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

Unconventional raw materials used in beer and beer-like beverages production: Impact on metabolomics and sensory profile

Beer is the third most consumed beverage in the world, trailing only water and tea but ranking first among alcoholic beverages. In recent years, producers and researchers have shown a growing interest in brewing diversification and innovation, due to of the widespread consumption of beer. In order to create beers and beer-like products with unique and consumer-pleasing characteristics, the use of unconventional raw materials has become a subject of intensive research. The purpose of this paper is to identify, evaluate and summarize the findings of all relevant unconventional raw materials used in relevant scientific studies, as well as the effect on the metabolomics of beer and beer-like beverages.For the enhancement of beer characteristics, the production process may involve the use of an extremely diverse variety of unconventional raw materials that are not included on thelist of usual ingredients for the beer industry. However, the general trend is to use locally available ingredients as well as functional ingredients. Twoof the most studied functional characteristics involve phenolic compounds and antioxidant activity, which is why the fruit is by far the most commonly used adjunct category, as fruits are particularly important sources of polyphenols and antioxidants. Other uncommon adjuncts used in brewing includeplants, starch sources, spices or even propolis. Moreover, unconventional raw materials are used to enhance the sensory profile by create new characteristics such as new tastes and flavors, accentuation of the cooling sensation or even increasing acceptability among potential consumers, who do not appreciate traditional beers due to their specific characteristics.

An Overview on Flavor Extraction, Antimicrobial and Antioxidant Significance, and Production of Herbal Wines

Wine has been utilized as a source for medicinal preparations, combined with various herbs, to treat particular ailments and disorders. By utilizing herb extracts, regular but limited consumption of these herbal wines helps to decrease the need for prescription medications to treat a variety of ailments. The diversity and the composition of the yeast micropopulation significantly contribute to the sensory characteristics of wine. A particular metabolic activity characterizes the growth of each wine yeast species, which determines the concentrations of flavor compounds in the final wine. Numerous herbs, such as tulsi, ginger, aloe vera, tea, amla, lemongrass, and peppermint, are used in the preparation of herbal wines, where either the herb or herbal blends are primarily used as the substrate. The variants provided improved accuracy, increased acceptability, and broader uses for the novel product. Herbal wines pave the way to provide nutraceuticals to consumers and protection against pathogenic microorganisms and inflammation through their richness in antioxidants. The existing herbal wines and their health advantages are discussed in this Review, along with some new directions for the herbal wine business.

Effect of mashing temperature on fermentation and antioxidant capacity of Qingke wort

Background and Objectives

Mashing temperature is important during beer brewing processes. Qingke malt was a new material whose application in the beer industry holds significant importance for the beer industry and agriculture development in the Qinghai–Tibet Plateau. The objective of this study was to investigate the effects of mashing temperature on the physicochemical parameters, fermentation capacity, and antioxidant capacity of Qingke wort.

Findings

Ethanol production and the real degree of fermentation decreased with increasing the temperature—S, while the real extract increased with increasing the temperature—S. A lower temperature—S proved to be more advantageous for the fermentation capacity of Qingke wort. In addition, a positive correlation between reducing power and the temperature—P and a negative correlation between the 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate) free radical scavenging activity and the temperature—S were found.

Conclusion

The fermentation capacity of Qingke wort was obtained the best when the temperature—P was 50°C and the temperature—S was 60°C. The antioxidant capacity of Qingke wort was satisfactory; the best was obtained when the temperature—P was 45°C and the temperature—S was 60°C.

Significance and Novelty

This is the first study to investigate the mashing characteristics of Qingke wort under different mashing temperatures. The results show that β‐glucan content was abundant in Qingke wort and was positively correlative with the temperature—S.

Addition of Spirulina to Craft Beer: Evaluation of the Effects on Volatile Flavor Profile and Cytoprotective Properties

