Commercial Beers Research Articles

DNA authentication of brewery products: basic principles and methodological approaches

Beer DNA authentication is the process of authentication by identification of barley malt Hordeum vulgare or its substitutes, as well as hops and yeast. The method is based on molecular genetic analysis of residual quantities of nucleic acids extracted from the cellular debris of the final product. The aim of the study was to analyse scientific and methodical approaches to extraction of residual quantities of beer raw materials nucleic acids and beer DNA authentication for their later application in determining brewing products authenticity. The technological level discloses the method of DNA extraction from wines, modified for extraction of nucleic acids from beer samples. The method includes the following characteristic peculiarities: stage enzymatic hydrolysis of polysaccharides and polypeptides of dissolved lyophilisate, multiple sedimentation and resursuspension of nucleoproteid complex, RNA removal followed by DNA extraction by organic solvents, and additional DNA purification by magnetic particle adsorption. This review presents the analysis of genetic targets used as molecular markers for gene identification of malting barley varieties and beer DNA authentication. We also provided the interpretation of PCR analysis of Hordeum vulgare varieties and samples of commercial beer. Data on SSR- and SNP-markers of Hordeum vulgare nuclear DNA, used for barley varieties identification and potentially suitable for beer DNA authentication, are also presented. We also analysed genetic targets used in malting barley substitute detection, as well as hops and yeast identification in beer. Data on correlation of amplified DNA targets with beer quality indicators were systematised.

A Comparison of Single-Stage and Two-Stage Dry-Hopping Regimes

Multi-stage dry-hopping is a technique that is widely used by brewers to achieve intense hop aroma in beer. However, a thorough analysis of its efficacy does not exist in the published literature. The goal of this study was to compare the properties of beers produced by single or two-stage dry-hopping at the same cumulative rate. On the pilot scale (80–100 L), an un-hopped base beer was subjected alternately to single- or two-stage dry-hop additions at 386, 772, and 1544 g/hL using Centennial hops. Separately commercial beers (∼350 hL batch size) were dry-hopped at 733 g/hL in single or two-stage additions using a combination of Amarillo, Simcoe, Cascade, Citra, and CTZ pellets. Pilot scale dry-hopped beers showed increases in residual extract, pH, bitterness units, humulinones, and total polyphenols, accompanied by a decrease in iso-α-acids with increasing hop dose. Changes in bitterness units, humulinones, and iso-α-acids all appeared to be more pronounced in the two-stage dry-hopped beers. In contrast, commercial beers were nearly identical in terms of chemical composition. Significant increases in six aroma attributes scaled by a trained panel were observed as a result of two-stage dry-hopping in the pilot scale treatments. Slight increases in aroma potential were observed for the commercial beer made with two-stage additions, although these differences were not statistically significant. These results illustrate the impact multi-stage dry-hop additions have on beer aroma, and provide direction to brewers to consider whether multi-stage dry-hopping may yield desirable results while potentially using less hop material.

Assessing the internal standardization of the direct multi-element determination in beer samples through microwave-induced plasma optical emission spectrometry

An evaluation of different elements (Be, Ga, In, Sc, and Y) as internal standards was performed to determine the content of Al, Ba, Co, Cr, Cu, Fe, Mn, Ni, Sr, Zn, Ca, Mg, Na, K in beer samples through microwave induced plasma optical emission spectrometry. The analytes were determined after simple dilutions of the samples with a 1.0 M nitric acid solution at a 1:4 ratio (sample: acid solution) with the addition of the IS. The analytical performance for each potential IS was established based on the limit of detection, limit of quantification, addition and recovery tests and accuracy obtained in the determination of each analyte. Each analyte responded differently when internal standardization was applied, and as such, the evaluation of each IS is important in the development of the method. In the presence of the recommended internal standard, the limit of detection varied, in μg L−1, from 0.23 to 4.6 for the microelements and between 10 and 620 for the macroelements. The limit of quantification, in μg L−1, was between 0.78 and 15.4 and between 30 and 970 for the microelements and macroelements, respectively. The precisions of the measurements, expressed as the relative standard deviation (n = 10; 0.50 and 3.0 mg L−1 of each analyte), were lower than 1.0% for all analytes. The proposed method was applied for the multi-element determination in commercial beer samples and the results were compared with those obtained by inductively coupled plasma optical emission spectrometry after sample digestion.

