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

Assessment of the impact of unmalted cereals, hops, and yeast strains on volatolomic and olfactory profiles of Blanche craft beers: A chemometric approach

This study investigated the impact of changes in craft beer formulation, by modifying the unmalted cereal [(durum (Da) and soft (Ri) wheat), emmer (Em)], hops [Cascade (Ca) and Columbus (Co)], and yeast strains [M21 (Wi) - M02 (Ci)], on volatolomic, acidic, and olfactory profiles. Olfactory attributes were evaluated by the trained panel. Volatolomic and acidic profiles were determined by GC-MS. The sensory analysis detected significant differences for 5 attributes, including olfactory intensity and finesse, malty, herbaceous, and floral notes. Multivariate analysis of volatiles data, showed significant differences among the samples (p < 0.05). DaCaWi, DaCoWi, and RiCoCi beers differ from the others by their higher concentrations of esters, alcohols, and terpenes. A PLSC analysis was carried out between volatiles and odour attributes. As far as we know, this is the first investigation that shed light on the impact of 3-factors interaction on the sensory-volatolomic profile of craft beers, through a comprehensive multivariate approach.

Jambu Flower Extract (Acmella oleracea) Increases the Antioxidant Potential of Beer with a Reduced Alcohol Content

Craft beers with different sensory perceptions have received the attention of more demanding consumers. In this sense, the application of plant extracts as brewing adjuncts is being increasingly studied. Allied with these perspectives is the consumption of lower alcoholic beverages, which also represents the desire for a market niche that has been growing gradually. The present work aimed to produce craft lager beer with the addition of plant extract and reduced alcohol content by partial replacement of malt with malt bagasse. The physical-chemical analyzes of the beer produced showed that it was possible to reduce the alcohol content by 40.5% compared to the control sample. In addition, an extract of Acmella oleracea (Jambu) obtained by supercritical extraction was added to increase the beer's antioxidant capacity. The ABTS, DPPH, and ORAC methods evaluated the antioxidant capacity. These assays were performed again after six months of storage. The quantification and identification of the significant substance in the extract (spilanthol) were performed using Gas Chromatography (GC-FID), Thin Layer Chromatography (TLC), and Attenuated Total Reflectance Infrared Spectroscopy (FTIR-ATR). The results showed significant increases in antioxidant activity compared to the sample without extract. This positive aspect opens a perspective for using jambu flower extract as a prominent antioxidant adjunct in beer.

The Phenolic Compounds' Role in Beer from Various Adjuncts

BACKGROUND

The present article considers the influence of malt with various adjuncts on beer organic compounds and taste profile composition, with more attention paid to the phenol complex change. The topic under consideration is relevant since it studies the interactions of phenolic compounds with other biomolecules, and expands the understanding of the adjuncts organic compounds contribution and their joint effect on beer quality.

METHODS

Samples of beer were analyzed at a pilot brewery using barley and wheat malts, barley, rice, corn and wheat, and then fermented. The beer samples were assessed by industry-accepted methods and using instrumental analysis methods (high-performance liquid chromatography methods-HPLC). The obtained statistical data were processed by the Statistics program (Microsoft Corporation, Redmond, WA, USA, 2006).

RESULTS

The study showed that at the stage of hopped wort organic compounds structure formation, there is a clear correlation between the content of organic compounds and dry substances, including phenolic compounds (quercetin, catechins), as well as isomerized hop bitter resines. It is shown that the riboflavin content increases in all adjunct wort samples, and mostly with the use of rice-up to 4.33 mg/L, which is 9.4 times higher than the vitamin levels in malt wort. The melanoidin content in the samples was in the range of 125-225 mg/L and its levels in the wort with additives exceeded the malt wort. Changes in β-glucan and nitrogen with thiol groups during fermentation occurred with different dynamics and depending on the adjunct's proteome. The greatest decrease in non-starch polysaccharide content was observed in wheat beer and nitrogen with thiol groups content-in all other beer samples. The change in iso-α-humulone in all samples at the beginning of fermentation correlated with a decrease in original extract, and in the finished beer there was no correlation. The behavior of catechins, quercetin, and iso-α-humulone has been shown to correlate with nitrogen with thiol groups during fermentation. A strong correlation was shown between the change in iso-α-humulone and catechins, as well as riboflavin and quercetin. It was established that various phenolic compounds were involved in the formation of taste, structure, and antioxidant properties of beer in accordance with the structure of various grains, depending on the structure of its proteome.

CONCLUSIONS

The obtained experimental and mathematical dependences make it possible to expand the understanding of intermolecular interactions of beer organic compounds and take a step toward predicting the quality of beer at the stage of using adjuncts.

