonomic units (OTUs) and 1,494 fungi species in the pulque fermentation. Our results provide the most diverse catalog of microbes during pulque production reported so far. These findings allowed us to identify previously unidentified and core microbes resilient during pulque production, with the potential to be used as fermentation stage biomarkers. We confirmed previous reports of pulque microbes and discovered new ones like the bacteria Sphingomonas and Weisella. Among fungi we found that Saccharomyces cerevisiae was second to Candida zemplina in the studied pulque samples.

Morphological Diversity and Genetic Relationships in Pulque Production Agaves in Tlaxcala, Mexico, by Means of Unsupervised Learning and Gene Sequencing Analysis.

Pulque is one of the oldest fermented beverages, with its origins dating back to pre-Hispanic Mexico. Recently, public consumption has increased. However, the majority of Agave plantations for pulque production have disappeared or been abandoned in recent decades. To create strategies for the conservation and production of pulque agaves, it is necessary to first determine their taxonomic identities and to better understand their genetic and morphological diversity. Despite the historical importance of pulque in Mexico, little attention has been placed on the study of Agave plants used for its production. Therefore, we analyzed the morphological diversity of vegetative characters of nine landraces of two Agave species (A. salmiana and A. mapisaga) which are widely cultivated for pulque production in Tlaxcala, Mexico. The analysis of morphological characters showed that the landraces largely clustered based on classic taxonomic relationships. One cluster of landraces associated with Agave mapisaga var. mapisaga and another with A. salmiana subsp. salmiana, but with the exception of A. salmiana subsp. salmiana “Ayoteco”, which is more closely related with A. mapisaga var. mapisaga. Additionally, we analyzed the genetic relationships between 14 landraces and wild individuals using molecular markers (trnL and ITS). The identified genetic variants or haplotypes and genetic pools mainly corresponded with the species. In the case of “Ayoteco”, incongruence between markers was observed. Low selection intensity, genetic flow events, and the plasticity of morphological traits may explain the high number of landraces without clear differences in their morphological diversity (vegetative characters) or genetic pools. The use of reproductive traits and massive sequencing might be useful for identifying possible morphological and genetic changes in the Agave landraces used for pulque production.

RESPUESTA MORFOGENÉTICA DE DOS ESPECIES DE AGAVE REGENERADAS IN VITRO

<p><strong>Background</strong>: Agaves in Mexico are plants with great economic, gastronomic and cultural value. Despite the multiple forms of reproduction of plants belonging to the genus <em>Agave</em>, several of these species are threatened due to their slow growth, low percentage of seed viability, destruction of its habitat, excessive looting, interruption of its ripening cycle due to the use of their different organs,however, it has been posible to establish biotechnological techniques for its propagation, conservation and genetic improvement. <strong>Objective</strong>: At the present work were selected a representative species of Agave, one of them for pulque production (<em>A. salmiana</em>) (As) and the other one in the production of mezcal (<em>Agave marmorata</em>) (Am) with the aim to establish an efficient micropropagation protocol optimizing the concentrations of the citokinin benzylaminopurine (BA) and the auxin 2,4-Dichlorophenoxyacetic acid (2,4-D), on the <em>in vitro </em>morphogenesis of both species.<strong> Methodology: </strong>Two <em>in vitro </em>culture systems were conducted in three explants (zygotic embryonic axis (E1), <em>in vitro </em>meristematic zone (E2) and <em>ex vitro</em> meristematic zone (E3)). <strong>Results</strong>: Shoots regeneration was achieved in all tested experiments; the highest number of shoots in As was 23.8 for explant using the E2 of directly regenerated <em>in vitro</em> germinated plants using a concentration of 10 mg L<sup>-1</sup> of BA, while in Am 24.7 shoots/explant were obtained with 5 mg L<sup>-1</sup> of BA using the zygotic embryonic axis who throughing a callus phase. <strong>Implications</strong>: The results obtained help to understand the importance of developing specific micropropagation protocols for each species, as well as contribuiting in the masive multiplications of <em>A. salmiana</em> and <em>A. marmorata</em> by understanding the effect of cytokinin BA and auxin 2,4-D and their combination in the formation of shoots by direct and indirect organogenesis. This provides a conservation alternative and an opportunity to startgenetic improvment programs. <strong>Conclusion</strong>: The results of this research suggest that the choice of explant, multiplication system, species and plant growth regulators are the key to obtain a greater number of shoots with high <em>ex vitro</em> survival rates.</p>

Management, morphological and genetic diversity of domesticated agaves in Michoac\xe1n, M\xe9xico