Ice-bath assisted sodium hydroxide purification coupled with GC–MS/MS analysis for simultaneous quantification of ethyl carbamate and 12 N-nitrosoamines in yellow rice wine and beer

Ethyl carbamate (EC) and N-nitrosoamines (NAs) are toxic contaminants which can be typically formed in fermented alcoholic beverages. In the present work, a novel approach for simultaneous analysis of EC and NAs in beer and yellow rice wine based on ice-bath assisted sodiumhydroxide purification and GC–MS/MS was firstly established. Samples were extracted with acetonitrile-ethyl acetate after addition of internal standards. The extraction solution system was purified by sodiumhydroxide solid under ice-bath. After concentration, target analytes were separated on a HP-INNOWAX quartz capillary column and determined under dynamic multiple reactions monitoring mode of MS/MS. The limits of detection and quantification (LOD and LOQ), matrix effect, recovery and precision of the method were evaluated. Results were linear in the concentration range 2–200 μg/L for all analytes of interest, with regression coefficients higher than 0.999. LODs and LOQs were in the ranges of 0.1–0.5 μg/kg and 0.5–1.5 μg/kg, respectively. The mean recoveries at three spiked levels were between 81.5% and 121.0%. The intra- and inter-day precisions were in the ranges of 2.2–9.4% and 1.6–7.9%, respectively. The validated method was successfully applied to determine thirteen targets in commercial beer and yellow rice wine. EC was detected in all beers and yellow rice wines with the concentrations ranging from 1.18 to 22.90 μg/L. Results indicated wide EC contamination and confirmed its urgency for monitoring EC in fermented alcoholic beverages.

An accurate differential analysis of carboxylic acids in beer using ultra high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry based on chiral derivatization combining three isotopic reagents

We developed a highly sensitive and accurate differential method for analyzing chiral and achiral carboxylic acids in Japanese commercial beers, using ultra high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC–Q-TOF-MS), based on chiral derivatization combining three isotopic chiral reagents: 12C-DMT-3(S)-Apy, 13C2-DMT-3(S)-Apy, and d6-DMT-3(S)-Apy. By combining these reaction solutions and analyzing the resulting mixture, simultaneous comparative analyses of the three samples could be achieved while offsetting the matrix effects on the samples. Using this approach, it was possible to differentiate the beers according to the type (draft, low-malt, and non-alcoholic), manufacturer, and storage conditions (temperature and storage period), based on the concentrations of carboxylic acids in the beers. Furthermore, we identified α-ketoglutaric acid as a new marker for determining the storage condition of Japanese beers. The proposed method would provide insights into the identification of markers in various fields, such as in biological samples, as well as food and beverages.

Low-cost fluorescence-based method for beer bitterness measurement

A simple low-cost methodology for assessing beer bitterness using the IBU (International Bitterness Units) scale has been developed. The experimental setup is composed of a UV source, a fluorescent material and a digital single-lens reflex camera. The main concept of the method involves estimating the UV attenuation through IBU solution samples, by comparing the resulting fluorescence instead of the direct UV data obtained with a spectrophotometer. This significantly lowers the cost of the IBU measurement, allowing the hop bitterness values to be directly obtained from simple processing of the fluorescence images. For validation purposes, all values were compared to traditional measurements made with a spectrophotometer. A calibration procedure was carried out using samples with different iso-alpha-acid concentrations, which were naturally measured with the traditional IBU methodology. Finally, for illustrating the application of the novel method, commercial beers were analyzed using the traditional approach and compared with the proposed methodology. The results yielded a root mean square error of predicted samples below 3 IBUs, which demonstrates the potential of the proposed alternative.