SPME-GC-MS and PTR-ToF-MS techniques were applied to describe the content of volatile flavor compounds in a craft beer before and after adding spirulina. The obtained results showed that the volatile profile of the two beer samples differed. Furthermore, to chemically characterize biomass spirulina, a derivatization reaction followed by GC-MS analysis was performed, highlighting a high content of molecules belonging to different chemical classes, such as sugars, fatty acids and carboxylic acids. A spectrophotometric analysis of total polyphenols and tannins, investigation into the scavenging activity towards DPPH and ABTS radicals and confocal microscopy of brewer's yeast cells were carried out. Moreover, the cytoprotective and antioxidant properties towards the oxidative damage induced by tert-butyl hydroperoxide (tBOOH) in human H69 cholangiocytes were investigated. Finally, the modulation of Nrf2 signaling under oxidative stress conditions was also evaluated. Both samples of beer were shown to contain similar levels of total polyphenols and tannins, with slightly increased levels in that containing spirulina 0.25% w/v. Moreover, the beers were found to be endowed with radical scavenging properties towards both DPPH and ABTS radicals, albeit with a weak contribution of spirulina; however, a higher riboflavin content was detected in spirulina-treated yeast cells. Conversely, the addition of spirulina (0.25% w/v) appeared to improve the cytoprotective properties of beer towards tBOOH-induced oxidative damage in H69 cells and reduce intracellular oxidative stress. Accordingly, the cytosolic Nrf2 expression was found to be increased.

The Risk of Breast Cancer between Western and Mediterranean Dietary Patterns

Breast cancer is a significant public health problem globally and prevention strategies have become of great interest as its incidence rises. Exploring the connection between dietary patterns and the reduction of breast cancer risk is considered a promising approach. High levels of fiber, phytochemicals, a good antioxidant profile, and a composition of advantageous fatty acids are characteristics of healthy dietary programs such as the Mediterranean diet. This review summarized and discussed the active compounds that are considered important in preventing breast cancer, including dietary components from recent related reports. These include polyunsaturated fatty acids, fiber, phytochemicals, and alcohol. Although the exact mechanism for preventing breast cancer using these dietary factors is not well understood, the combination of all the elements in a healthy diet plays a role in reducing breast cancer risk. Considering the elevated probability of breast cancer relapse and mortality, it is crucial to investigate the correlation between a nutritious dietary pattern and breast cancer, while identifying bioactive components that have the potential to mitigate the risk of breast cancer incidence.

Bioactive Properties and Phenolic Composition of Wood-Aged Beers: Influence of Oak Origin and the Use of Pale and Dark Malts

Ageing beer in contact with wood is a common technological procedure that has been used for centuries to improve colour, structure, and certain flavours. Herein, the impact of the addition of French and American oak wood to two beer styles, pale and dark, on beer phenolic composition (total phenolics, total flavonoids, and HPLC-DAD) and bioactivity (FRAP, DPPH, anti-inflammatory activity in RAW 264.7, and antiproliferative in Caco-2 cells) was assessed. Thirteen phenolics were quantified with values according to previous reports. Dark malt resulted in higher values of total phenolics, to which m-hydroxybenzoic, syringic, p-coumaric acids, and xanthohumol contributed considerably; the exception was (+)-catechin and salicylic acid, which were found to be higher in pale beers. American oak significantly increased 3,4-dihydroxyphenylacetic, vanillic, and syringic acids up to roughly 3, 2, and 10 times, respectively, when compared with French wood. FRAP and DPPH values varied between pale and dark beers, with a less pronounced effect after wood addition. All samples presented considerable cellular antioxidant and anti-inflammatory as well as antiproliferative activity, but differences were found only for the antiproliferative activity, which was higher for the dark beers, which reached about 70% inhibition. Overall, the influence of malts was more pronounced than that of wood, in the studied conditions, highlighting the overwhelming impact of malts on the bioactivity of beer.

Identification and Analysis of Metabolites That Contribute to the Formation of Distinctive Flavour Components of Laoxianghuang

In addition to volatile compounds, metabolites also have a great effect on the flavour of food. Fresh finger citron cannot be eaten directly because of its spicy and bitter taste, so it is made into a preserved fruit product known as Laoxianghuang (LXH). To investigate the metabolites that have an effect on the flavour of LXH, untargeted metabolomics was performed using an ultrahigh-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS), and the metabolites of the Laoxianghuang samples from different locations in the Chaoshan area were compared and analysed. A total of 756 metabolites were identified and distinct differences were revealed among the different Laoxianghuang samples. A total of 33 differential metabolites with the most significant changes were screened through further multivariate analytical steps, and each group of samples had unique metabolites. For instance, pomolic acid had the highest content in the JG sample, while L-glycyl-L-isoleucine was rich in the QS sample. Moreover, flavonoid metabolites made the greatest contribution to the unique flavour of Laoxianghuang. The metabolic pathways involved are the biosynthetic pathways of flavonoids, isoflavonoids, flavones, and flavonols. This study can provide some creative information for distinguishing the quality differences of Laoxianghuang from the perspective of metabolites and offer preliminary theoretical support to characterise the formation of flavour substances in Laoxianghuang.