BackgroundPulque is a fermented beverage prepared with sap of Agave species in Mexico. Management of agaves for this purpose has motivated domestication of some species and high phenotypic variation that commonly causes uncertainty about the taxonomic identity of varieties traditionally managed by people. This study assumed that varieties of crop species continually arise from mutations, sexual reproduction and hybridization, among other processes, and some of them are favoured and maintained by humans. Identifying these varieties may be difficult and a challenging issue for botanists and evolutionary biologists studying processes of domestication. Through a case study, we analysed the traditional varieties of agaves used to produce pulque in Michoacán, Mexico. We aimed at identifying the varieties, analysing the relatedness among them and developing a methodological approach that could help solve taxonomic problems and study variation under domestication of this and other plant groups. We documented (1) the traditional varieties of agave used and their identity, (2) how these varieties are perceived, used and managed by the local people and (3) how management influences phenotypic and genetic variation among varieties.MethodsWe interviewed pulque producers in two localities of the state of Michoacán, Mexico, where we recorded management practices of agaves, the traditional varieties used, the attributes characterizing those varieties, the varieties preferred by people, and features and mechanisms of selection. We conducted multivariate analyses of morphological features of the agave varieties, as well as genetic diversity and genetic distance studies among agave varieties through 11 nuclear microsatellites.ResultsSeven traditional varieties of Agave were recorded in the study area. Multivariate analyses of morphology identified varieties belonging to the species A. salmiana, A. mapisaga and, presumably, A. americana. The preferred varieties have morphological features selected to make easier their management and produce higher sap yields. Genetic diversities (HE = 0. 470 to 0.594) were high compared with other Agave species with similar life history traits and use. Genetic distance analyses grouped the varieties “Verde” and “Negro” (identified as A. salmiana), whereas the varieties “Tarímbaro” and “Listoncillo” (identified as A. mapisaga) formed another group. The varieties “Blanco” and “Carrizaleño” (most probably being A. americana) clustered with varieties of A. salmiana, whereas the variety “Cenizo” appeared as a distinct group. Bayesian analysis indicated that most individuals of varieties of A. salmiana form a group and those of the varieties of A. mapisaga form another, whereas individuals of the varieties putatively belonging to A. americana clustered in similar proportions with both groups.ConclusionsThe traditional pulque production in the study area is an ongoing practice. It is still an important source of products for direct consumption by households and generation of economic incomes and as part of the cultural identity of local people. The most used traditional variety exhibited a marked gigantism, and although these agaves are mainly asexually propagated, populations have high genetic diversity. The local producers promote the maintenance of different traditional varieties. Our study shows the value of an integral research approach including ethnobiological, morphological and genetic information to clarify the state of variation influenced by humans on agaves, but it would be helpful to study other organisms under domestication. In addition, such approach would help to document human and non-human mechanisms generating crop varieties managed by local people.

Influence of fermentation by different microflora consortia on pulque and pulque bread properties.

Pulque bread is a traditional Mexican product obtained by fermentation using microflora present only in pulque. In this study, the possibility of creating a pulque microbial consortium under laboratory conditions and its applications were evaluated. A laboratory-made consortium was compared with a consortium originating in Mexico in bread and pulque production. They were tested in various growth medium systems: pulque made from agave sap and malt extract, Mexican wheat and rye pulque bread, and European wheat and rye bread. Depending on the growth medium, consortiums showed differing influence on many factors, such as specific volume, weight loss after baking, soluble proteins, and crust and crumb color. Indigenous starters increased sensorial acceptance of pulque and Mexican rye bread, decreased pH, and increased titratable acidity of the breads at the highest level whereas laboratory consortia improved sensory acceptance of wheat breads. The laboratory-prepared starter in some cases improved antiradical activity. All pulques received similar consumer evaluations. However, malt pulque was the least appreciated beverage. The results show the possibility of creating a pulque microbial consortium under laboratory conditions. Depending on the flour type and the breadmaking technique, the use of a particular microbial consortium allowed modification of certain physicochemical parameters. In conclusion, it is feasible to modify bread parameters to obtain features corresponding to consumer demands by using an appropriate microflora, pulque, or flour type. Moreover, this research describes, for the first time, the use of rye malt for pulque and rye flour for pulque bread preparation as raw materials. © 2019 Society of Chemical Industry.

El patrimonio gastronómico del municipio de Toluca: el caso del pulque y las pulquerías (1841-1920)

In this article we outline some historical elements of pulque and pulquerias in the municipality of Toluca in the period 18411920, particularly the production, marketing and consumption of the drink, are identified. The method used was microhistory with information obtained from the Historical Archive of the Municipality of Toluca and biblio-newspaper sources. The results show that there was a significant production of pulque in the municipality, there was a large number of establishments laid it out, the women were important in the marketing of the drink, and the railroad contributed to the distribution of the drink. We conclude that this gastronomic heritage was important for the municipality and the consumption of the beverage was widespread among the population.

