Wheat craft beer made from AFB1-contaminated wheat malt contains detectable mycotoxins, retains quality attributes, but differs in some fermentation metabolites.

Levels of aflatoxin B1 (AFB1) were measured during the production of wheat craft beer made with wheat malt contaminated with AFB1 (1.23 µg/kg). A wheat craft beer made with non-contaminated wheat malt was produced for comparison purposes. AFB1 was measured after mashing (malt after the mashing process), and in spent grain (spent grains are filtered to collect the wort - remaining sugar-rich liquid), sweet wort, green beer, spent yeast, and in beer. Physicochemical parameters (pH, titratable acidity, color parameters, total soluble solids), sugars, organic acids, alcohols, and phenolics were evaluated after mashing, and in sweet wort, green beer, and beer samples. Density and yeast counts were determined over 120 h of sweet wort fermentation every 24 h. The AFB1 levels in the final beer were 0.22 µg/L, while the spent grains and spent yeasts contained 0.71 ± 0.17 and 0.11 ± 0.03 µg/kg of AFB1, respectively. AFB1 contamination did not influence the final product's physicochemical parameters, density during fermentation, fructose, or glycerol content. Higher yeast counts were observed during the first 48 h of non-contaminated wheat craft beer fermentation, with higher ethanol, citric acid, and propionic acid contents and lower glucose, malic acid, and lactic acid contents compared with beer contaminated with AFB1. Non-contaminated wheat craft beer also had higher concentrations of gallic acid, chlorogenic acid, catechin, procyanidin A2, and procyanidin B1. AFB1 contamination of wheat malt may not affect basic quality parameters in wheat craft beer but can influence the final product's organic acid and phenolic contents. Our findings show that if wheat craft beer is made with contaminated malt, AFB1 can remain in the final product and may pose a risk to consumers.

The Impact of Yeast Encapsulation in Wort Fermentation and Beer Flavor Profile.

The food and beverage industry is constantly evolving, and consumers are increasingly searching for premium products that not only offer health benefits but a pleasant taste. A viable strategy to accomplish this is through the altering of sensory profiles through encapsulation of compounds with unique flavors. We used this approach here to examine how brewing in the presence of yeast cells encapsulated in alginate affected the sensory profile of beer wort. Initial tests were conducted for various combinations of sodium alginate and calcium chloride concentrations. Mechanical properties (i.e., breaking force and elasticity) and stability of the encapsulates were then considered to select the most reliable encapsulating formulation to conduct the corresponding alcoholic fermentations. Yeast cells were then encapsulated using 3% (w/v) alginate and 0.1 M calcium chloride as a reticulating agent. Fourteen-day fermentations with this encapsulating formulation involved a Pilsen malt-based wort and four S. cerevisiae strains, three commercially available and one locally isolated. The obtained beer was aged in an amber glass container for two weeks at 4 °C. The color, turbidity, taste, and flavor profile were measured and compared to similar commercially available products. Cell growth was monitored concurrently with fermentation, and the concentrations of ethanol, sugars, and organic acids in the samples were determined via high-performance liquid chromatography (HPLC). It was observed that encapsulation caused significant differences in the sensory profile between strains, as evidenced by marked changes in the astringency, geraniol, and capric acid aroma production. Three repeated batch experiments under the same conditions revealed that cell viability and mechanical properties decreased substantially, which might limit the reusability of encapsulates. In terms of ethanol production and substrate consumption, it was also observed that encapsulation improved the performance of the locally isolated strain.

Mandacaru fruit pulp (Cereus jamacaru D.C.) as an adjunct and its influence on Beer properties.

Beer is a complex product due to its raw materials (malt, hops, yeast, and water). Beer production can also use other matters as adjuncts. This study investigated the influence of Mandacaru fruit pulp (MFP) as an adjunct on volatile and phenolic compounds, and antioxidant properties of Beer. Worts were produced using four treatments including a control. Fermentations were conducted for 10 days at 18 °C using yeast Lachancea spp, maturated at 3 °C for 15 days, and bottled at 20 °C for 15 days. All compounds were evaluated by HPLC, and GC-MS. Worts' supplementation influenced the volatile and phenolic profile and increased the antioxidant activity of wort and Beer. Beers A (100 g of MFP/L), B (200 g of MFP/L), and C (300 g of MFP/L) presented higher ethanol and glycerol content. Beer C contained the highest antioxidant activity and total phenolic content. Worts' supplemented with MFP increased aroma formation.