English

Little or no attention has so far been paid to using sweet sorghum malt for commercial beer brewing. Thus, three sweet sorghum varieties (SSV) and four sorghum varieties (SV) were analyzed for brewing quality. Variations were observed in their thousand grain weights (22.8 to 58.7 g), grain moisture contents (12.5 to 20.5%), germination energies (99.0 to 100%) and germination capacities (99.7 to 100%). After 4-day germination, radicle lengths of seedlings were 2 to 5 fold of plumules. Remarkable variations existed in their water sensitivity (7.1 to 27.6%) and grain protein contents (7.0 to 11.8%). Malts moisture contents (8.6 to 13.8%), malting losses (16.3 to 26.0%) and malts protein contents (12.2 to 19.5%) differed among cultivars. Cold water extracts (CWE) (3.8 to 8.8%) and hot water extracts (HWE) (8.8 to 17.5%) varied with cultivars. HWE were 1.5 to 3-fold of CWE. Diastatic powers (DP) were substantially higher in SSV (123.7 to 136.7º) compared to SV (111.8 to 117º). Amyloglucosidase (AMG) activities were detected in SSV malts but not in SV. α-Amylases activities in both SSV and SV malts were about 2 to 4-fold of β-amylases. Generally, DP in SV malts = α-amylase + β-amylase activities. But DP in SSV malts >α-amylase + β-amylase + AMG activities, thus, suggesting synergism between the enzymes. SSV showed similar wort yields with SV. Reducing sugars in wort of SSV (12.3 to 15.6 mg/ml) were higher than those of SV (6.2 to 10.5 mg/ml). Malts and worts analyses suggest that SSV have greater beer brewing potentials than SV. Key words: Diastatic power, amylase, amyloglucosidase, sweet sorghum, malt, wort. &nbsp

Evaluation of Sequential-SBSE and TF-SPME Extraction Techniques Prior to GC-TOFMS for the Analysis of Flavor Volatiles in Beer

Sequential-Stir Bar Sorptive Extraction (Seq-SBSE) was investigated as a technique for the extraction and concentration of volatiles in beer prior to gas chromatography–time-of-flight mass spectrometry (GC–TOFMS) analysis for standard solutions prepared in an imitation beer solvent. Twenty-seven beer analytes across a range of polarities (Ko/w’s) were investigated. The technique provided acceptable quantitation for most of the 27 analytes investigated, but calibration curves for five of the most polar analytes were nonlinear. Thin Film SPME (TF-SPME) sample preparation, which has recently been shown to provide quantitative extraction of polar analytes, was compared to Seq-SBSE results for the standard solutions. TF-SPME provided linear calibration curves for all 27 analytes. To compare test precision, a commercial sample of beer was analyzed in triplicate by both techniques. Eighty-five analytes were detected by Seq-SBSE with an average percentage of relative standard deviation (%RSD) of 9.7% and 95 analytes were detected by TF-SPME with an average %RSD of 8.9%. Triplicate samples from three brands of commercial beers at the end of shelf life were analyzed. Ten potential off-flavor chemicals analyzed by TF-SPME were subjected to principal component analysis. Examination of principal component analysis (PCA) loadings results showed the most significant concentration differences in off-flavor chemicals in the different brands occurred with E-2-nonenal, 3-methyl-2-butene-1-thiol, and vinyl guaiacol. Studies showed that some analytes showed better detection sensitivity by Seq-SBSE, while other analytes were detected with higher sensitivity by TF-SPME. Linear least squares correlation coefficients for calibration curves were higher for Seq-SBSE except for highly polar volatiles, while TF-SPME was able to quantitatively detect more chemicals including highly polar ones. TF-SPME appears to be an excellent supplemental technique for the analysis of beer volatiles.

Non-starch polysaccharides in commercial beers on China market: Mannose polymers content and its correlation with beer physicochemical indices

Mannose polymers are important non-starch polysaccharides in beers. In this study, thirty-six beer samples representing three categories based on materials, including all barley malt beer, barley malt with adjuncts beer and wheat beer, were selected to investigate the content as well as its correlation with beer physicochemical indices, degree of polymerization, molecular weight and existent form of mannose polymers. The results suggested that mannose polymers level was significantly high in the wheat beer (156.76 mg/L and 456.50 mg/L calculated as mannan and glucomannan, respectively). Degree of polymerization was 23–47 and 46–162 calculated as mannan and glucomannan, and the molecular weight was 3,744 - 7,632 Da and 7,470 - 26,262 Da, respectively. Average ratio of glucose to mannose in glucomannan was between 1.79 and 1.93 without significant difference among three groups. Mannose polymers possibly exist in mannan, glucomannan or both. The content had significantly positive correlation with the original extract and viscosity of beers. Their correlation coefficients indicated more important influence on beer viscosity than β-glucan. This preliminary study would be helpful for revealing the structure of mannose polymers and its effect on beer brewing as well as human health.