Evaluation of the antioxidant characteristics of craft beer with green tea

The addition of green tea as antioxidants to beer can improve the beer's flavor stability by protecting against staling during storage. To analyze the effect of different green teas on the flavor stability of beer, we developed an approach to rapidly evaluate their antioxidant activity. Ten types of craft beer were produced by adding different kinds of green tea during brewing, and their antioxidant activity and phenolic profiles were evaluated. The results showed remarkable variations in antioxidant activity and antioxidative compound contents, which were considerably higher in green tea beers than in non-tea beer (p < 0.05). A comprehensive evaluation function was developed to evaluate the total antioxidant activity of beers using principal component analysis. The highest total antioxidant activity was observed in Taiping Houkui beer, with a comprehensive evaluation score of 2.53. Pearson correlation analysis suggested that (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (-)-epigallocatechin were strongly correlated with the total antioxidant activity of green tea beers (p < 0.01). The summation of their contents represented more than 60% of the total phenolic content of the teas, which can be used to predict the total antioxidant activity of green tea beers. PRACTICAL APPLICATION: Flavor stability is of prime concern for brewers, and flavor aging is increasingly becoming the limiting factor in beer shelf life. The application of green tea as antioxidants in beer can improve the flavor stability by protecting against beer staling during storage. The analytical method developed in this study will contribute to the rapid comparison of the effect of different green teas on the flavor stability of beer. Furthermore, the research findings demonstrate the potential benefits of green teas to beer flavor stability, which is of considerable importance in promoting the development and consumption of green teas.

Commercial craft beers produced in Uruguay: Volatile profile and physicochemical composition

Even beer being the most consumed alcoholic beverage around the world, there is not enough information generated for craft beers produced in Latin America, for either volatile profiles or physicochemical studies. In this work, the chemical and volatile components of ten commercial Blond Ale and nine Indian Pale Ale (IPA) beers from the Uruguayan market were studied using GC-MS. Principal component analysis applied to the data allowed differentiation among the two groups of samples while the volatile compounds and physicochemical parameters responsible for these differences were identified. The physicochemical properties revealed a great diversity between all beer samples even within the same beer style. The main significant differences were obtained for alcohol, polyphenols, bitterness, colour, and pH. Most Blond Ale beer samples were differentiated from IPA ones by raw fermentation aroma compounds such as 1-pentanol, 1-hexanol, hexanoic and isobutyric acids, 4-vinyl guaiacol, and 5,5-dimethyl-2(5H)-furanone. This is the first work that contributes to the knowledge of Uruguayan craft beers. The study also showed the ability of most of the Uruguayan microbreweries to brew Blond Ale and IPA craft beer styles that meet international standards for physicochemical quality.

Physicochemical Properties and Antioxidant Activity of Portuguese Craft Beers and Raw Materials

There is an increase in the popularity of craft beer, which is produced by small, independent, and traditional breweries. Since craft beer popularity is rising in Portugal this research focused on assessing physicochemical parameters, total phenolic content (TPC) and the antioxidant capacity of Portuguese craft beers and raw materials used in beer production. In this experimental study, 19 beer samples were analyzed. Parameters such as pH, Total Acidity, Reducing Sugar Content and TPC were evaluated. For the determination of antioxidant activity, DPPH scavenging activity and metal chelating activity (MCA) were analyzed in all samples. Craft beers demonstrated a high phenolic content (ranging from 343.78 mg GAE/L to 2172.49 mg GAE/L), significantly different from industrial beers. Craft beers demonstrated a higher inhibition of DPPH radicals and higher MCA than the raw materials. DPPH inhibition ranged from 36.5% to 96.0% for malt and 64.7% to 79.6% in hops samples. MCA also varied between the different samples, with results of 12.0% to 24.8% in malt samples and 3.8% to 23.5% in hops. Raw materials can potentially influence the antioxidant activity of the resulting beer. Positive correlations between TPC and physicochemical properties can be useful to help consumers choose beers with added value for health.

Fabrication of a donkey spleen ferritin-pectin complex to reduce iron release and enhance the iron supplementation efficacy

Iron deficiency is a global issue, influencing more than one-third of the population in the world. Ferritin as a natural iron-containing protein is considered a marvelous iron supplement due to its biocompatibility, biodegradability and bioavailability. However, foodstuffs contain plenty of reductants which could induce iron release from the cavity of ferritin and cause oxidative damage. In this study, we aimed to prevent the iron release from donkey spleen ferritin (DSF) by pectin encapsulation driven by the electrostatic interaction and evaluated the iron supplementation of the DSF-pectin complex (DPC). After DSF was purified, we fabricated the DPC and the iron release was decreased by 53.68% after 60 min when DSF : pectin was 1 : 10 (w/w). TEM analysis showed that ferritin in the DPC is clustered in a linear pattern, and the cell viability assay indicated that the DPC has no toxicity towards Caco-2 cells. In the mouse experiment, the DPC increased the content of serum iron and serum ferritin with no significant difference from the control check. Furthermore, the DPC increased the iron content in the liver, suppressed the expression of hepcidin and increased the expression of ferroportin. These results suggested that the DPC could prevent the interactions between food components and ferritin and is a promising iron supplement to ameliorate iron deficiency.