Fate of enniatins in the Ale beer production stages analyzed by a validated method based on matrix-matched calibration and LC-QToF-MS.

Enniatins (ENA, ENA1, ENB and ENB1) are emerging mycotoxins reported in malt used for brewing. This study aimed to assess the fate of ENA, ENA1, ENB and ENB1 throughout Ale beer brewing using a validated method based on matrix-matched calibration (MMC) and liquid chromatography with quadrupole time-of-flight mass spectrometry detection. MMC avoided the inaccurate quantification of all enniatins, since the matrix effects that cause signal suppression have been overcome. The validated method displayed linearity (R2 > 0.99), recovery (>88%), repeatability and intermediate precision (RSD < 9.0%) in accordance with the different guidelines of method validation. The values of LOD (<0.1 µg kg-1) and LOQ (<0.5 µg kg-1) were sensitive enough to detect enniatins throughout brewing. In the Ale beer production stages, enniatins levels were significantly reduced, ensuring that beers were free of these mycotoxins. In contrast, enniatins were found in all by-products of beer production due to their low water solubility.

Proteolytic activities and profiles as useful traits to select barley cultivars for beer production.

Barley malting depends on hydrolytic enzymes that degrade storage macromolecules. Identifying barley cultivars with proteolytic activity that guarantees appropriate foaming, flavor, and aroma in the beer is of great importance. In this work, the proteolytic activity and profiles of brewing malt from Mexican barley cultivars were analyzed. Data showed that Cys- (at 50°C) and Ser-proteases (at 70°C) are the major contributors to proteolytic activity during mashing. Essential amino acids, necessary for fermentation and production of good flavor and aroma in beer, were detected at the end of mashing. According to our results, Mexican cultivar HV2005-19 exhibits similar proteolytic activities as those from cultivar Metcalfe, which is one of the most utilized for the brewing industry. Moreover, we propose Cys- and Ser-proteases as biochemical markers during mashing at 50 and 70°C, respectively, to select barley cultivars for beer production. PRACTICAL APPLICATIONS: Proteolytic activity, which depends on activation and de novo synthesis of proteases in the aleurone layer of barley seeds, is crucial in beer production. Identifying new barley varieties that have optimal proteolytic activities is of great interest for genetic improvement programs. In this study, we propose the variety HV2005-19 as a genotype with Cys- and Ser-proteases activity similar to that from Metcalfe, which is a top variety in the brewing industry.

The Effect of Brewing Process Parameters on Antioxidant Activity and Caffeine Content in Infusions of Roasted and Unroasted Arabica Coffee Beans Originated from Different Countries.

Coffee is one of the most often consumed beverages almost all over the world. The multiplicity of beans, as well as the methods and parameters used to brew, encourages the optimization of the brewing process. The study aimed to analyze the effect of roasting beans, the brewing technique, and its parameters (time and water temperature) on antioxidant activity (determined using several in vitro methods), total polyphenols, flavonoids, and caffeine content. The infusions of unroasted and roasted Arabica beans from Brazil, Colombia, India, Peru, and Rwanda were analyzed. In general, infusions prepared from roasted beans had higher antioxidant activity and the content of above-mentioned compounds. The hot brew method was used to obtain infusions with a higher antioxidant activity, while the cold brew with higher caffeine content. The phenolic compound content in infusions prepared using both techniques depended on the roasting process. Moreover, the bean's origin, roasting process, and brewing technique had a significant effect on the tested properties, in contrary to brewing time and water temperature (below and above 90 °C), which had less impact. The results confirm the importance of coffee brewing optimization.

Enhanced hydrolytic efficiency of an engineered CBM11-glucanase enzyme chimera against barley ß-d-glucan extracts.