Analysis of Seven Biogenic Amines and Two Amino Acids in Wines Using Micellar Electrokinetic Chromatography

A low-cost, simple, and fast method utilizing micellar electrokinetic chromatography for the simultaneous determination of seven biogenic amines and two amino acids was developed. A background electrolyte containing 5 mM phosphate buffer (pH 3.7) and 20 mM sodium dodecyl sulfate was used. The optimal separation of nine investigated analytes was achieved in 11 min, with limits of detection (S/N = 3) ranging from 0.11 to 0.61 µM. The linear ranges for all analytes were observed between 0.55 and 10.0 μM (R2 > 0.990). The developed approach was extended to the analysis of analytes in commercial wine and beer samples. The recoveries of the proposed method ranged from 98.8% to 115.6%.

Ultrathin Phthalocyanine-Conjugated Polymer Nanosheet-Based Electrochemical Platform for Accurately Detecting H2O2 in Real Time.

As a vital biological mediator and a widely used industrial oxidant, the accurate detection of hydrogen peroxide (H2O2) is of significance for both academic purpose and practical applications. Herein, we report a novel approach for the development of a high-performance electrochemical H2O2 sensor constructed by iron phthalocyanine (FePc)-based diyne-linked conjugated polymeric nanosheets (NSs), FePc-CP NSs. The FePc-CP NSs were delaminated from the bulk material via a defect- and disorder-induced synthetic strategy. By the quasi-Langmuir-Shäfer method, the prepared FePc-CP NSs were self-assembled into multilayer films with controllable thickness on electrodes. Owing to the highly exposed active centers on the surfaces, the FePc-CP NS film-modified electrodes exhibited excellent H2O2 determination performance with a wide linear detection range (0.1-1000 μM), a short response time (the response current approached the maximum value within 0.1 s), a low limit of detection (0.017 μM), and excellent sensitivity (97 μA cm-2 mM-1), which are comparable to the best results reported so far for electrochemical H2O2 sensors. In addition, the fabricated electrochemical H2O2 sensor also displayed satisfactory stability, reproducibility, and selectivity. Furthermore, the obtained FePc-CP NS film sensor can be applied in real-time monitoring of H2O2 in commercial orange juice and beer as well as H2O2 secreted from A549 live cells, revealing its application potential toward the accurate detection of H2O2 in real-sample analysis.

From cradle to chain? Gendered struggles for cassava commercialisation in Mozambique

ABSTRACT This article draws on survey data, interviews and archival research to analyse women's mixed responses to a cassava commercialisation scheme in Zavala district, Mozambique. As an example of the “Green Revolution for Africa” (GR4A) approach to development, which holds that women farmers’ participation in “value chains” will reduce rural poverty and hunger, this initiative seeks to transform cassava from a food staple into raw material for cassava-based commercial beer. The study evaluates the contradictory claims and outcomes of the GR4A model, as the bumpy roll-out of the value chain in Zavala reveals the risks of overlooking the historical context and gendered knowledge in neoliberal development interventions.

Atomic Layer Deposited TiO₂ and Al₂O₃ Thin Films as Coatings for Aluminum Food Packaging Application.

Titanium dioxide (TiO2) and aluminum oxide (Al2O3) coatings have been investigated in a wide range of bio-applications due to their biodegradation and biocompatibility properties, that are key parameters for their use in the food packaging and biomedical devices fields. The present study evaluates and compares the electrochemical behavior of the non-coated, commercial resin-coated, TiO2-coated and Al2O3-coated aluminum in commercial beer electrolyte. For this, TiO2 and Al2O3 thin films were deposited on aluminum (Al) substrates using atomic layer deposition (ALD). The evaluation of the corrosion barrier layer properties was performed by linear sweep voltammetry (LSV) during 10 min and electrochemical impedance spectroscopy (EIS). In addition, profilometry, grazing incidence X-ray diffractometry (GIXRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) analyses were performed to investigate the physical and chemical properties of the pristine and / or corroded samples. TiO2 and Al2O3 films presented an amorphous structure, a morphology that follows Al substrate surface, and a thickness of around 100 nm. Analysis of LSV data showed that ALD coatings promoted a considerable increase in corrosion barrier efficiency being 86.3% for TiO2-coated Al and 80% for Al2O3-coated Al in comparison with 7.1% of commercial resin-coated Al. This is mainly due to the lower electrochemical porosity, 11.4% for TiO2-coated Al and 20.4% for Al2O3-coated Al in comparison with 96% of the resin-coated Al, i.e. an increase of up to twofold in the protection of Al when coated with TiO2 compared to Al2O3. The EIS results allow us to complement the discussions about the reduced corrosion barrier efficiency of the Al2O3 film for beer electrolyte once SEM and FT-IR analyzes did not show drastic changes in both investigated ALD films after the corrosion assays. The above results indicate that ALD TiO2 and Al2O3 films may be a viable alternative to replace the synthetic resin coatings frequently used in aluminum cans of use in the food industry.