Sour Beer with Lacticaseibacillus paracasei subsp. paracasei F19: Feasibility and Influence of Supplementation with Spondias mombin L. Juice and/or By-Product

This study aimed to evaluate the probiotic strain Lacticaseibacillus (L.) paracasei subsp. paracasei F19 (F19) with the yeast Saccharomyces cerevisiae US-05 (US-05), using Spondias mombin L. ('taperebá' or 'cajá') juice and by-product, in four sour-type beer formulations: control, with bagasse, juice, and juice and bagasse. The viability of F19 was evaluated by pour-plating and PMA-qPCR. Fermentability, in addition to physicochemical and sensory parameters, and aroma and flavor, were evaluated during brewery by using Headspace Solid-Phase Microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). F19 was successful in fermenting bagasse in a MRS medium (9.28 log CFU/mL in 24 h) but had a low viability in hopped wort, growing better in formulations without bagasse or juice. No difference between formulations was observed regarding sensory acceptability, and the HS-SPME/GC-MS revealed different flavors and aroma compounds. In conclusion, the production of a potential probiotic sour beer with F19 and US-05 is feasible regarding probiotic viability. However, S. mombin, as juice or bagasse, threatened probiotic survival. Different flavors and aroma compounds were detected, whereas no difference between formulations was found regarding sensory acceptability. The moderate alcohol content achieved is important for bacterial survival and for the development of a probiotic beer with health claims.

Analytical determination of antioxidant capacity of hop-derived compounds in beer using specific rapid assays (ORAC, FRAP) and ESR-spectroscopy

There is a relationship between antioxidant activity and ageing stability of beer. The high-throughput antioxidant capacity assays ORAC and FRAP, which rely on specific reaction mechanisms, are validated as an addition to the established ESR-ST method with a focus on hop-derived antioxidants. Beers were brewed with systematic variations in hop variety, hop product, and the hopping regime (late hopping) to achieve sample beers varying widely in the concentrations of hop-derived antioxidants (α- and iso-α-acids, phenolic compounds). A significant positive correlation between phenolic compounds and the ORAC- and FRAP-values (p < 0.01) was found. The effect of individual resinous substances and free phenolic acids and flavonoids on the antioxidant capacity of beer (ORAC, FRAP, and ESR-ST) was proven in spiking trials. We found a correlation between the occurrence of the o-di-OH-group and the ORAC- and FRAP-values of phenolic compounds. Phenolic compounds did not react as anti- or prooxidants in the radical generation (ESR-ST). Higher concentrations of unisomerized α-acids significantly reduced ESR-signal intensity but had no significant effect on ORAC- or FRAP-values. Beers brewed with late hop addition, which yielded higher concentrations of unisomerized α-acids and phenolic compounds, had higher ORAC, FRAP-values and a reduced ESR-signal intensity. These three methods rely on different reaction principles, and therefore, different groups of hop-derived compounds act as antioxidants in these assays. A combination of the two high-throughput methods (ORAC, FRAP) and ESR-ST is advantageous for the evaluation of the antioxidant capacity of beers varying in hop-derived compounds.

Developing colloidal structure of beer by grain organic compounds

The present article introduces the problem of determining the general structure of beer as a complex system of related biomolecules. The objective was to establish the correlation of various quantities of organic compounds in beer formulation. The research featured samples of filtered pasteurized beer obtained from a retail chain shop in Moscow (Russia). The experiment relied on standard research methods, including instrumental methods of analysis, e.g., high-performance liquid chromatography (HPLC). The obtained experimental data underwent a statistical analysis using the Statistica software (StatSoft, 2016). The research established the correlation between the type of grain (barley or wheat malt) and the content of organic compounds, e.g., β-glucan, polyphenols, soluble nitrogen, etc. The research also revealed some patterns in the distribution of proteins, which served as a framework for the system of organic compounds. The distribution of thiol proteins proved to depend on the dissolution degree of the grain and was different in barley light, barley dark, and wheat malt samples. The fraction distribution of β-glucan depended on the color of the malt. In light beer samples, it concentrated in high- and medium-molecular fractions of nitrogenous substances, in dark beer – in low-molecular fractions (≤ 63%). Initial wort density and alcohol content affected the amount of catechins and total polyphenols. Nitrogenous compounds depended on the color, initial extract, and alcohol content. The nitrogenous structure and other organic compounds of beer proved to depend on protein substances. The research also revealed a number of factors that affected the fraction distribution of biomolecules in different beer sorts.