The ß-d-glucans are abundant cell wall polysaccharides in many cereals and contain both (1,3)- and (1,4)-bonds. The ß-1,3-1,4-glucanases (EC 3.2.1.73) hydrolyze ß-(1,4)-d-glucosidic linkages in glucans, and have applications in both animal and human food industries. A chimera between the family 11 carbohydrate-binding module from Ruminoclostridium (Clostridium)thermocellumcelH (RtCBM11), with the ß-1,3-1,4-glucanase from Bacillus subtilis (BglS) was constructed by end-to-end fusion (RtCBM11-BglS) to evaluate the effects on the catalytic function and its application in barley ß-glucan degradation for the brewing industry. The parental and chimeric BglS presented the same optimum pH (6.0) and temperature (50 °C) for maximum activity. The RtCBM11-BglS showed increased thermal stability and 30% higher hydrolytic efficiency against purified barley ß-glucan, and the rate of hydrolysis of ß-1,3-1,4-glucan in crude barley extracts was significantly increased. The enhanced catalytic performance of the RtCBM11-BglS may be useful for the treatment of crude barley extracts in the brewing industry.

Simple and Sustainable Preparation of Nonactivated Porous Carbon from Brewing Waste for High-Performance Lithium-Sulfur Batteries.

The development of renewable energy sources requires the parallel development of sustainable energy storage systems because of its noncontinuous production. Even the most-used battery on the planet, the lithium-ion battery, is reaching its technological limit. In light of this, lithium-sulfur batteries have emerged as one of the most promising technologies to address this problem. The use of biomass to produce cathodes for these batteries addresses not only the aforementioned problem, but it also reduces the carbon footprint and gives added value to something normally considered waste. Here, the production, by simple and nonactivating pyrolysis, of a carbon material using the abundant "after-boiling waste" derived from beer brewing is reported. After adding a high sulfur loading (70 %) to this biowaste-derived carbon by the "melt diffusion" method, the sulfur-carbon composite is used as an effective cathode in Li-S batteries. The cathode shows excellent performance, reaching high capacity values with long-term cyclability at high current-847 mAh g-1 at 1 C, 586 mAh g-1 at 2 C, and even 498 mAh g-1 at 5 C after 400 cycles-drastically reducing capacity loss to values approaching 0.01 % per cycle. This work demonstrates the possibility of obtaining low-cost, highly sustainable cathodic materials for the design of advanced energy storage systems.

Molecular action mechanism of anti-inflammatory hydrolysates obtained from brewers' spent grain.

BACKGROUND: Brewers' spent grain (BSG) is a relevant, protein-rich by-product of the brewing process. Protein hydrolysates from different sources exert immune-regulatory actions activating toll-like receptors (TLRs), nuclear factor kappa B (NFκB), and mitogen-activated protein kinases (MAPKs). Effects of gastrointestinal digestion have been poorly studied. Here, we studied the immune-regulatory effect of BSG hydrolysates, and their in-vitro-digested products, on rat splenocytes, macrophages, and T lymphocytes RESULTS: In primary cultures of rat spleen cells, BSG hydrolysates induced interleukin 10 and tumor necrosis factor production in basal conditions. Under stimulation with lipopolysaccharide or concanavalin A, hydrolysates further induced interleukin 10 production. Tumor necrosis factor and interferon-γ were inhibited in lipopolysaccharide- and concanavalin-A-stimulated cells respectively. In vitro gastrointestinal digestion attenuated the observed effects. Splenic macrophages and T lymphocytes behaved in a similar fashion. In spleen cells from TLR2-/- and TLR4-/- mice, immune-regulatory effects were greatly reduced or abrogated. The study of signal transduction pathways indicated a major involvement of NFκB, and the contribution of MAPKs p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinases 1 and 2. CONCLUSION: BSG hydrolysates, like those obtained from other food sources, regulate the immune response, involving TLR2 and TLR4 and the activation of NFκB and MAPKs, an effect partly maintained after in vitro gastrointestinal digestion. Our data support the hypothesis of a shared, rather unspecific, mechanism of action of protein hydrolysates. © 2020 Society of Chemical Industry.

Does Inter-Organellar Proteostasis Impact Yeast Quality and Performance During Beer Fermentation?