New Approaches for the Fermentation of Beer: Non-Saccharomyces Yeasts from Wine

Non-Saccharomyces yeasts represent a very attractive alternative for the production of beers with superior sensory quality since they are able to enhance the flavour of beer. Furthermore, they can produce beers with low ethanol content due to the weak fermentative capacity of a large percentage of non-Saccharomyces species. The objective of this study was to evaluate the ability of 34 non-Saccharomyces yeast strains isolated from Madrilenian agriculture to produce a novel ale beer. The non-Saccharomyces yeast strains were screened at two scales in the laboratory. In the first screening, those with undesirable aromas were discarded and the selected strains were analysed. Thirty-three volatile compounds were analysed by GC, as well as melatonin production by HPLC, for the selected strains. Thirteen strains were then fermented at a higher scale in the laboratory for sensory evaluation. Only yeast strains of the species Schizosaccharomyces pombe and Lachancea thermotolerans were able to complete fermentation. Species such as Torulaspora delbrueckii, Metschnikowia pulcherrima, Wickerhamomyces anomalus, Hanseniaspora vineae, and Hanseniaspora guilliermondii could be used both for production of low ethanol beers and co-fermentation with a Saccharomyces yeast to improve the organoleptic characteristics of the beer. In addition, for these strains, the levels of melatonin obtained were higher than the concentrations found for Saccharomyces strains subjected to the same study conditions. The selected strains can be used in future trials to further determine their viability under different conditions and for different purposes.

Amylolytic Fungi in the Ethnic Beer Starter “emao” and Their Beer-Producing Attributes

Naturally occurring autochthonous microbes associated with ethnic beer starters are diverse and important as they play different functional roles in beer fermentations. The study on culturable microbes from the ethnic rice beer starter “emao” of the Bodo community of Assam is limited. Here we isolated and identified the culturable fungal diversity associated with emao and screened them for beer-producing capability from glucose and starch substrates. Based on morphology and molecular characterization, the species identified were Candida glabrata (Cgla_RF2), Cyberlindnera fabianii (Cfab_RF37), Hyphopichia burtonii (Hbur_RF19), Mucor circinelloides (Mcir_RF48), Mucor indicus (Mind_RF25), Penicillium citrinum (Pcit_RF32), Rhodosporidiobolus ruineniae (Rrui_RF4 &amp; Rrui_RF43), Saccharomyces cerevisiae (Scer_RF6), Saccharomycopsis fibuligera (Sfib_RF11), and Wickerhamomyces anomalus (Wano_RF3) among which the relative abundance (RA) of W. anomalus was the highest (24%) followed by C. glabrata and H. burtonii (16% in each). Five (Hbur_RF19, Sfib_RF11, Mind_RF25, Mcir_RF48, and Pcit_RF32) of eleven isolates showed amylase positive in the starch medium. Scer_RF6 showed the highest ethanol tolerance (14% v/v) followed by Hbur_RF19 (12% v/v), Cgla_RF2 (11% v/v) and Wano_RF3 (11% v/v). The amylase-positive strains produced beer-containing ethanol in the range of 3.17–7.3 (% v/v) from rice substrate. Although the rice beer produced by amylase-positive strains showed negligible pH difference, other parameters like ethanol, ascorbic acid, total phenol, and antioxidant properties were varied from beer to beer. Antibacterial activities shown by Mcir_RF48 and Pcit_RF32 against the test bacteria were higher with a 23–35 mm zone of inhibition than the other isolates. The present findings reveal the presence of fungi with antibacterial, amylolytic, ethanol fermenting, and antioxidant producing capacity in emao which could the source for future bioprospection.

A review on the fate of phenolic compounds during malting and brewing: Technological strategies and beer styles

This review provides an overview on the influence of malting and brewing on the overall phenolic content of barley malt and beer. Beer phenolics are mainly originated from barley malt and can be found in free and bound forms, in concentrations up to 50% lower comparing to sweet wort. The use of roasted malts, in combination with proper milling and high mashing temperatures at low pH can lead to a release of bound phenolic forms and increased extraction. New technological strategies such as special yeasts, manipulation of enzymatic activity and dry-hopping may be relevant to improve the phenolic profile of beer and attain phenolic levels with benefits both for beer stability and consumer's health. As the content of free ferulic acid in beer only accounts up to approximately 15% of total content, further studies should put emphasis on its bound forms in different beer styles and non-alcoholic beers.

Bioactive Compounds from Pale Ale Beer Powder Attenuate Experimental Colitis in BALB/c Mice

Phenolic compounds (PCs) present in foods are associated with a decreased risk of developing inflammatory diseases. The aim of this study was to extract and characterize PCs from craft beer powder and evaluate their potential benefits in an experimental model of inflammatory bowel disease (IBD). PCs were extracted and quantified from pure beer samples. BALB/c mice received either the beer phenolic extract (BPE) or beer powder fortified with phenolic extract (BPFPE) of PCs daily for 20 days by gavage. Colon samples were collected for histopathological and immunohistochemical analyses. Dextran sodium sulfate (DSS)-induced mice lost more weight, had reduced colon length, and developed more inflammatory changes compared with DSS-induced mice treated with either BPE or BPFPE. In addition, in DSS-induced mice, the densities of CD4- and CD11b-positive cells, apoptotic rates, and activation of NF-κB and p-ERK1/2 MAPK intracellular signaling pathways were higher in those treated with BPE and BPFPE than in those not treated. Pretreatment with the phenolic extract and BPFPE remarkably attenuated DSS-induced colitis. The protective effect of PCs supports further investigation and development of therapies for human IBD.

