Chemical characterization and antioxidant capacity in blue corn (Zea mays L.) malt beers

Corn has been widely used in traditionally fermented Mexican beverages. We recently developed a process to prepare beers using 100% pigmented corn varieties that provide polyphenols and anthocyanins with antioxidant properties. Moreover, new styles could be created when modifying the process conditions and ingredients. Thus, we explored the effect of caramel malt addition and different amounts of hops and guajillo chili, generating several styles of blue corn malt beers (BCMB). The objective was to evaluate these effects on selected chemical parameters and antioxidant properties at three different stages of the brewing process. To achieve this, base and caramel malts were obtained and used to develop eight styles of BCMB, using different concentrations of chili and hops, using an ale fermentation process. Eleven chemical properties were determined in the wort, green and mature beer of the eight styles of BCMB. Low‐alcohol beers were obtained and the values of total reducing sugars, alcohol, pH, total acidity, bitterness units and iso‐α ‐acids during the stages of the process were similar to barley beers. Additionally, anthocyanin concentration, polyphenols and antioxidant capacity decreased through the process stages. The interaction of the ingredients produced effects on the chemical composition and antioxidant activity in mature beers. After statistical analysis, by both univariate ANOVA and multivariate methods (hierarchical cluster analysis and principal component analysis), a higher concentration of anthocyanins and ABTS antioxidant capacity was founds in two beer styles that were formulated with 85% base malt and 15% caramel malt. Copyright © 2017 The Institute of Brewing & Distilling     

Physicochemical characterization of sahti,an ‘ancient’ beer style indigenous to Finland

Sahti, a strong, unhopped farmhouse beer flavoured with juniper, is still actively brewed in rural areas in Finland. Presented here is the first comprehensive analysis of the physical and chemical properties of this unique beer style. Twelve sahti samples from the southwest of Finland were analysed and, while properties varied, the beers generally had high levels of alcohol (mean = 7.9% ABV) and high residual extract (mean = 9.5°P). Foam stability was negligible, as is typical for the style, and glycerol concentrations at 3.1 – 4.7 g L^?1 were higher than in reference beers (commercial lager, wheat beer and porter). These features may be attributed to the very high gravity conditions employed in brewing sahti beers. Bitterness levels were relatively low (3–13 IBU) owing to the absence or moderate use of hops. All samples contained detectable levels of the clove‐like compound 4‐vinylguaiacol owing to the use of baker's rather than brewer's yeast for brewing. Concentrations of higher alcohols and esters were high, with many individual aroma compounds being above the normal flavour thresholds. Results have highlighted the uniqueness of this style of beer in comparison to commercially available beers and have contributed to our understanding of the reasons for the particular sensorial properties of this traditional beer style. Copyright © 2015 The Institute of Brewing & Distilling     

Beer fingerprinting by Matrix-Assisted Laser Desorption-Ionisation-Time of Flight Mass Spectrometry

A method allowing parallel fingerprinting of proteins and maltooligosaccharides directly from untreated beer samples is presented. These two classes of compounds were detected by Matrix-Assisted Laser Desorption-Ionisation-Time of Flight-Mass Spectrometry (MALDI-TOF-MS) analysis of beer mixed with 2,5-dihydroxybenzoic acid solution. The maltooligosaccharide profiles acquired from the MALDI sample spot center were not found characteristic for beers of different source and technology. On the other hand, according to profiles containing protein signals acquired from crystals formed on the border of the MALDI sample spot, we were able to distinguish beer samples of the same brand produced by different breweries. The discriminatory abilities of the method were further examined on a set of 17 lager beers, where the fingerprints containing protein signals enabled resolution of majority of examined brands. We propose MALDI-TOF-MS profiling as a rapid tool for beer brewing technology process monitoring, quality control, and determination of beer authenticity.     