The effect of malting on phenolic compounds and radical scavenging activity in grains and breakfast cereals

Breakfast cereals are popular grain foods and sources of polyphenols. Malting alters polyphenol content and activity; however, effects are varied. The total polyphenol content (TPC), radical scavenging activity (RSA), and polyphenol profile were analyzed in unmalted and malted grains (wheat, barley, and sorghum) and breakfast cereals (wheat, barley) by Folin Ciocalteu Reagent (FCR), % inhibition of the free radical 2,2-diphenyl-1-picryl-hydrazyl, and high performance liquid chromatography. Higher TPC was observed in all malted grains and breakfast cereals compared with unmalted samples (p < 0.05). Higher RSA was also observed in all malted samples compared to unmalted samples (p < 0.05) except for wheat grain to malted wheat grain. In this study, malting induced additional polyphenols and antioxidant activity in grains and cereal products. Malted grain breakfast cereals may be practical sources of polyphenol antioxidants. PRACTICAL APPLICATION: This study utilized malting in a unique way to investigate potential health benefits of polyphenols and antioxidant activity in grains (wheat, barley, and sorghum) and ready-to-eat breakfast cereals (wheat and barley). This study found that grains and breakfast cereals are important sources of antioxidant polyphenols, and these were significantly increased in malted varieties. Understanding this is important as grains and breakfast cereals are widely consumed staple foods. Consuming healthier grain products may be a practical strategy in reducing the risk of noncommunicable diseases such as colorectal cancer and type-2 diabetes, where wholegrain consumption may be important in prevention.

Characteristics of New England India Pale Ale Beer Produced with the Use of Norwegian KVEIK Yeast

The aim of this research was to determine the potential of four unconventional Norwegian yeasts of the KVEIK type to produce NEIPA beer. The influence of yeast strains on fermentation process, physicochemical properties, antioxidant potential, volatile compounds, and sensory properties was investigated. The KVEIK-fermented beer did not differ in terms of physicochemical parameters from the beer produced with the commercial variants of US-05 yeast. The yeast strain influenced the sensory quality (taste and aroma) of the beers, with KVEIK-fermented beer rating significantly higher. The antioxidant activity of the tested beers also significantly depended on the yeast strain applied. The beers fermented with KVEIK had a significantly higher antioxidant potential (ABTS^•+) than those fermented with US-05. The strongest antioxidant activity was found in the beer brewed with the Lida KVEIK yeast. The use of KVEIK to produce NEIPA beer allowed enrichment of the finished products with volatile compounds isobutanol, 2-pentanol, 3-methylobutanol, ethyl octanoate, and ethyl decanoate.

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.

Alcohol Consumption, Bone Mineral Density, and Risk of Osteoporotic Fractures: A Dose-Response Meta-Analysis

Excess alcohol consumption is known to be detrimental to human health. However, the role of light-to-moderate alcohol intake is under investigation for potential certain health benefits-mostly related to the cardiovascular system. Nevertheless, there is no univocal agreement on this matter, and research is still ongoing to clarify whether there might be other potential outcomes affected by alcohol intake. In this regard, there is evidence that excess alcohol intake may negatively influence the risk of osteoporotic fractures. However, there is no comprehensive evidence of literature assessing the role of alcohol consumption in bone mineral density (BMD) and the risk of osteoporotic fractures. Thus, the aim of this study was to quantitatively assess the dose-response relationship between alcohol intake and BMD and risk of osteoporotic fractures. The Embase and MEDLINE electronic databases were searched from their inception to December 2021 for articles providing a quantifiable measurement of alcohol consumption for at least three categories and (1) a measurement of BMD (and dispersion as continuous variables) in some area of the body or (2) risk of osteoporotic fracture provided as relative risk (RR) or hazard ratio (HR), with a 95% confidence interval (CI) as the measure of the association of each category with alcohol intake. A total of 11 studies including 46,916 individuals with BMD assessment and 8 studies including 240,871 individuals with risk of fracture analysis were included. Compared to non-drinkers, consumption of up to two standard drinks of alcohol per day was correlated with higher lumbar and femur neck BMD values, while up to one standard drink of alcohol was correlated with higher hip BMD compared to no alcohol consumption. Higher risk of hip fractures was found starting from three standard drinks of alcohol per day (RR = 1.33, 95% CI: 1.04; 1.69 for three alcoholic drinks/d, and RR = 1.59, 95% CI: 1.23; 2.05 for four alcoholic drinks/d) compared to no alcohol consumption, with no evidence of heterogeneity. Concerning the risk of any osteoporotic fractures, the risk steadily increased with higher intake of alcohol, although never reaching statistical significance. In conclusion, there is consistent evidence that increased alcohol consumption is associated with higher risk of osteoporotic hip fracture; however, the role of alcohol at lower doses is uncertain, as BMD was even higher in light drinkers compared to abstainers.