Gallic Acid Mitigates 5-Hydroxymethylfurfural Formation while Enhancing or Preserving Browning and Antioxidant Activity Development in Glucose/Arginine and Sucrose/Arginine Maillard Model Systems

The current trend of lowering 5-hydroxymethylfurfural (5-HMF) dietary exposure is challenging since its formation is parallel with the development of food color, flavor and aroma. We aimed to investigate the effect of gallic acid (GA) addition on 5-HMF formation, color development and antioxidant activity (AA) in a series of Maillard Reaction (MR) model systems. The effects of GA addition on browning and AA development were not uniform for all model systems, but always occurred in the same direction, indicating that these phenomena were interconnected. GA mitigated 5-HMF development in four of the nine tested systems, possibly by preventing the oxidation of MR intermediates. Correlation analysis indicated that when GA addition mitigated 5-HMF formation, browning was either promoted or not affected. The proposed strategy was effective for glucose/arginine and sucrose/arginine systems, since GA mitigated 5-HMF formation (49% and 54%, respectively) in addition to increasing color development and antioxidant activity.

The Influence of Biomolecule Composition on Colloidal Beer Structure

Recent studies have revealed an interest in the composition of beer biomolecules as a colloidal system and their influence on the formation of beer taste. The purpose of this research was to establish biochemical interactions between the biomolecules of plant-based raw materials of beer in order to understand the overall structure of beer as a complex system of bound biomolecules. Generally accepted methods of analytical research in the field of brewing, biochemistry and proteomics were used to solve the research objectives. The studies allowed us to establish the relationship between the grain and plant-based raw materials used, as well as the processing technologies and biomolecular profiles of beer. The qualitative profile of the distribution of protein compounds as a framework for the formation of a colloidal system and the role of carbohydrate dextrins and phenol compounds are given. This article provides information about the presence of biogenic compounds in the structure of beer that positively affect the functioning of the body. A critical assessment of the influence of some parameters on the completeness of beer taste by biomolecules is given. Conclusion: the conducted analytical studies allowed us to confirm the hypothesis about the nitrogen structure of beer and the relationship of other biomolecules with protein substances, and to identify the main factors affecting the distribution of biomolecules by fractions.

Wine Saccharomyces Yeasts for Beer Fermentation

Multiple studies in recent years have shown the potential of Saccharomyces wild yeasts to produce craft beers with new flavour profiles and other desirable properties. Yeasts isolated from food (wine, bread, kombucha…) have shown potential promise for application in brewing. The aim of this study is to evaluate the ability of 141 Saccharomyces yeast strains isolated from the Madrilenian agriculture (from grapes, must, wine, vineyard, and cellars) to produce a novel ale beer. Fermentation activity of the strains was compared against the commercial strain Saccharomyces cerevisiae Safale S-04. In addition to the other aspects such as melatonin production, thirty-three volatile compounds belonging to higher alcohols, esters, aldehydes/cetones, acids, lactones and phenolic groups, were analysed by GC for selection of the strains. Ten strains were finally chosen, among which the most relevant was the strain G 520 showing a higher production of esters, higher alcohols and acids compared with S-04. The apparent attenuation for this strain was lower than commercial strain, which translates into more residual sugars. Furthermore, G 520 was more capable of producing significantly higher amounts of melatonin studied by HPLC, as well as showing a higher antioxidant capacity. Consumer study showed that G 520 strain could be used to produce a potential beer that has a place in the current market.

Alcohol consumption and overweight in Brazilian adults - CUME Project

This is a cross-sectional study with 2,909 participants (aged ≥18 years) from the baseline of the Cohort of Universities of Minas Gerais [CUME - Coorte de Universidades Mineiras] which verified the association between alcohol consumption and overweight. Data on sociodemographic factors, lifestyle, eating habits, anthropometric factors and clinical conditions were collected through an online questionnaire. Body mass index ≥ 25 kg/m² was considered an indicator of overweight. The daily consumption of alcohol was evaluated in grams (alcohol) and according to type in milliliters (beer, wine, hard liquor). The prevalence of alcohol consumption and overweight was 73.6% and 40.8%, respectively. There was a significant tendency of an increase in overweight with higher beer consumption (tendency p value of 0.038), which was not observed for the other types of alcohol. After sensitivity analyses, alcohol consumption was associated to overweight, with a tendency of increase in prevalence with higher daily consumption. There is a crucial need to curb the widely accepted idea that a low or moderate alcohol consumption is not harmful to one's health, and to be cautious of such a proposition. The influence of alcohol consumption regarding weight gain must be considered in public health policies and policies of alcohol consumption control.

A Simple Method for Evaluating the Bioactive Phenolic Compounds' Presence in Brazilian Craft Beers

There are a significant number of analytical methodologies employing different techniques to determine phenolic compounds in beverages. However, these methods employ long sample preparation processes and great time consumption. The aim of this paper was the development of a simple method for evaluating the phenolic compounds’ presence in Brazilian craft beers without a previous extraction step. Catechin, caffeic acid, epicatechin, p-coumaric acid, hydrated rutin, trans-ferulic acid, quercetin, kaempferol, and formononetin were analyzed in fifteen different craft beers. The method showed good linearity (R² ≥ 0.9966). The limit of detection ranged from 0.08 to 0.83 mg L⁻¹, and limits of quantification were between 0.27 and 2.78 mg L⁻¹. The method showed a satisfactory precision (RSD ≤ 16.2%). A good accuracy was obtained by the proposed method for all phenolic compounds in craft beer (68.6% ˂ accuracy ˂ 112%). Catechin showed higher concentrations (up to 124.8 mg L⁻¹) in the samples, followed by epicatechin (up to 51.1 mg L⁻¹) and caffeic acid (up to 8.13 mg L⁻¹). Rutin and formononetin were observed in all analyzed samples (0.52 mg L⁻¹ to 2.40 mg L⁻¹), and kaempferol was less present in the samples. The presence of plant origin products was determinant for the occurrence of the highest concentrations of phenolic compounds in Brazilian craft beers.