Screening for new brewing yeasts in the non‐Saccharomyces sector with Torulaspora delbrueckii as model

This study describes a screening system for future brewing yeasts focusing on non‐Saccharomyces yeasts. The aim was to find new yeast strains that can ferment beer wort into a respectable beer. Ten Torulaspora delbrueckii strains were put through the screening system, which included sugar utilization tests, hop resistance tests, ethanol resistance tests, polymerase chain reaction fingerprinting, propagation tests, amino acid catabolism and anabolism, phenolic off‐flavour tests and trial fermentations. Trial fermentations were analysed for extract reduction, pH drop, yeast concentration in bulk fluid and fermentation by‐products. All investigated strains were able to partly ferment wort sugars and showed high tolerance to hop compounds and ethanol. One of the investigated yeast strains fermented all the wort sugars and produced a respectable fruity flavour and a beer of average ethanol content with a high volatile flavour compound concentration. Two other strains could possibly be used for pre‐fermentation as a bio‐flavouring agent for beers that have been post‐fermented by Saccharomyces strains as a consequence of their low sugar utilization but good flavour‐forming properties. Copyright © 2015 John Wiley & Sons, Ltd.     

Storage stability of pasteurized non‐filtered beer

The influence of pasteurization on non‐filtered beers was investigated during accelerated storage (40°C, 41 days). Two beers were produced from the same hopped wort, which was fermented with two different yeast strains. Half of the bottled beers were tunnel pasteurized resulting in four different beer samples. The pasteurization influenced the volatile profile of both fresh beers, but during storage the differences between the volatile profiles of pasteurized and non‐pasteurized beers disappeared. During the storage period, the pasteurized beers gave a lower rate of radical formation, as evaluated by electron spin resonance spectroscopy, indicating a better oxidative stability. The pasteurization had no effect on the levels of the pro‐oxidative metals iron and copper. Pasteurization slightly increased the protein content of the beers. SDS–PAGE analysis showed that the two beers had different protein profiles, which changed during storage; however, pasteurization of both beers did not affect their protein profiles. The level of thiols were lowered in one beer and raised in the other beer by pasteurization, but during storage the levels of thiols decreased at the same rate in all of the beers. It was concluded that pasteurization had a positive influence on the oxidative stability of non‐filtered beer. Copyright © 2013 The Institute of Brewing & Distilling     

Roasting of malt and xanthohumol enrichment in beer

The use of commercial roasted malts increases the content of the hop polyphenol xanthohumol (XN) in beer. This carrier effect is caused by high molecular melanoidins from roasted malt. Three roasting trials with different malts were performed in order to study the development of XN enrichment of wort and beer in laboratory and brewing trials. Different colour measurements, malt and flavour analysis, radical formation and antioxidative activity of selected samples were carried out. Furthermore, sensory tests of beers were conducted. During roasting the XN and isoxanthohumol enrichment in wort and beer rose with the roasting intensity of malt until it reached a maximum. The XN content in wort increased linearly with the colour of wort made from the malt samples. In PVPP-treated worts and in filtered beers, the XN content increased exponentially with the colour. After passing through a maximum, both the colour value and XN content in wort and beer decreased. Interestingly, the colour losses were more intensive than the losses of XN in worts and beers. The development of radical formation and the reducing power was linked during roasting. That means reducing groups of melanoidins are responsible for reducing power and prooxidative properties of malts. These functional groups of melanoidins are involved in the development of XN enrichment properties, because a linear correlation between these parameters was found. In conclusion, the roasting regimes showed potential for the development of special malt for the XN enrichment in beer- or malt-based beverages in late roasting stages. The use of this special malt brings more XN with less coloured malt in beer.     

Brewing with Rice Malt — A Gluten‐free Alternative

The preparation of beer‐like beverages with rice malt as the only raw material is reported. Several tests were performed on a laboratory scale and in a 25 L‐capacity pilot plant. Both the decoction and the infusion procedure were tested; malt and water were mixed in a ratio 1:3.5 for both methods and the mash was brewed without adding exogenous enzymes. The obtained worts were fermented using bottom fermenting yeasts, while “beers” were re‐fermented utilizing top fermenting yeasts and adding either sterile wort or sugar. A maximum ethanol of 4.5% vol. was obtained after the primary fermentation from an initial wort with an original gravity of 11.8°Plato. All parameters of the beer were found to be acceptable using a standard beer analysis. Owing to a suitable hop addition, an aroma very similar to that of a normal beer was obtained.     