The Influence of Hop Phenolic Compounds on Dry Hopping Beer Quality

Background: The article considers the phenolic hop compounds’ effect on the quality indicators of finished beer. The topic under consideration is relevant since it touches on the beer matrix colloidal stability when compounds with potential destabilizing activity are introduced into it from the outside. Methods: The industrial beer samples’ quality was 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 made it possible to make assumptions about the functional dependence of the iso-α-bitter resins and isoxanthohumol content in beer samples. Mathematical analysis indicate interactions between protein molecules and different malted grain and hop compounds are involved in beer structure, in contrast to dry hopped beer, where iso-a-bitter resins, protein, and coloring compounds were significant, with a lower coefficient of determination. The main role of rutin in the descriptor hop bitterness has been established in kettle beer hopping technology, and catechin in dry beer hopping technology, respectively. The important role of soluble nitrogen and β-glucan dextrins in the perception of sensory descriptors of various technologies’ beers, as well as phenolic compounds in relation to the formation of bitterness and astringency of beer of classical technology and cold hopping, has been shown. Conclusions: The obtained mathematical relationships allow predicting the resulting beer quality and also make it possible to create the desired flavor profiles.

Biopreservation of beer: Potential and constraints

The biopreservation of beer, using only antimicrobial agents of natural origin to ensure microbiological stability, is of great scientific and commercial interest. This review article highlights progress in the biological preservation of beer. It describes the antimicrobial properties of beer components and microbiological spoilage risks. It discusses novel biological methods for enhancing beer stability, using natural antimicrobials from microorganisms, plants, and animals to preserve beer, including legal restrictions. The future of beer preservation will involve the skilled knowledge-based exploitation of naturally occurring components in beer, supplementation with generally regarded as safe antimicrobial additives, and mild physical treatments.

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.

Characterization of the Volatile Compounds of Zhenba Bacon at Different Process Stages Using GC-MS and GC-IMS

Zhenba bacon (ZB), a type of Chinese traditional bacon with a long history, has attracted considerable attention in the Southwest of China for its unique flavor. To elucidate the changing course of aroma components during the process of ZB, four stages of process stages were assessed by GC-MS and GC-IMS coupled with multivariate data analysis. A total of 44 volatile compounds were identified by GC-IMS, including 5 esters, 8 alcohols, 12 aldehydes, 3 ketones, 1 furan and 2 sulfides; 40 volatile compounds were identified by GC-MS, 4 ketones, 7 phenols, 8 alcohols, 6 esters, 6 aldehydes, and 6 other compounds were detected. During the curing period, the amount and content of esters in Zhenba bacon gradually increased. Phenols appear in large quantities during the smoking period. The VOCs (volatile organic compounds) in the gallery plots were the most diverse in YZ samples, which are mainly esters. POV (peroxide value) and TBARS (thiobarbituric acid reactive substance) showed that lipid oxidation played an important role in the formation of volatile flavor components of bacon. This study provides valuable analytical data to explain the flavor formation of Zhenba bacon.

Aroma and color development during the production of specialty malts: A review

Specialty malts comprise a promising field for innovative approaches concerning their potential in terms of color, aroma, and taste influence on the composition of beer and other beverages. Nevertheless, poor reproducibility of aroma and taste is a recurrent struggle between maltsters, leaving color as a practical parameter for quality control. However, malts with similar coloration can present distinct aroma profiles, leaving open questions concerning key aroma compounds, their dynamic responses to malting process variations and to what extent they may vary in a certain color range. Key aroma volatiles have been identified in the matrix of barley malt, comprising a variety of products of non-enzymatic browning reactions (e.g., caramelization, pyrolysis, and Maillard reactions). Here, water plays a crucial role together with the intensity of the temperature regimes. Nevertheless, the final aroma profile of a malt product is the result of a balance between aroma formation and losses. Therefore, the correlation between color and aroma is of big complexity. That being the case, the present article questions if key aroma compounds responsible for the peculiar flavors of specialties have been defined by scientific literature and whether their production dynamics is unveiled. In this manner, this work proposes an overview of the aroma compounds present in specialty malt products studied up to the current date. More specifically, the process production of specialty malts and its potential impact on the formation of aroma and taste is studied alongside the key aroma-active compounds, their correlation to color, and trending analytical techniques for aroma and color assessment.