Bioaccessibility and Gut Metabolism of Free and Melanoidin-Bound Phenolic Compounds From Coffee and Bread

The aim of this study is to investigate the bioaccessibility and gut metabolism of free and melanoidin-bound phenolic compounds from coffee and bread. Phenolics from coffee were predominantly found in free forms (68%, mainly chlorogenic acids), whereas those from bread were mostly bound to melanoidins (61%, mainly ferulic acid). Bioacessibility of coffee total free phenolics slightly decreased during simulated digestion (87, 86, and 82% after the oral, gastric, and intestinal steps, respectively), with caffeoylquinic acids being isomerized and chlorogenic acids being partially hydrolyzed to the corresponding hydroxycinnamic acids. Bioacessibility of bread total free phenolics decreased during simulated digestion (91, 85, and 67% after the oral, gastric, and intestinal steps, respectively), probably related to complexation with the proteins in simulated gastric and intestinal fluids. Upon gut fermentation, the bioaccessibility of total free phenolics from both coffee and bread decreased, mainly after the first 4 h (56 and 50%, respectively). Caffeic and ferulic acids were the predominant metabolites found during coffee and bread gut fermentation, respectively. Melanoidin-bound phenolics from coffee and bread were progressively released after the gastric and intestinal steps, probably due to hydrolysis caused by the acidic conditions of the stomach and the action of pancreatin from the intestinal fluid. The bioaccessibilities of all phenolics from coffee and bread melanoidins after the gastric and intestinal steps were, on average, 11 and 26%, respectively. During gut fermentation, phenolics bound to both coffee and bread melanoidins were further released by the gut microbiota, whereas those from coffee were also metabolized. This difference could be related to the action of proteases on melanoproteins during gastrointestinal digestion, probably anticipating phenolics release. Nevertheless, bioaccessibilities of melanoidin-bound phenolics reached maximum values after gut fermentation for 24 h (50% for coffee and 51% for bread). In conclusion, the bioaccessibilities of coffee and bread free phenolics during simulated digestion and gut fermentation were remarkably similar, and so were the bioaccessibilities of coffee and bread melanoidin-bound phenolics.

Effects of adding spices with antioxidants compounds in red ale style craft beer: A simplex-centroid mixture design approach

The growing demand for authentic products that provide sensory characteristics combined with health benefits has been the focus of current studies. This study developed a Red Ale style craft beer with spices such as turmeric (T), black pepper (P) and aroma hops (H), used isolated or in mixtures. A mixture design was employed to evaluate the total phenolic compounds and the antioxidant activity in the green and aged beers formulations. The spice extracts influenced the product's shelf-life. The addition of spices into the beers did not affect the physicochemical parameters that classify the Red Ale style, according to the hierarchical cluster analysis, except for aroma hops. A multiresponse optimization approach simultaneously maximized the antioxidant activity and the phenolic compounds in beers. The ideal formulation obtained for green beers was 25% T and 37.5% P and H; for aged beers, the formulation was 50% T, 20% P and 30% H.

Characterization and Discrimination of Commercial Portuguese Beers Based on Phenolic Composition and Antioxidant Capacity

Beer has been highly appreciated due to its phenolic composition and antioxidant capacity conjugated with its low alcohol content. Although some studies exist regarding the phenolic composition and antioxidant capacities of beers, there are no studies related to the determination of these parameters in the most commonly consumed commercial beers in Portugal. The phenolic composition and antioxidant capacity of 23 Portuguese commercial beers of different styles and types were studied for the first time. The total phenolic content, ortho-diphenols, and flavonoids ranged between 0.15 ± 0.01 and 0.82 ± 0.07 g Gallic Acid (GA) L⁻¹; 0.07 ± 0.02 and 1.80 ± 0.09 g GA L⁻¹, and 0.02 ± 0.00 and 0.15 ± 0.02 g Catechin (CAT) L⁻¹, respectively. An accurate quantitative phenolic analysis was also performed, and the compound identified with a higher amount was gallic acid, followed by syringic acid. Concerning flavonoids, gallo-catechin was the most abundant compound identified (from 21.44 ± 2.87 and 144.00 ± 10.93 μg mL⁻¹). A significant correlation between ortho-diphenols and the antiradical capacity (ABTS and DPPH) was found, the latter being negatively correlated. Flavonoids content was also positively correlated with total phenols and antiradical capacity determined by the ABTS assay. These results evidence that phenolic composition is affected by several factors inherent to beers, namely ingredients, fermentation type, and brewing process.

Influence of fermentation temperature and yeast type on the chemical and sensory profile of handcrafted beers

BACKGROUND

Various physicochemical parameters, the polyphenolic content, the volatile fraction as well as the sensory profile of beers were studied using five different yeast strains (three top-fermentation and two bottom-fermentation) and two different fermentation temperatures (12 and 18 °C) for each of them.