Determination of Prolamins in Beers by ELISA and SDS‐PAGE

Coeliac disease is triggered by exposure to the prolamin protein fraction of wheat, barley, or rye. The prolamin content of five lager beers and one wheat beer were analyzed by sodium dodecyl sulfate—polyacrylamide gel electrophoresis (SDS‐PAGE) and immunoblotting and seven lager beers and three wheat beers were analyzed by enzyme‐linked immunosorbent assay (ELISA). Most of the lager beers were made from barley and some had varying amounts of rice or corn as adjuncts. One of the beers was “gluten‐free”, having been produced from corn and buckwheat without barley. The lager beer samples were gel‐filtered before ELISA or SDS‐PAGE analysis. Prolamin proteins were found in all but one beer which was made of corn, rice and barley and which was not the “gluten‐free” beer. ELISA analysis was done using a commercially available gluten assay kit. For lager beers, a barley prolamin standard for ELISA was propanol‐extracted from barley malt instead of using the prolamin standard of the gluten assay kit. As expected, the wheat beers contained much higher amounts of prolamins than the lager beers. The samples were studied by SDS‐PAGE to identify different prolamin fractions. Proteins having a relative molecular mass in the range of 8000–17,000 and 38,000 and above were detected in immunoblotting by the prolamin sensitive antibody in the lager beers.     

DETERMINATION OF TYRAMINE IN ALCOHOLIC AND NONALCOHOLIC BEERS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

A simple method for the isolation of tyramine from alcoholic and nonalcoholic beers and its subsequent analysis by HPLC with electrochemical detection has been developed. Ultrafiltration of the beer followed by a cation-exchange step provided clear resolution of the tyramine peak and greatly shortened the assay time. The concentration of tyramine in the alcoholic beers ranged from 0.98 to 3.21 mg L⁻¹ and in the nonalcoholic beers from 0.52 to 3.96mg L⁻¹. The possible hazard of consumption of both types of beer to patients on monoamine oxidase inhibitor treatment is discussed. The application of the method to the determination in other beverages is also demonstrated.     

Antioxidant properties of commercial alcoholic and nonalcoholic beverages

Recent interest in food phenolics has increased greatly, because of their antioxidant and free radical scavenging abilities. Popular beverages in the world include tea, coffee, cocoa, beer, wine and fruit/vegetable juices. All of these beverages contain phenolic compounds. In present study total polyphenol content and in vitro antioxidant properties were investigated in 16 red wines, 5 white wines, 5 lager beers, 3 dark beers, 17 fruit juices and 5 vegetable juices. High polyphenol content was measured in red wines (1720 +/- 546 mg x L(-1)) and in some fruit juices such as elderberry and prunes (5,680 and 1,807 mg x L(-1), respectively). The concentration of polyphenols was between 159 and 5,680 mg x L(-1) in fruit juices and between 255 and 696 mg x L(-1) in vegetable ones, while low level of phenolics was observed in dark and lager beers and white wines (473, 376 and 392 mg x L(-1), respectively). All samples exhibited significant antioxidant properties such as hydrogen-donating ability, reducing power, chelating ability and total antioxidant status (TAS) value. These antioxidant properties strongly correlated with the total polyphenol content of the beverages.     

PLSR modelling of quality changes of lager and malt beer during storage

The aim of this research was to create mathematical models for describing the changes in beer properties by using two chemometric methods applied on the experimental data. The models are intended to be useful and trustworthy for calculating four beer properties based on three easily measured ones. For that purpose, lager and malt beer were packaged in glass bottles, while lager beer was also packaged in polyethylene terephthalate (PET). Samples were placed at room temperature in the dark for 6 months. Fifteen physical and chemical properties of the beer were measured before bottling, immediately after bottling and once per month for the next 6 months. Standard MEBAK and Analytica‐EBC methods of analysis were applied. During the 6 month period, seven properties changed >1%. Two partial least squares regression methods [polynomial regression, partial least squares regression with polynomial regression (PLSR‐PR) and response surface method (PLSR‐RSM)] were used for modelling the relationships amongst multivariate measurements. Models with high statistical significance were determined and two PLSR methods were compared. Both chemometric methods were found to be suitable for modelling physical and chemical changes in the beers during their commercial shelf‐life. The PLS‐RSM method was found to be the more precise and confident method in describing property changes for lager and malt beer in glass bottles, while the polynomial regression model was found to be better for the lager beer packaged in PET. The R² values determined for polynomial regression model were up to 0.939, while for the random surface method model the values were up to 1.000. Copyright © 2016 The Institute of Brewing & Distilling     

