Content In Beer Research Articles

Nitrogen Analysis in Beer Using a Zahm Custom Sample Bottle

Nitrogenated draft beer has been available for years and provides the consumer with an alternative to traditional draft beers. Accurate analysis of the nitrogen content in beer is needed to ensure the quality and consistency of the product. While both in-line and portable nitrogen meters are available, they are expensive. Furthermore, the use of a dedicated nitrogen analyzer adds another instrument to be maintained and calibrated. The use of Orbisphere packaged-beer analyzers (Orbisphere Laboratories, Neuchâtel, Switzerland) has become standard in many breweries for measuring total package oxygen and carbon dioxide. These instruments can also calculate nitrogen based on headspace partial pressure. The use of a laboratory instrument offers certain advantages in that it is more easily maintained and calibrated than are in-line instruments. However, when using a laboratory instrument, such as the Orbisphere, the accurate measurement of nitrogen in beer intended for draft dispense requires the presentation of a representative sample. This does present certain difficulties because of the insolubility of nitrogen in beer and the requirement of a headspace component in the sample. A solution to this problem was provided with the development of a modified Zahm bottle (Zahm & Nagel Company Incorporated, Holland, NY), fitted with a piston retraction mechanism to create package headspace. The newly developed nitrogen measurement procedure was evaluated for reproducibility and was compared with the results obtained using conventional analysis for non-carbon dioxide gas.

Tabulation of Alcohol Content of Beer and Malt Beverages

We present data from the analysis of the alcohol content of 391 beers and malt beverages available for sale in the State of Washington. The beverages were tested by gas chromatography for their alcohol content. Considerable variability in the alcoholic strength was found, even within the same class. Overall, the range of concentrations was 2.92% (v/v) to 15.66% (v/v). The alcohol content of beverages consumed is a critical factor in Widmark or volume-of-distribution-type calculations used to estimate blood or breath alcohol content from patterns of alcohol consumption. Using the correct alcohol content for beer, when the brand is known, can make a significant difference in the reliability of the calculation, and the data presented here should assist with optimizing the accuracy of the calculation.

Cognitive Restructuring as a Relapse Prevention Strategy

This research addresses the question of whether beer ads contain elements that directly tap into the psychological profile of recovering alcoholics, a special group whose needs have not been addressed by advertisers. The study examines the content of beer advertising for elements associated with problematic modes of experience previously identified for people addicted to alcohol. Results showed that beer ads contained appeals to all of these elements-a finding that suggests the persuasive strategy may be particularly compelling for alcoholics. Counter-strategies are offered that experts can implement in recovery programs to inoculate patients against the appeal of such ads, including teaching alcoholics to cognitively restructure advertising messages.

Inactivation of MXR1 abolishes formation of dimethyl sulfide from dimethyl sulfoxide in Saccharomyces cerevisiae.

Dimethyl sulfide (DMS) is a sulfur compound of importance for the organoleptic properties of beer, especially some lager beers. Synthesis of DMS during beer production occurs partly during wort production and partly during fermentation. Methionine sulfoxide reductases are the enzymes responsible for reduction of oxidized cellular methionines. These enzymes have been suggested to be able to reduce dimethyl sulfoxide (DMSO) as well, with DMS as the product. A gene for an enzymatic activity leading to methionine sulfoxide reduction in Saccharomyces yeast was recently identified. We confirmed that the Saccharomyces cerevisiae open reading frame YER042w appears to encode a methionine sulfoxide reductase, and propose the name MXR1 for the gene. We found that Mxr1p catalyzes reduction of DMSO to DMS and that an mxr1 disruption mutant cannot reduce DMSO to DMS. Mutant strains appear to have unchanged fitness under several laboratory conditions, and in this paper I hypothesize that disruption of MXR1 in brewing yeasts would neutralize the contribution of the yeast to the DMS content in beer.