RESULTS

The results indicated that at lower fermentation temperatures, the yeast strain factor was less significant for the various physicochemical parameters considered. The polyphenolic content increased as the fermentation temperature decreased, and significantly higher amounts of tyrosol were found in the samples fermented at 12 °C. However, the volatile content increased for beers fermented at 18 °C, these beers being better evaluated from the sensory point of view.

CONCLUSIONS

No clear relationship was observed between the temperature used and the type of yeast, with more complex aroma and sensory profiles being found in beers fermented at higher temperatures, using yeasts that are supposedly suitable for use at lower temperatures. © 2020 Society of Chemical Industry.

The Role of Bioactive Phenolic Compounds on the Impact of Beer on Health

This review reports recent knowledge on the role of ingredients (barley, hop and yeasts), including genetic factors, on the final yield of phenolic compounds in beer, and how these molecules generally affect resulting beer attributes, focusing mainly on new attempts at the enrichment of beer phenols, with fruits or cereals other than barley. An entire section is dedicated to health-related effects, analyzing the degree up to which studies, investigating phenols-related health effects of beer, have appropriately considered the contribution of alcohol (pure or spirits) intake. For such purpose, we searched Scopus.com for any kind of experimental model (in vitro, animal, human observational or intervention) using beer and considering phenols. Overall, data reported so far support the existence of the somehow additive or synergistic effects of phenols and ethanol present in beer. However, findings are inconclusive and thus deserve further animal and human studies.

Wine or Beer? Comparison, Changes and Improvement of Polyphenolic Compounds during Technological Phases

Wine and beer are nowadays the most popular alcoholic beverages, and the benefits of their moderate consumption have been extensively supported by the scientific community. The main source of wine and beer's antioxidant behavior are the phenolic substances. Phenolic compounds in wine and beer also influence final product quality, in terms of color, flavor, fragrance, stability, and clarity. Change in the quantity and quality of phenolic compounds in wine and beer depends on many parameters, beginning with the used raw material, its place of origin, environmental growing conditions, and on all the applied technological processes and the storage of the final product. This review represents current knowledge of phenolic compounds, comparing qualitative and quantitative profiles in wine and beer, changes of these compounds through all phases of wine and beer production are discussed, as well as the possibilities for increasing their content. Analytical methods and their importance for phenolic compound determination have also been pointed out. The observed data showed wine as the beverage with a more potent biological activity, due to a higher content of phenolic compounds. However, both of them contain, partly similar and different, phenolic compounds, and recommendations have to consider the drinking pattern, consumed quantity, and individual preferences. Furthermore, novel technologies have been developing rapidly in order to improve the polyphenolic content and antioxidant activity of these two beverages, particularly in the brewing industry.

Influence of malt composition on the quality of a top fermented beer

The beer is a widely consumed drink, appreciated for its sensory characteristics, and it also contains beneficial compounds for health derived from its raw materials. In this work, the influence of coloured malt on the main quality parameters of a top-fermenting beer was evaluated. The beers were produced increasing the percentage of coloured malt (0, 5, 15% Caraamber®) respect to the pale ale base malt. The beers had an alcohol content ranging from 6.2 to 6.8 vol%; the results highlighted a deeper colour, increased bitterness and turbidity in beer with the highest amount of Caraamber malt. This latter showed the highest polyphenols (453.8 mg GAE/L) and antioxidant activity (840.1 µmol TE/L) and, on the other hand, the lowest foam stability. The volatiles profile showed a higher amount of aldehydes and ketones in beer with the highest percentage of caramel malt but the lowest in higher alcohols and esters. No differences were found in the fruity-esters, alcoholic and caramel sensory notes; while the beer made with 15% of coloured malt was perceived sweeter and with less fruity citrus notes than other beer samples.

The Mineral Profile of Polish Beers by Fast Sequential Multielement HR CS FAAS Analysis and Its Correlation with Total Phenolic Content and Antioxidant Activity by Chemometric Methods

Beer is the most common alcoholic beverage worldwide, and is an excellent source of macro- and microelements, as well as phenolic compounds. In this study, a fast method for the determination of Na, K, Mg, Ca, Fe, Mn, and Cu in beer was developed using flame atomic absorption spectrometry. The precision of this method was between 0.8 and 8.0% (as the relative standard deviation (RSD)), and limits of detections were in the range of 0.45 (Mn)–94 µg/L (Na). Among the macroelements tested in the beer samples, K was found at the highest concentration, whereas Na was found at the lowest concentration level. Beer also turned out to be a good source of Mg and K. The total phenolic content (TPC) was determined by the Folin–Ciocalteu method, while the antioxidant activity was estimated by the ABTS method. The results show remarkable variations in the mineral content, TPC, and antioxidant activity across the beer types and brands. Moreover, the relations between the type, color, refraction index, antioxidant activity, extract, alcohol, mineral, and the total phenolic contents were investigated using the factor analysis of mixed data (FAMD) combined with hierarchical clustering on principal components (HCPC).