Folate in Beer

Folate levels in a range of beers and other beverages have been measured using high‐performance liquid chromatography with fluorescence detection (HPLC‐FLD) and by liquid chromatography tandem mass spectrometry (LC‐MS/MS). The data from the LC‐MS/MS study was revealed to be unreliable, through the masquerading of polyphenol degradation products as folates. Using the HPLC‐FLD procedure most beers ranged between 2.2 and 24.2 μg per bottle, or up to 6.1% of the recommended daily allowance. Some imported beers contained no detectable folate and we believe that this is due to the folate decreasing in level during storage and transportation. Wine, vodka and whiskey contained no detectable folate, while orange juice contained folate at a comparable level to that found in the beer with the highest folate.     

Preference segments among declared craft beer drinkers: Perceptual,attitudinal and behavioral responses underlying craft-style vs. traditional-style flavor preferences

Craft beer is a product category that continues to expand, and craft beer drinkers are generally differentiated from traditional (or mainstream) beer drinkers in terms of their preference for innovative beers with novel and complex flavor profiles, and greater involvement in beer and product-focused behaviors and activities. The present research explores the existence of flavor-driven segments within the overall craft beer segment, where some declared craft beer drinkers exhibit the characteristic craft beer preference (stronger and more complex flavors), while others exhibit a preference for less complex and more traditional flavors. Research conducted with craft-style and traditional-style beers (n = 6) confirmed such preference segments in a group of male New Zealanders (n = 120). The preference segments perceived the sensory and holistic/conceptual characteristics of the beers similarly. However, they differed in specific attitudes and behaviors toward craft beers that were associated with the extent of their use and exposure to craft beers. The presence of the two preference segments was interpreted as being the result of a normal transition of declared craft beer drinker preferences away from the lighter flavors of the traditional style beers to which they had been accustomed and toward the more novel and robust flavors of craft beers. This shift in flavor preferences is tentatively attributed to the same exposure effects (mere and evaluative) that are responsible for flavor preference development in other foods and beverages. The implications for craft and traditional brewers are discussed and suggestions for future research presented.     

Free iron in pale, dark and alcohol-free commercial lager beers

BACKGROUND: A highly sensitive, selective, rapid, reliable and inexpensive method has been developed for the direct analysis of free iron in 40 samples of bottled lager beer. RESULTS: A differential pulse adsorptive stripping voltammetry technique at a hanging mercury drop electrode without any sample digestion was performed. The iron content in the analysed samples was in the range of 41 to 165 ppb. CONCLUSIONS: The results point out that dark beers keep the highest free iron concentrations, which may be related to the highest amounts of minor ingredients in dark beers. Meanwhile, alcohol‐free beers present the lowest free iron concentrations. Some discussion is presented regarding the basis of the free and complexed iron in beer and its participation as an essential element in the human diet. Copyright © 2011 Society of Chemical Industry     

A Comparison of the Antioxidant Potential of Wine and Beer

The antioxidant properties of two beers (an ale and a lager) and of two wines (a red Cabernet Sauvignon, and a white Chardonnay) have been compared using a range of assays: the Trolox assay, superoxide scavenging, hydroxyl scavenging and β‐carotene bleaching. When compared on an ‘as is’ basis, the red wine was shown to contain much more antioxidant potential than the other beverages with all the assays except the β‐carotene bleaching assay, which compares the ability of agents to prevent lipid oxidation. In this assay, beer performed best. When the beverages were compared on an equivalence of polyphenol basis, the superior performance of red wine was not evident, indeed white wine was the most potent in the Trolox assay and the superoxide scavenging tests, with beer again proving its superiority in the β‐carotene bleaching test. The study highlights the pitfalls of simply assuming that the superior performance of one product in a single assay means that it is inherently preferable as a source of antioxidants and pertinent issues remain the ability of the anti‐oxidants to access the tissues where they can exert a beneficial effect and the mode in which a substance needs to act in order to have a desirable impact on bodily health.     