Pulque, a Traditional Mexican Alcoholic Fermented Beverage: Historical, Microbiological, and Technical Aspects.

Pulque is a traditional Mexican alcoholic beverage produced from the fermentation of the fresh sap known as aguamiel (mead) extracted from several species of Agave (maguey) plants that grow in the Central Mexico plateau. Currently, pulque is produced, sold and consumed in popular districts of Mexico City and rural areas. The fermented product is a milky white, viscous, and slightly acidic liquid beverage with an alcohol content between 4 and 7° GL and history of consumption that dates back to pre-Hispanic times. In this contribution, we review the traditional pulque production process, including the microbiota involved in the biochemical changes that take place during aguamiel fermentation. We discuss the historical relevance and the benefits of pulque consumption, its chemical and nutritional properties, including the health benefits associated with diverse lactic acid bacteria with probiotic potential isolated from the beverage. Finally, we describe the actual status of pulque production as well as the social, scientific and technological challenges faced to preserve and improve the production of this ancestral beverage and Mexican cultural heritage.

Influence of thermal effect on sugars composition of Mexican Agave syrup

Agave syrup is a fermentable by-product from the Agave industry that is used for pulque production, a typical Mexican fermented beverage. However, to date, the information available on its physicochemical composition is scarce, with this study being one of the first contributions on the subject. Here the influence of thermal treatment at 121ºC/15 min on the physicochemical composition of agave syrup was studied. The chemical composition based on sugar content was evaluated by thin-layer chromatography and high-performance liquid chromatography. In addition, the mass spectrum is also presented. Results showed that thermal treatment promoted a change in the chemical composition of the agave syrup, particularly in sugar concentration favoring a high sucrose concentration after the sterilization process. Fructose, glucose in particular, and kestose (GF2) were detected in both samples. The presence of prebiotics such as GF2 suggests that agave syrup may be used in food and nutraceutical industries as a functional beverage.

Pulque production from fermented agave sap as a dietary supplement in Prehispanic Mesoamerica.

Although in modern societies fermented beverages are associated with socializing, celebration, and ritual, in ancient times they were also importa`nt sources of essential nutrients and potable water. In Mesoamerica, pulque, an alcoholic beverage produced from the fermented sap of several species of maguey plants (Agavaceae; Fig. 1) is hypothesized to have been used as a dietary supplement and risk-buffering food in ancient Teotihuacan (150 B.C. to A.D. 650). Although direct archaeological evidence of pulque production is lacking, organic residue analysis of pottery vessels offers a new avenue of investigation. However, the chemical components of alcoholic beverages are water-soluble, greatly limiting their survival over archaeological timescales compared with hydrophobic lipids widely preserved in food residues. Hence, we apply a novel lipid biomarker approach that considers detection of bacteriohopanoids derived from the ethanol-producing bacterium Zymomonas mobilis for identifying pulque production/consumption in pottery vessels. Gas chromatography-mass spectrometry selected ion monitoring (m/z 191) of lipid extracts of >300 potsherds revealed characteristic bacteriohopanoid distributions in a subset of 14 potsherds. This hopanoid biomarker approach offers a new means of identifying commonly occurring bacterially fermented alcoholic beverages worldwide, including palm wine, beer, cider, perry, and other plant sap- or fruit-derived beverages [Swings J, De Ley J (1977) Bacteriol Rev 41(1):1-46].

The Artisanal Production of Pulque, a Traditional Beverage of the Mexican Highlands.

Pulque is a traditional fermented alcoholic, acidic, viscous drink of the Mexican central highlands. Its production from the "aguamiel" (sap) of agave plants dates back ~1,500years and continues to be made by artisanal methods. However, the variability of pulque's quality and its instability hamper its widespread distribution and consumption. Microbiological surveys of pulque from three ranches revealed tremendous variability in the types and quantity of the indigenous microbiota. The population of lactic acid bacteria ranged from 6×10(7) to 2×10(11)CFU/mL. This variability might be attributed to the conditions on the ranches where the pulque was made. In an attempt to identify these sources of variability, the microbial populations of aguamiel and pulque from a single agave plant were determined. Surprisingly, the population size of the "unfermented" aguamiel and the pulque converged by the end of 3weeks. The potential use of bacteriocinogenic LAB and known starter cultures to improve pulque properties are discussed.