Analysis of chemical compounds in beverages - Guidance for establishing a compositional analysis

In recent years, much analysis has been carried out regarding the chemical compositions of nonalcoholic and alcoholic beverages. However, no study has ever considered the compositional pitfalls inherent in such studies, which may lead to arbitrary results. Two approaches were compared in this paper, compositional data analysis (CoDa) and classical statistical analyses, to demonstrate (1) how aging affects beer and (2) how the results vary depending on the applied approach. Exemplarily, chemical compounds of 43 beer samples were analyzed. Our work has led us to obtain different results when the correlation analysis and principal component analysis were conducted on the unmodified-, log-transformed-, or closed-data in contrary to the analyses of log-ratio coordinates. The outcome of the latter provided better separation between aged and fresh beer samples and also easier interpretability. These results lead us to advise the usage of CoDa methods for the analyses of chemical compositions of beverages.

Phenols and Melanoidins as Natural Antioxidants in Beer. Structure, Reactivity and Antioxidant Activity

Beer is one of the most consumed drinks around the world, containing a variety of compounds that offer both appreciated sensorial characteristics and health advantages. Important healthy compounds in beer are those with antioxidant properties that attenuate the content of free radicals produced as by-products in the human metabolism, exerting an appreciable effect against cancers or cardiovascular diseases. This work details a study of antioxidant compounds present in beer, focusing on the two main groups: phenols (including polyphenolic forms) and melanoidins, formed specifically during brewing as Maillard products. The fundaments of the most important methods to evaluate beer antioxidant activity, the main antioxidant compounds present in beer-especially those with healthy properties-and the new trends to increase beer antioxidant activity are also discussed.

Characteristics of Cornelian cherry sour non-alcoholic beers brewed with the special yeast Saccharomycodes ludwigii

Recipes for traditional and sour non-alcoholic beers were developed in this study employing a special yeast species Saccharomycodes ludwigii. They were characterized for their basic physicochemical properties, antioxidative activity as well as subjected to the quantitative and qualitative analysis of their biologically-active compounds, and to the sensory assessment. Sour non-alcoholic beers were brewed with the addition of juice from fruits of red-colored Cornelian cherry (Cornus mas L.) variety, which are characterized by naturally sour taste and aroma. Ethyl alcohol content in the beers manufactured ranged from 0.41%v/v in traditional non-alcoholic beers to 0.43%v/v in sour non-alcoholic beers. The final products had a low energy value, ranging from 116 to 148 kcal/500 mL of beer. The sour beers had several times higher antioxidative potential and significantly higher polyphenols concentration compared to the control ones. In addition, they were rich in anthocyanins and iridoids, and presented novel sensory attributes.

Technological influence on sensory stability and antioxidant activity of beers measured by ORAC and FRAP

BACKGROUND

Many studies have confirmed a wide variation in the phenolic content and antioxidant activity of beers. However, when commercial beers are studied, there is usually no information available on the brewing technology applied. In this study, technological parameters were varied systematically to influence the antioxidant content of beer with a view to improving its flavor stability. High-throughput assays, ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) were investigated as fast analytical methods to evaluate the influence of brewing technology on antioxidant activity.

RESULTS

Beers (n = 12) were brewed with systematic technological variations (malt modification, hopping regime) to influence the antioxidant potential. A late hop addition resulted in significantly higher phenolic content (high-performance liquid chromatography with diode-array detection - HPLC-DAD) and antioxidant activity. Raw protein content and malt modification significantly influenced phenolic content and the antioxidant activity of beers hopped at the beginning of wort boiling. Samples were stored under forced and natural conditions and were evaluated by a sensory panel. The decline of bitter iso-α-acids as an analytical marker for oxidative aging was significantly lower in beers brewed from malts with high raw protein content. These samples also had higher antioxidant activity values. Panelists gave higher ratings for beer quality to aged beers with a late hop addition. However, late hopping resulted in enhanced hoppy aroma attributes and therefore an altered aroma profile.

CONCLUSIONS

Both antioxidant capacity methods were well suited as fast methods to evaluate brewing raw material and technological influence on antioxidant activity. The appropriate choice of barley malt and the malting regime could be promising tools to enhance the antioxidant activity of traditionally hopped beers. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Beer consumption negatively regulates hormonal reproductive status and reduces apoptosis in Leydig cells in peripubertal rats

Beer is one of the most popular alcoholic beverages consumed by young people. Ethanol intake is associated with harmful effects to the reproductive system. Bioactive compounds present in beer may diminish the toxics effect of ethanol. However, there is still little knowledge about the effect of beer consumption on hormonal regulation of male reproduction in organisms exposed to alcohol after the peripubertal age. Therefore, the aim of this study was to determine the influence of beer intake on plasma reproductive hormones, immunolocalization of cleaved caspase-3 (casp-3), and the level of the neuronal isoform of nitric oxide synthase (nNOS) in Leydig cells (LCs) in adolescent male Wistar rats. The animals, beginning at the age of 30 days, drank beer (10% ethanol; B2 group [2 weeks' exposure] and B4 group [4 weeks' exposure]), 10% ethanol solution (CE2 group [2 weeks' exposure] and CE4 group [4 weeks' exposure]), or water (C2 group [2 weeks' exposure] and C4 group [4 weeks' exposure]). Rats drinking beer for 4 weeks showed higher phenolic acid intake compared to rats drinking beer for 2 weeks. Rats exposed to beer for 4 weeks showed decreased plasma levels of follicle-stimulating hormone (FSH) and 17β-estradiol (E2) (3.173 ng/mL and 11.49 pg/mL, respectively), compared to the CE4 (5.293 ng/mL and 43.912 pg/mL, respectively) and the C4 groups (5.002 ng/mL and 41.121 pg mL, respectively). Expression of cleaved caspase-3 in LCs was lower in the B4 group rats, compared to the CE4 group rats (ID score: 1.676 vs. 2.190). No changes in nNOS expression were observed. Beer consumption revealed a similar negative effect on hormonal regulation of male reproductive function, but lower apoptosis in LCs may be beneficial for steroidogenic activity.