Development of low-alcohol isotonic beer by interrupted fermentation

Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L⁻¹), osmolality (mOsmol kg⁻¹), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L⁻¹ gallic acid), reducing and total sugars (%) and Na and K contents (mg L⁻¹). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences.     

An investigation of matches of bottom fermented red beers with cheeses

This study was designed to explore the hedonic response of consumers to cheese and beer pairings by tasting in a typical social environment of consumption. Ninety-six regular beer and cheese consumers hedonically rated all fifty-six pairings of eight bottom fermented red beers and seven cheeses (Parmigiano Reggiano, Fontina, Taleggio, Smoked Provola, Mozzarella, Caprino, and Gorgonzola).Preference varied across samples (p < 0.001). One consumer out of two appreciated all of the pairings, yet pairings with Mozzarella were liked moderately. One consumer out of three appreciated pairings with Parmigiano, were neutral in their hedonic response to pairings with Fontina and disliked moderately the remaining pairings but those including mozzarella were extremely unappealing to them. One consumer out of six disliked all the pairings tested but some matches with Parmigiano were liked slightly. Liking of cheese and bottom fermented red beer pairings is biased by the type of cheese partnered with beer (Parmigiano most liked and Mozzarella least liked); by the type of beer partnered with cheese, and by the liking of the sensory properties of the beers and of the cheese tasted alone. However, consumers do not simply enjoy a combination of their most preferred beer and cheese. They identified some flavors that harmonize better than do others. Also, significant correlations between mean liking scores and sensory characteristics of the fifty-six pairings were found. Beer flavor is modified largely by prior cheese consumption. Each cheese has an effect on beer flavor and this effect is consistent over the eight different beers. In general all of the cheeses decreased the intensity of fruitiness, sweetness, perceived level of carbonation, perceived level of alcoholicity, caramel-like, licorice-like and burnt notes. Bitterness, astringency, and burnt notes were reduced by most of the cheeses but Fontina and Smoked Provola increased the perception of these attributes. For brewers to profitably exploit the potential of the science of cheese and beer pairing the choice of a suitable beer and of a suitable cheese in terms of liking and sensory properties and the identification of a proper target audience familiar to the beers paired with cheese are essential.     

Effects of “craft” vs. “traditional” labels to beer consumers with different flavor preferences: A comprehensive multi-response approach

Common definitions of craft-style beers emphasize that they are brewed by small, local breweries and that they have complex, novel and, often, bold flavors. In recent research conducted with declared craft beer drinkers who tasted beers in a blind condition, Jaeger et al. (2020) [FQAP, 103884] identified the existence of two preference segments. One segment (Craft-style Likers) preferred the characteristic complex, novel and bold flavors of many craft-style beers, while the other segment (Traditional-style Likers) preferred the less complex and milder flavors associated with traditional-style beers. In the present research, a multivariate response approach that included the evaluation of liking, sensory, holistic/conceptual, and cognitive/emotional/situational responses, as well as beer-related attitudes and behaviors, was used to assess the same set of six beers in a similar sample of declared craft beer drinkers (n = 122) as used in our previous study. However, beers were now labeled to reflect the style of the beer (craft vs. traditional) and the size (small vs. large) and regional origin (local vs. international) of the brewer. Results confirmed the existence of the same two preference segments. Although the effects of labeling the beers in accordance with their craft- vs. traditional-style natures did not influence sensory, holistic/conceptual or cognitive responses, they did influence emotional and situational responses. For craft-style beer likers, the information increased their positive emotions and the situational uses for craft-style beers, while for the traditional-style beer likers the labeling had a corresponding positive effect on their judgments of the traditional style beers. The results confirm previous findings on beer and product labeling, which show that sensory properties are less susceptible to extrinsic information effects than are affective, emotional and other, non-sensory product judgments. Implications for craft and traditional brewers are discussed and suggestions for future research presented.