Novel paper-based electroanalytical tools for food surveillance.

Analytical strategies to ensure the quality and safety of food products without the need for skilled personnel are highly required. The simplicity of glucose strips for diabetes monitoring should be translated to the agri-food sector, ensuring easy evaluation of certain molecules and/or the freshness of a beverage/foodstuff. In addition to the well-known advantages that are characteristic of electroanalytical methods over other methods, paper-based materials are being used to further reduce the gap between complex laboratory testing and simple point-of-need testing. This article highlights some of the most recent advances in the development of paper-based electrochemical approaches for food surveillance, specifically focusing on the use of novel paper-based materials. Two examples are discussed: the development of a miniaturized biosensor realized on copy paper for the quantification of ethanol in commercial beers, and the measurement of ascorbic acid in food supplements within printed electronics supports. Paper-based materials have the potential to lower economic costs, simplify the operative tasks, and most importantly reduce waste generation. The continued combination of manufacturing methods and functional (smart) materials will facilitate the implementation of food analysis at the point of need.

The effect of consumption context on consumer hedonics, emotional response and beer choice

The context of a consumer test affects participant response. Data collected in a sensory laboratory is likely to have little predictive value of consumer experience in real-life situations. This study determined the effects of context on consumer response to two commercial beers. Regular beer consumers (n = 100) rated liking and emotional response using ten beer-specific emotion categories for two beers (Lager and Ale) under three different conditions: (1) a sensory testing facility (Lab), (2) a natural consumption environment (Bar) and (3) using an evoked context (Evoked). Their choice of product to take home was also recorded. Overall results showed significant product differentiation for liking (F (99, 2, 1) = 8.46, p = 0.004) and product choice (Q (1, N = 100) = 4.85, p = 0.028) in the Bar but not in the Lab or Evoked context. Emotional variables highlighted significant product differentiation (p < 0.05) but more so in the Bar than in the Lab or Evoked context. However, clustering participants on liking revealed three distinct clusters differing in sensitivity to context. Two clusters showed opposing but consistent preference for one of the two products regardless of context. The third cluster was more influenced by context, showing a more discriminating response in the Bar. These findings showed that consumers differ in their degree of context-sensitivity and the extent to which evoking a context gives similar results to a real environment. They also highlighted the importance of segmentation and confirmed the added insights gained by measuring emotional response compared to liking.

Comparaciones múltiples no paramétricas en la evaluación sensorial de la apariencia y sabor de tres marcas de cerveza comercial