During beer production, yeast generate ethanol that is exported to the extracellular environment where it accumulates. Depending on the initial carbohydrate concentration in the wort, the amount of yeast biomass inoculated, the fermentation temperature, and the yeast attenuation capacity, a high concentration of ethanol can be achieved in beer. The increase in ethanol concentration as a consequence of the fermentation of high gravity (HG) or very high gravity (VHG) worts promotes deleterious pleiotropic effects on the yeast cells. Moderate concentrations of ethanol (5% v/v) change the enzymatic kinetics of proteins and affect biological processes, such as the cell cycle and metabolism, impacting the reuse of yeast for subsequent fermentation. However, high concentrations of ethanol (> 5% v/v) dramatically alter protein structure, leading to unfolded proteins as well as amorphous protein aggregates. It is noteworthy that the effects of elevated ethanol concentrations generated during beer fermentation resemble those of heat shock stress, with similar responses observed in both situations, such as the activation of proteostasis and protein quality control mechanisms in different cell compartments, including endoplasmic reticulum (ER), mitochondria, and cytosol. Despite the extensive published molecular and biochemical data regarding the roles of proteostasis in different organelles of yeast cells, little is known about how this mechanism impacts beer fermentation and how different proteostasis mechanisms found in ER, mitochondria, and cytosol communicate with each other during ethanol/fermentative stress. Supporting this integrative view, transcriptome data analysis was applied using publicly available information for a lager yeast strain grown under beer production conditions. The transcriptome data indicated upregulation of genes that encode chaperones, co-chaperones, unfolded protein response elements in ER and mitochondria, ubiquitin ligases, proteasome components, N-glycosylation quality control pathway proteins, and components of processing bodies (p-bodies) and stress granules (SGs) during lager beer fermentation. Thus, the main purpose of this hypothesis and theory manuscript is to provide a concise picture of how inter-organellar proteostasis mechanisms are connected with one another and with biological processes that may modulate the viability and/or vitality of yeast populations during HG/VHG beer fermentation and serial repitching.

Carbonyl compounds and furan derivatives with toxic potential evaluated in the brewing stages of craft beer.

Carbonyl compounds and furan derivatives may form adducts with DNA and cause oxidative stress to human cells, which establishes the carcinogenic potential of these compounds. The occurrence of these compounds may vary according to the processing characteristics of the beer. The objective of this study was, for the first time, to investigate the free forms of target carbonyl compounds [acetaldehyde, acrolein, ethyl carbamate (EC) and formaldehyde] and furan derivatives [furfural and furfuryl alcohol (FA)] during the brewing stages of ale and lager craft beers. Samples were evaluated using headspace-solid phase microextraction and gas chromatography with mass spectrometric detection in selected ion monitoring mode (HS-SPME-GC/MS-SIM). Acetaldehyde, acrolein, formaldehyde and furfuryl alcohol were found in all brewing stages of both beer types, while EC and furfural concentrations were below the LOD and LOQ of the method (0.1 and 0.01 µg L-1, respectively). Boiling and fermentation of ale brewing seem to be important steps for the formation of acrolein and acetaldehyde, respectively, while boiling resulted in an increase of FA in both types of beer. Conversely, pasteurisation and maturation reduced the levels of these compounds in both types of beer. An increase in concentration of acrolein has not been verified in lager brew probably due to the difference in boiling time between these two types of beer (60 and 90 min for ale and lager, respectively).

Industrial barley residue for the production of agglomerated panels / Resíduo de cevada industrial para a produção de painéis aglomerados

This work aimed to evaluate the physical and mechanical properties based panels made of barley industrial waste and particles Pinus spp. The company Bonet Woods and Papers Ltda. in the municipality of Santa Cecilia - Santa Catarina, provided the particles Pinus spp. The barley residue was provided by AMBEV in Lages, SC. For the production of panels used were five treatments, being composed of different barley residue content and particle Pinus spp.: 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4) and 0:100 (T5), to the residue and timber respectively. Three panels were produced per treatment, totaling 15 panels. The nominal density of 650 Kg.m-3, 12% of urea formaldehyde resin, 1% paraffin, eight minutes press cycle were used in the production of panels, with a temperature of 160 °C and a maximum pressure of 40 Kgf.cm-2. For the physical properties, moisture content, density, compression ratio, thickness swelling and water absorption (2h and 24h) were determined. The mechanical properties determined were static bending, internal connection, top and surface screw pulling. With the results found it can be concluded that increasing the percentage of barley residue decreases the resistance of the panels to the physical and mechanical properties.