Investigation of Mechanisms Governing Membrane Fouling and Protein Rejection in the Sterile Microfiltration of Beer with an Organic Membrane

Since the early 1980s, cold sterile crossflow microfiltration has been evaluated as a potential alternative to conventional thermal processes in the brewing industry (flash-or tunnel pasteurization). Up to now, industrial membrane development for beer microfiltration was limited both by severe membrane fouling and by protein and aroma compound retention. In the present work, fouling mechanisms and protein rejection have been investigated experimentally at laboratory scale for the microfiltration of a clarified (kieselguhr filtered) beer through a 0.2 mm polycarbonate membrane. Fouling mechanisms were analysed by using the constant pressure blocking filtration laws for which interactions arise between high molecular weight beer components and the membrane matrix resulting in pore constrictions and progressive blockage. Protein content in beer was measured using two dye-binding methods (Bradford and Lowry). It was found that permeate flux decay was governed by two successive fouling mechanisms: an internal pore fouling at the initial stages of filtration that conforms to the standard blocking model, followed by an external surface fouling conforming to the cake filtration model. The variation with time of membrane selectivity was characterized by a high initial protein transmission rate followed by a sharp decrease that occurs in a range of filtered volumes which is independent of the applied transmembrane pressure. For all experiments, protein retention level throughout the filtration was found to be closely related to the nature of fouling. It remains constant and low (<20%) in the presence of a pore diameter decrease induced by lateral adsorption of macrosolutes, then increases abruptly (up to 60%) and stabilizes when a fouling layer (gel layer) forms over the membrane surface. The significant role played in the composition of this limiting surface fouling layer by proteins (associated with polyphenols and b-glucans to form proteinaceous haze material) has been highlighted. The understanding of membrane fouling phenomena (such as the nature and location of fouling materials) is liable to lead to the design of efficient cleaning procedures for the sterile microfiltration of beer.

Prediction of the Formation of Frozen Beer Precipitates

The presence of frozen beer precipitates in packaged beer is a major consumer complaint, especially during cold winters. Therefore, it is important for brewers to predict the frozen stability of finished beer. The frozen stability of a packaged beer cannot be predicted by methods used to predict colloidal stability, such as the forcing test or alcohol-chilling test. To evaluate the frozen stability of canned beer, the freeze and thaw (F&T) cycle test was developed. We reproduced the change in outdoor temperature over 24 hr, which ranged from −2 to −12°C during winter, in a programmable incubator and measured the amount of precipitates formed. There was a large variation in the amount of frozen beer precipitates (F&T values) formed in commercial beers. Using this test, we found that two factors affect the frozen stability of beer. One factor is the composition of beer. The F&T value usually increased with an increase in the β-glucan content of beer. However, beer components such as α-glucan also greatly affected frozen stability. The other major factor affecting frozen stability is the practical freezing point of a packaged beer, which ranged from −7.1 to 13.8°C. We can determine the frozen stability of beer from these two factors and improve the visual quality of beer.

Anodic stripping voltammetry of copper at insonated glassy carbon-based electrodes: application to the determination of copper in beer

The suitability of ultrasound-assisted anodic stripping voltammetry (sono-ASV) for the detection of total copper content in beer using both mercury thin film and glassy carbon electrodes has been investigated. An immersion horn probe is introduced into a small thermostatted conventional three electrode cell (20 cm3) opposite the working electrode: an ex situ mercury plated Nafion®-coated mercury film electrode or a bare glassy carbon electrode. Minimal sample pre-treatment is required which consists of acidification of the beer with dilute nitric acid and out-gassing with argon. After the deposition of copper (as the metal or its amalgam) on the electrode in the presence of ultrasound, a square wave scan is employed to get the analytical signal. In the absence of ultrasound, electrode passivation by organic species and lower rates of mass transport prevent the observation of any measurable signals. In situ cavitational cleaning of the electrode by insonation maintains the electrode activity. Total copper content levels in the range of 100 to 300 µg Cu L–1 were determined by sono-ASV using both electrode substrates and showed excellent agreement with values provided by an independent method. This highlights the validity of the sono-ASV method as a useful electroanalytical technique in hostile media.

Effect of doubling fermentation method on sulfite content in beer

It was confirmed that sulfite content in beer brewed by doubling fermentation method was low. Sulfite content in beer brewed by doubling fermentation method was increased by the addition of unaerated wort but was not affected by pitching rate and intervals of wort addition. It seems that the addition of aerated wort during doubling fermentation method greatly affects the respiration system of yeast, leading to the decrease in sulfite content in beer.