Comparaciones múltiples no paramétricas en la evaluación sensorial de la apariencia y sabor de tres marcas de cerveza comercial Nonparametric multiple comparisons in sensory evaluation of appearance and flavor of three brands of commercial beer Carlos Minchón, Erika Mío y Kathy Córdova Universidad Nacional de Trujillo, cminchonm@gmail.com Universidad Nacional de Trujillo, firstkiss17@hotmail.com Universidad Nacional de Trujillo, kacese_4@hotmail.com DOI: https://doi.org/10.33017/RevECIPeru2011.0017/ RESUMEN La evaluación sensorial de los alimentos constituye una de las más importantes herramientas en la industria alimentaria. Las técnicas de evaluación sensorial aplicadas a quesos, embutidos, miel, agua, aceite de oliva y vino, también pueden ser empleadas en procesos de degustación con consumidores potenciales para conocer la percepción sobre las características organolécticas de productos en elaboración y productos comerciales, generándose la necesidad de difundir la aplicación de métodos estadísticos no paramétricos. El propósito del presente trabajo es determinar la marca de cerveza comercial con mejor apariencia y sabor empleando las pruebas no paramétricas de comparaciones múltiples. Las cervezas Pilsen Trujillo, Cristal y Brahma, marcas con importante aceptación en el mercado trujillano, fueron evaluadas sensorialmente en apariencia y sabor por 60 consumidores potenciales, usando escalas hedónicas de 5 puntos. Se aplicó la prueba de Friedman y pruebas de comparaciones múltiples, incluyendo pruebas considerando la cerveza Pilsen Trujillo. Los datos fueron procesados en IBM SPSS Statistics 19 y en EXCEL. La prueba de Friedman estableció diferencia tanto en la apariencia (p=0.000&lt;0.01) como en el sabor (p=0.000&lt;0.01) entre marcas, destacando Pilsen Trujillo en apariencia y Cristal en el sabor. Las pruebas de comparaciones múltiples evidenciaron similitudes de Pilsen Trujillo con Cristal en la apariencia (p&gt;0.05) y con Brahma en el sabor (p&gt;0.05), pero ambas por debajo de Cristal en cuanto al sabor. Se concluye que la cerveza Cristal es la mejor en sabor y similar en apariencia Pilsen Trujillo, pero superior a Brahma en ambos atributos. Además, la facilidad de aplicación de los métodos no paramétricos para comparaciones múltiples por rangos permiten extender su uso en la evaluación sensorial de productos tanto en proceso de elaboración como comerciales. Descriptores: evaluación sensorial, comparaciones múltiples, no paramétrico, cerveza. ABSTRACT The sensory evaluation of food is an important tool in the food industry. Sensory evaluation techniques applied to cheeses, cured meats, honey, water, olive oil and wine, can also be used in potential consumers tasting process to determine the perception of the organoleptic characteristics in elaboration of products and commercial products, generating the need to spread the application of nonparametric statistical methods. The purpose of this study is to determine the commercial beer brand with better appearance and flavor using nonparametric multiple comparisons. Trujillo Pilsen, Cristal and Brahma, brands with important acceptance in Trujillo market, were evaluated in appearance and flavor sensory for 60 potential customers using a 5-point hedonic scale. Was applied the Friedman test and multiple comparison tests and tests with a control, the control was Pilsen Trujillo beer. The data were processed by IBM SPSS 19 and Excel. Friedman test showed difference both in appearance (p = 0.000 &lt;0.01) and flavor (p = 0.000 &lt;0.01) between brands, Pilsen Trujillo in appearance and Cristal in flavor. Multiple comparison tests showed similarities between Cristal and Trujillo Pilsen beers in appearance (p&gt; 0.05) and with Brahma beer in flavor (p&gt; 0.05), both inferiors to Cristal in flavor. Was conclude that Cristal beer is the best in flavor and similar in appearance with Pilsen Trujillo, but higher than Brahma in both attributes. Furthermore, the ease application of nonparametric methods for multiple comparisons by ranks, let us to extend its use in sensory evaluation in elaboration of products and commercial products. Keywords: sensory evaluation, multiple comparisons, nonparametric, beer

Universal existence of fluorescent carbon dots in beer and assessment of their potential toxicity

Nanosized materials may produce adverse physiological effects or potential health risks due to their unique physical and chemical properties. Herein, the universal presence of fluorescent carbon dots (CDs) in commercial beers was confirmed through a systematic survey. The beer CDs were roughly spherically shaped in appearance and emitted bright blue fluorescence under ultraviolet light with quantum yields (QYs) ranging from 1.42% to 3.92%. Furthermore, digestion, biodistribution, and cytotoxicity assessments of CDs from Snow beer were conducted as an example. The CDs were significantly quenched during in vitro digestion. The dynamic distribution of CDs in mice showed that they easily accumulated in the intestine and liver, and more importantly, the beer CDs were found in the brain, which indicated that they were able to cross the blood–brain barrier. Acute toxicity of the beer CDs was evaluated using BALB/c mice, and the results revealed that the biochemical parameters of mice after administration of a single dose of 2 g kg−1 body weight were almost same as those of the control groups. Histological analysis showed no obvious organ damage in the tested mice. The in vitro results indicated that CDs dispersed onto both the cell membrane and the cytoplasm of MC3T3-E1 cells, alter the cell cycle progression, and caused cell apoptosis at high doses. This work reports the potential risk of CDs in beer and provides valuable information regarding CDs in food.