Beer Molecules and Its Sensory and Biological Properties: A Review

The production and consumption of beer plays a significant role in the social, political, and economic activities of many societies. During brewing fermentation step, many volatile and phenolic compounds are produced. They bring several organoleptic characteristics to beer and also provide an identity for regional producers. In this review, the beer compounds synthesis, and their role in the chemical and sensory properties of craft beers, and potential health benefits are described. This review also describes the importance of fermentation for the brewing process, since alcohol and many volatile esters are produced and metabolized in this step, thus requiring strict control. Phenolic compounds are also present in beer and are important for human health since it was proved that many of them have antitumor and antioxidant activities, which provides valuable data for moderate dietary beer inclusion studies.

Sensory Profile, Consumer Preference and Chemical Composition of Craft Beers from Brazil

Craft beers are known for their distinct flavor, brew, and regional distribution. They are made using top-fermenting (ale) yeast, bottom-fermenting (lager) yeast, or through spontaneous fermentation. Craft beers are consumed and produced in Brazil in large quantities. However, they present a high level of polyphenols, which affects consumer preference as they may yield a taste of bitterness to beers. In this study, we analyzed the relationship between polyphenols and bitterness as well as the composition of the main styles of craft beers and consumer preference for them. Six different styles were analyzed according to their polyphenol content, bitterness, chemical composition, sensory profile, and preference. For preference, a panel of 62 untrained assessors was used. For sensory profile, quantitative descriptive analysis was performed using expert assessors (n = 8). The most preferred style was classic American pilsner, and the least preferred was standard American lager. The most preferred style showed less bitterness (9.52) and lower polyphenol content (0.61 mg EAG/mL), total solids (6.75 °Brix), and turbidity (7.27 NTU). This beer also exhibited reduced sensory notes of malty, fruity, smoked, hoppy, and phenolic but a higher perception of floral, sweet, and yeast notes; the bitterness attribute had a reduced perception. This study advances the understanding and complexity of the sensory profile of different styles of craft beers from Southern Brazil.

Phenolic Substances in Beer: Structural Diversity, Reactive Potential and Relevance for Brewing Process and Beer Quality

For the past 100 years, polyphenol research has played a central role in brewing science. The class of phenolic substances comprises simple compounds built of 1 phenolic group as well as monomeric and oligomeric flavonoid compounds. As potential anti- or prooxidants, flavor precursors, flavoring agents and as interaction partners with other beer constituents, they influence important beer quality characteristics: flavor, color, colloidal, and flavor stability. The reactive potential of polyphenols is defined by their basic chemical structure, hydroxylation and substitution patterns and degree of polymerization. The quantitative and qualitative profile of phenolic substances in beer is determined by raw material choice. During the malting and brewing process, phenolic compounds undergo changes as they are extracted or enzymatically released, are subjected to heat-induced chemical reactions or are precipitated with or adsorbed to hot and cold trub, yeast cells and stabilization agents. This review presents the current state of knowledge of the composition of phenolic compounds in beer and brewing raw materials with a special focus on their fate from raw materials throughout the malting and brewing process to the final beer. Due to high-performance analytical techniques, new insights have been gained on the structure and function of phenolic substance groups, which have hitherto received little attention. This paper presents important information and current studies on the potential of phenolics to interact with other beer constituents and thus influence quality parameters. The structural features which determine the reactive potential of phenolic substances are discussed.

Decomposição de amostras de cerveja com sistema de refluxo para determinação monoelementar por F AAS/AES e determinação multielementar por MIP OES

Resumo Neste trabalho, é descrito o desenvolvimento de um método analítico para análise de amostras de cervejas por técnicas de espectrometria. As amostras foram preparadas por decomposição em meio ácido, em um sistema de refluxo, e as determinações foram realizadas por F AAS (Fe, Mg e Zn), F AES (Na) e MIP OES (Ca, Fe, K, Mg, Mn, Na, Ni e Zn). As melhores condições para a decomposição da amostra foram obtidas através de estudo com delineamento composto central rotacional: volume de 10,0 mL de cerveja desgaseificada, adição de 5,0 mL de HNO3 e 2,0 mL H2O2, seguida por uma etapa de aquecimento em bloco digestor a 160 °C, por 93 min. Os limites de quantificação do método foram ≤ 0,100 mg L-1 para todos os elementos investigados, independentemente da técnica analítica utilizada, ficando abaixo, por exemplo, dos valores estipulados para Zn e Ni, pela Agência Nacional de Vigilância Sanitária do Brasil. Os estudos comparativos entre as diferentes técnicas avaliadas mostraram, pelo teste T com nível de 90% de confiança, que não há diferença significativa para as determinações de Fe, Mg, Na e Zn nas amostras de cerveja. O método de preparo da amostra proposto mostrou ser simples, rápido, de baixo custo e confiável, para análise de cervejas nas diferentes técnicas de espectrometria atômica.