Neste trabalho objetivou-se avaliar as propriedades físicas e mecânicas de painéis aglomerados constituídos por resíduos de cevada industrial e partículas de Pinus spp. As partículas de Pinus spp. foram fornecidas pela empresa Bonet Madeiras e Papéis Ltda. localizada em Santa Cecília, Santa Catarina. O resíduo de cevada foi fornecido pela AMBEV, Lages, SC. Para a produção dos painéis foram utilizados cinco tratamentos, sendo compostos por diferentes teores de resíduo de cevada e de partículas de Pinus spp., respectivamente: 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4) e 0:100 (T5). Foram produzidos três painéis por tratamento, totalizando 15 painéis. Na produção dos painéis, utilizou-se a densidade nominal de 650 Kg.m-3, 12% de resina ureia formaldeído, 1% de parafina e ciclo de prensagem de oito minutos, com 160 ºC de temperatura e pressão máxima de 40 Kgf.cm-2. Para as propriedades físicas determinou-se o teor de umidade, densidade, razão de compactação, inchamento em espessura e absorção de água (2h e 24h). As propriedades mecânicas determinadas foram resistência a flexão estática, ligação interna, arrancamento de parafuso de topo e superfície. Com os resultados encontrados pode-se concluir que o aumento da porcentagem de resíduo de cevada diminui a resistência dos painéis para as propriedades físicas e mecânicas.

Industrial barley residue for the production of agglomerated panels / Resíduo de cevada industrial para a produção de painéis aglomerados

This work aimed to evaluate the physical and mechanical properties based panels made of barley industrial waste and particles Pinus spp. The company Bonet Woods and Papers Ltda. in the municipality of Santa Cecilia - Santa Catarina, provided the particles Pinus spp. The barley residue was provided by AMBEV in Lages, SC. For the production of panels used were five treatments, being composed of different barley residue content and particle Pinus spp.: 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4) and 0:100 (T5), to the residue and timber respectively. Three panels were produced per treatment, totaling 15 panels. The nominal density of 650 Kg.m-3, 12% of urea formaldehyde resin, 1% paraffin, eight minutes press cycle were used in the production of panels, with a temperature of 160 °C and a maximum pressure of 40 Kgf.cm-2. For the physical properties, moisture content, density, compression ratio, thickness swelling and water absorption (2h and 24h) were determined. The mechanical properties determined were static bending, internal connection, top and surface screw pulling. With the results found it can be concluded that increasing the percentage of barley residue decreases the resistance of the panels to the physical and mechanical properties.(AU)

Neste trabalho objetivou-se avaliar as propriedades físicas e mecânicas de painéis aglomerados constituídos por resíduos de cevada industrial e partículas de Pinus spp. As partículas de Pinus spp. foram fornecidas pela empresa Bonet Madeiras e Papéis Ltda. localizada em Santa Cecília, Santa Catarina. O resíduo de cevada foi fornecido pela AMBEV, Lages, SC. Para a produção dos painéis foram utilizados cinco tratamentos, sendo compostos por diferentes teores de resíduo de cevada e de partículas de Pinus spp., respectivamente: 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4) e 0:100 (T5). Foram produzidos três painéis por tratamento, totalizando 15 painéis. Na produção dos painéis, utilizou-se a densidade nominal de 650 Kg.m-3, 12% de resina ureia formaldeído, 1% de parafina e ciclo de prensagem de oito minutos, com 160 ºC de temperatura e pressão máxima de 40 Kgf.cm-2. Para as propriedades físicas determinou-se o teor de umidade, densidade, razão de compactação, inchamento em espessura e absorção de água (2h e 24h). As propriedades mecânicas determinadas foram resistência a flexão estática, ligação interna, arrancamento de parafuso de topo e superfície. Com os resultados encontrados pode-se concluir que o aumento da porcentagem de resíduo de cevada diminui a resistência dos painéis para as propriedades físicas e mecânicas.(AU)

Fusarium Mycotoxins Stability during the Malting and Brewing Processes.

Mycotoxins are widely studied by many research groups in all aspects, but the stability of these compounds needs further research for clarification. The objective of this study is to evaluate deoxynivalenol and zearalenone stability during all steps of the malting and brewing processes. The levels of these compounds decreased significantly during the production process (barley to beer). During the malting process, the DON levels decreased significantly in the steeping, germination, and malting steps (62%, 51.5%, and 68%, respectively). Considering ZEN, when the levels were compared between barley and the last step of the process, a significant decrease was observed. Most of the mycotoxins produced were transferred to the rootlets and spent grains, which is advantageous considering the final product. Furthermore, the mycotoxin dietary intake estimation was included in this study. The results proved that if the concentrations of target mycotoxins in raw material are under the limits established by the regulations, the levels decrease during the malting and brewing processes and make the beer secure for consumers. The quality of the five commodities involved in the beer process plays a decisive role in the creation of a safe final product.