Role of fermentation conditions on flavor stability of beer

To clarify the role of wort fermentation conditions on the stability of the resulting beer, the flavor stability of beers brewed at several fermentation temperatures (6–30°C) in a pilot brewing plant (30 l) was studied using chemiluminescence analysis. Chemiluminescence (CL) production in fresh and stored beers increased with fermentation temperatures. Flavor stability of the beers increased with decreasing fermentation temperatures. Sulfite content in the fresh beer decreased with an increase in fermentation temperatures. When sulfite was added to beer, the CL production in beers before and after storage decreased and the flavor stability increased with the concentration of sulfite. These data showed that it was an advantage for beer flavor stability to increase the sulfite level during fermentation. In this pilot study, the CL producing activity had a negative relationship with sulfite content in beer and with flavor stability, indicating that the CL producing pattern of beer is useful indicator for the evaluation of beer stability in the development of a more stable beer.

SCABA Method for Alcohol and Original Gravity Content in Beer

SCABA Method for Alcohol and Original Gravity Content in Beer

SCABA Method for Alcohol and Original Gravity Content in Beer

Click to increase image sizeClick to decrease image sizeAutomatedDistillationMethod comparison

SCABA Analyzer for Alcohol and Original Gravity Content in Beer

SCABA Analyzer for Alcohol and Original Gravity Content in Beer

SCABA Analyzer for Alcohol and Original Gravity Content in Beer

SCABA Analyzer for Alcohol and Original Gravity Content in Beer

Protein Content of Beer and Wort by Pyrochemiluminescence

The brewing industry normally estimates the total protein content of beer and wort by the Kjeldahl nitrogen method. This article describes an alternate method for determining total nitrogen and est...

Automated Procedure for the Estimation of Total Polyphenol Content in Beer, Wort, Malt, and Barley

An automated procedure using 4-aminoantipyrine as a chromogen was used to estimate total polyphenol content in beer, wort, malt, and barley. For 23 beers with a wide range in test results, the corr...

Automated Procedure for the Estimation of Total Polyphenol Content in Beer, Wort, Malt, and Barley

An automated procedure using 4-aminoantipyrine as a chromogen was used to estimate total polyphenol content in beer, wort, malt, and barley. For 23 beers with a wide range in test results, the correlation between the manual European Brewery Convention method and the automated method was 0.88. Barley and malt determinations were made on 30% aqueous dimethylformamide extracts of grain. Cultivar differences were found, suggesting the use of the procedure to select for polyphenol content in lines from barley breeding programs.

Zhodnotenie metód na stanovenie CO&lt;sub&gt;2&lt;/sub&gt; v pive.

Zhodnotenie metód na stanovenie CO&lt;sub&gt;2&lt;/sub&gt; v pive.

Methods for the Analysis of Beer

Abstract Four new methods relating to beer were released by the American Society of Brewing Chemists (ASBC) prior to their publication in t h e forthcoming revised edition of their book of methods. Three of these methods were subm i t t e d to t h e AOAC and were adopted as official first action: (1) cuprethol alternative method for the determination of copper in beer; (2) color of laboratory wort method to replace the present methods; ami (3) caloric content of beer as calculated from analytical data . The fourth method, “Accelerated Haze After Chilling,” was regarded as outside the field of general interest to the AOAC and therefore was not submitted for adoption. The methods proposed for adoption have been adopted as official first action.

RISK MANAGEMENT OF BEER FERMENTATION DIACETYL CONTROL

Diacetyl and 2, 3-pentandione are important contributors to beer flavor. These two compounds are grouped and reported as the vicinal diketone (VDK) content of beer. The removal of diacetyl is an important step in the maturation of beer. Diacetyl is formed by oxidative decarboxylation of ?-acetolactate. In the next step of fermentation, diacetyl is transformed to acetoin by enzymatic complex of the yeast. For flavor profile of beer it is very important that the concentration of VDK to be less than flavor threshold. In brewery pilot plant from USAMV Cluj-Napoca production trials were performed to monitoring any influence on beer quality and to optimize saving in time and cost.

Nutrient content of beers and ales.

THE pleasure of a draught of beer is doubted by few. Beer as a source of nutrients (for example, vitamins) or as a beverage low in nutrients (such as calories and sodium) has likewise been extolled, sometimes with accuracy, sometimes not. This report presents some of the facts concerning nutrient content of beer gleaned from the literature with the help of several groups from the brewing industry.1 2 3 4 5 6 7 8 Table 1 shows the nutrient content of beers and ales. Two ranges are given: that culled from the literature (mostly British, French and American) and a range for American brews when available. A rough mean . . .