Valoración y uso de una nueva variedad de cebada para elaboración de cerveza artesanal

Introduction: In recent years the brewing industry has shown great growth, which makes it necessary to generate knowledge about the use of new varieties of barley produced in Mexico. Objective: To evaluate the potential of Dona Josefa barley to brew gourmet-type beer with different flavor notes according to the type of malt. Methodology: Five malts were prepared: Pilsen, Vienna, Melano, Cafe and Chocolate. Their diastatic power, concentration of total and reducing sugars and content of β-glucans were analyzed. Subsequently, Pilsen was mixed with each of the other malts to obtain beer worts, from which different craft beers were brewed and later physically evaluated and compared sensorially with commercial beers. Results: Pilsen malt had the highest concentration of total sugars (67.09 g∙100 g-1 malt) and Melano the lowest (24 g∙100 g-1 malt). Vienna malt had the lowest diastatic power. The beers showed an alcohol content between 4 and 7 %, associated with the pH trend. Sensorially, only the Cafe and Chocolate beers were accepted by consumers. Study limitations: Only one type of fermentation (lager) and one strain of yeast were used. Originality: Dona Josefa barley is a new variety that has greater resistance to disease and is slightly larger than those currently used to produce beer. Conclusions: The malting provided suitable conditions for making different brewing malts from the Dona Josefa barley. The malts had total and reducing sugar values appropriate for brewing beers. Chocolate beer had the same level of acceptance as a commercial beer.

Isolation and molecular identification for autochthonous starter Saccharomyces cerevisiae with low biogenic amine synthesis for black raspberry (Rubus coreanus Miquel) wine fermentation.

Biogenic amines (BAs) are widely present in nearly all fermented foods and beverages, and excess consumption can cause adverse health effects. To prepare BA-free Korean black raspberry wine (BRW), four autochthonous starter yeast strains without hazardous BA synthesis activity were selected and their physiological and biochemical properties were examined. The selected strains were identified as Saccharomyces cerevisiae based on 26S rDNA sequencing and microsatellite analysis. Molecular fingerprinting revealed that isolates were quite different from commercial wine yeast S. cerevisiae (52.4% similarity), but genetically relevant to commercial beer yeasts. The four S. cerevisiae strains produced over 10% ethanol during BRW fermentation. In addition, the fermented BRW with these strains showed higher levels of total flavonoids and similar antioxidant activity compared to the control sample. Potentially hazardous BAs that commonly occur in black raspberry extract (BRE) such as cadaverine, histamine, and spermidine were also not detected in the fermented BRW. Thus, we suggest that our strains are promising fermentation tools to ensure high quality and enhanced functionality in the production of BA-free BRW.

Screening the Lactic Acid Bacteria converting Hydroxy Fatty Acid from Unsaturated Fatty Acid.

Hydroxyl fatty acids (HFAs) are used in widely diverse industrial applications, healthy functional foods, artificial food flavorings, and alcoholic beverages. A lactic acid bacterium (LAB), Lactobacillus sakei, hydroxylates oleic acid. Furthermore, the hydroxyl fatty acid was identified by GC-MS as 10-hydroxystearic acid. The Lactobacillus sakei hydroxylated more than 90% of the oleic acid in the medium at 15°C after 30-48h. The hydroxyl enzyme needs a coenzyme for an electron donor as NADPH. The enzyme is useful for assay with monitoring NADPH concentration used an A340 device. The hydroxylate fatty acids converted by LAB lactonize aroma lactone from commercial yeast strains, which can be detected directly by scent. Commercial beer brewing yeast T-58 produced the highest concentration of aroma lactone from hydroxyl fatty acids. Furthermore, the aroma lactone is identified by GC-MS as gamma-dodecalactone. The ratio of conversion is 87%. These results suggest that the lactonization conversion system is useful to hydroxylate fatty acids for alcoholic beverages.