[Synthesis and regulation of flavor compounds derived from brewing yeast: fusel alcohols]. / Síntesis y regulación de los compuestos del aroma y sabor derivados de la levadura en la cerveza: alcoholes superiores.

Among the main beer components, fusel alcohols are important because of their influence on the flavor of the final product, and therefore on its quality. During the production process, these compounds are generated by yeasts through the metabolism of amino acids. The yeasts, fermentation conditions and wort composition affect fusel alcohols profiles and their concentrations. In this review, we provide detailed information about the enzymes involved in fusel alcohols formation and their regulation. Moreover, we describe how the type of yeast used, the fermentation temperature and the composition of carbohydrates and nitrogen source in wort, among other fermentation parameters, affect the biosynthesis of these alcohols. Knowing how fusel alcohol levels vary during beer production provides a relevant tool for brewers to achieve the desired characteristics in the final product and at the same time highlights the aspects still unknown to science.

Key amino acid residues of the AGT1 permease required for maltotriose consumption and fermentation by Saccharomyces cerevisiae.

AIMS: The AGT1 gene encodes for a general α-glucoside-H+ symporter required for efficient maltotriose fermentation by Saccharomyces cerevisiae. In the present study, we analysed the involvement of four charged amino acid residues present in this transporter that are required for maltotriose consumption and fermentation by yeast cells. METHODS AND RESULTS: By using a knowledge-driven approach based on charge, conservation, location, three-dimensional (3D) structural modelling and molecular docking analysis, we identified four amino acid residues (Glu-120, Asp-123, Glu-167 and Arg-504) in the AGT1 permease that could mediate substrate binding and translocation. Mutant permeases were generated by site-directed mutagenesis of these charged residues, and expressed in a yeast strain lacking this permease (agt1∆). While mutating the Arg-504 or Glu-120 residues into alanine totally abolished (R504A mutant) or greatly reduced (E120A mutant) maltotriose consumption by yeast cells, as well as impaired the active transport of several other α-glucosides, in the case of the Asp-123 and Glu-167 amino acids, it was necessary to mutate both residues (D123G/E167A mutant) in order to impair maltotriose consumption and fermentation. CONCLUSIONS: Based on the results obtained with mutant proteins, molecular docking and the localization of amino acid residues, we propose a transport mechanism for the AGT1 permease. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results present new insights into the structural basis for active α-glucoside-H+ symport activity by yeast transporters, providing the molecular bases for improving the catalytic properties of this type of sugar transporters.

Síntesis y regulación de compuestos del aroma y el sabor derivados de la levadura en la cerveza: ásteres / Synthesis and regulation of flavor compounds derived from brewing yeast: Esters

Las levaduras, durante el proceso de elaboración de cerveza, producen más de 500 compuestos químicos; estos pueden impactar tanto negativa como positivamente en las características organolépticas de la cerveza. En los últimos años, y en particular gracias al avance de la biología molecular y la genómica, se han logrado progresos notables en el conocimiento de las bases moleculares y celulares de la síntesis y regulación de muchos de estos compuestos que inciden en lo que se denomina flavor (aroma y sabor) de la cerveza. Este artículo está enfocado en los ésteres responsables del aroma y el sabor floral y frutado de la cerveza. La formación de estos ésteres depende de diversas enzimas y de factores como la concentración de nutrientes presente en el mosto, la cantidad de oxígeno y dióxido de carbono disuelto, la temperatura de fermentación y, principalmente, la genética de la levadura utilizada. En esta revisión se brinda información de cómo se originan los ésteres y cómo los diferentes parámetros fermentativos impactan en las concentraciones finales de estos compuestos y en la calidad del producto terminado.

During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product.

Evaluación ergonómica del puesto de trabajo ayudante de mesa de baja presión en una empresa cervecera / Workstation ergonomic evaluation of alow pressure table assistant position in a brewery

Se realizó un estudio descriptivo, con enfoque ergonómico, para determinar riesgos de lesiones músculo-esqueléticas, en el puesto de trabajo "Ayudante de mesa de baja presión", en una empresa cervecera en la ciudad de Cagua, Venezuela. Diez hombres conformaron la muestra en la fase I, y dos en la fase II: bachilleres, sedentarios, 30,1 años de edad promedio, laborando en turnos rotativos de lunes a viernes, en las tareas: encajonar, quitar chapas, posicionar, arrumar, traslado y paletizar. Mediante entrevista personal y colectiva (utilizando la guía DEPARIS) se conocieron sus características socio-demográficas y opiniones respecto a problemas de salud, vinculados al puesto de trabajo. Los riesgos de lesiones músculo-esqueléticas fueron identificados con el método MODSI y Ecuación de NIOSH. Dicha evaluación indicó que en las tareas "encajonar, "quitar chapas", el riesgo es de nivel "medio", y en "posicionar", "arrumar", "traslado", y "paletizar", el riesgo es alto. En situaciones de "posicionar" y "traslado", fue considerado "muy alto", debido a factores como: bipedestación prolongada, movimientos de torsión de tronco, extensión de hombros, codos y brazos, lateralización de muñecas, flexión de espalda y cuello, y relativa fuerza. La organización del trabajo amerita cambios: aplicar un plan para disminuir las botellas rechazadas, diseñar herramientas de mano para destapar las botellas, instalar una silla para la alternabilidad de posturas, junto a un plan preventivo de trastornos músculo-esqueléticos, pausas activas y accidentes de trabajo, dotar de equipos de protección personal, ampliar los espacios de trabajo e incorporar ayuda mecánica adecuada a las características de las tareas y la necesidad de los trabajadores(AU)

We carried out a two-phase descriptive ergonomic evaluation of the low pressure table assistant job position in a brewery in Cagua, Venezuela to determine the risk of musculoskeletal injuries. There were 10 single men in phase I and two men in phase II, with an average age of30.1 years, working in rotating shifts from Monday through Friday. Tasks consisted of boxing, removing plates, positioning, cleaning up, transfers and palletizing. We used individual and group interviews (DEPARIS guide) to collect information on sociodemographic characteristics and opinions regarding job-related health issues. Risk of musculoskeletal injury was measured using the MODSI method and NIOSH Equation. This evaluation identified a medium risk for boxing and removing plates; it was high for positioning, arranging, moving, and palletizing. For tasks involving positioning and transfers, the risk was very high due to prolonged standing, trunk twisting, extension of the shoulder, elbow and forearm, lateralization of the wrists, back and neck flexion, and relative force. We also recommended some changes in how the work was organized. Among these implementing a plan to reduce rejected bottles, designing hand tools to open bottles, installing a multi-position chair to allow changes in posture, developing a preventive plan for musculoskeletal disorders, work breaks and accident prevention, providing personal protective equipment, expanding work spaces and incorporating mechanical assist devices appropriate to the characteristics of the tasks and worker needs(AU)

[Synthesis and regulation of flavor compounds derived from brewing yeast: Esters]. / Síntesis y regulación de compuestos del aroma y el sabor derivados de la levadura en la cerveza: ésteres.

During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product.

Phenolic compounds of Brazilian beers from different types and styles and application of chemometrics for modeling antioxidant capacity.

In the present study we aimed at investigating, for the first time, phenolic compounds in Brazilian beers of different types and styles. We also aimed at applying chemometrics for modeling beer's antioxidant capacity as a function of their physicochemical attributes (density, refractive index, bitterness and ethanol content). Samples (n=29) were analyzed by PCA originating five groups, especially according to ethanol contents and bitterness. In general, Group V (alcoholic beers with very high bitterness) presented higher refractive index, bitterness, ethanol and phenolics contents than Groups I (non-alcoholic beers) and II (alcoholic beers with low bitterness). Brazilian beers phenolics profile was distinct from that of European beers, with high contents of gallic acid (0.5-14.7 mg/L) and low contents of ferulic acid (0.2-1.8 mg/L). Using PLS, beer's antioxidant capacity measured by FRAP assay could be predicted with acceptable precision by data of ethanol content and density, bitterness and refractive index values.