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.

Effect of grinding and extraction conditions on the determination of antioxidant activity and phenolic acids in barley

In the present study, the objective was to evaluate the effects of barley kernel size, grind level, and extract solvent on the antioxidant activities associated with total phenolic content and phenolic acid compositions. Three barley varieties (Kindred, Azure, and Tradition), were used and the results showed that with the exception of superoxide anion radical scavenging activity, thin kernel size fraction (2.0 mm) showed much higher antioxidant activities and total phenolic content than those in the 2.4 mm and 2.8 mm fractions when averaged across barley cultivar, grind level, and extract solvent. A similar trend was found for individual phenolic acid compositions among kernel sizes. Simple correlation analysis revealed that total phenolic content showed strong correlation with DPPH· scavenging activity, ABTS + scavenging activity, and reducing power. Generally, fine grind and 80% acetone extract showed averaged highest values in antioxidant activities, total phenolic content, and individual phenolic acid compositions. Stepwise linear regression showed that extract solvent was the most important factor for DPPH· scavenging activity, ABTS + scavenging activity, reducing power, and iron chelating activity. The sum of syringic acid and caffeic acid exhibited a dominant role in explaining the major variation in antioxidant activities except for superoxide anion radical scavenging activity.

Reactivity of flavanols: Their fate in physical food processing and recent advances in their analysis by depolymerization

Flavanols, a subgroup of polyphenols, are secondary metabolites with antioxidant properties naturally produced in various plants (e.g., green tea, cocoa, grapes, and apples); they are a major polyphenol class in human foods and beverages, and have recognized effect on maintaining human health. Therefore, it is necessary to evaluate their changes (i.e., oxidation, polymerization, degradation, and epimerization) during various physical processing (i.e., heating, drying, mechanical shearing, high-pressure, ultrasound, and radiation) to improve the nutritional value of food products. However, the roles of flavanols, in particular for their polymerized forms, are often underestimated, for a large part because of analytical challenges: they are difficult to extract quantitatively, and their quantification demands chemical reactions. This review examines the existing data on the effects of different physical processing techniques on the content of flavanols and highlights the changes in epimerization and degree of polymerization, as well as some of the latest acidolysis methods for proanthocyanidin characterization and quantification. More and more evidence show that physical processing can affect content but also modify the structure of flavanols by promoting a series of internal reactions. The most important reactivity of flavanols in processing includes oxidative coupling and rearrangements, chain cleavage, structural rearrangements (e.g., polymerization, degradation, and epimerization), and addition to other macromolecules, that is, proteins and polysaccharides. Some acidolysis methods for the analysis of polymeric proanthocyanidins have been updated, which has contributed to complete analysis of proanthocyanidin structures in particular regarding their proportion of A-type proanthocyanidins and their degree of polymerization in various plants. However, future research is also needed to better extract and characterize high-polymer proanthocyanidins, whether in their native or modified forms.

Differences in Leaf Chemistry and Glandular Trichome Density between Wild Southwestern American Hop (Humulus neomexicanus) and Commercial Hop Cultivars

The female flowers ("cones") of the hop plant (Humulus L.) produce compounds that contribute to the flavor and other properties of beer. Hop leaves and cones produce many of the same compounds, which also confer agronomic traits such as insect and disease resistance. Targeted and untargeted ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry with Waters MS^E technology (UPLC-QTof-MS^E) metabolomics were used to compare leaf phytochemical compositions of greenhouse-grown southwestern American wild Humulus neomexicanus (A. Nelson and Cockerell) Rydb. against a group of commercial hop cultivars consisting of both pure European Humulus lupulus L. and European-North American hybrids. Principal component analysis showed a clear distinction in chemical profiles between the two groups. H. neomexicanus leaves had a significantly higher content of total α acids (p = 4.4 × 10^-9), total bitter acids (p = 2.6 × 10^-6), cohumulone (p = 1.0 × 10^-13), humulone + adhumulone (p = 9.1 × 10^-4), and the prenylflavonoids xanthohumol (p = 0.013) and desmethylxanthohumol (p = 0.029) as well as significantly higher densities of glandular trichomes (p = 1.3 × 10^-6), the biosynthetic site of those compounds. Most flavonol glycosides measured were also significantly more abundant in H. neomexicanus (p = 1.5 × 10^-22 to 0.0027), whereas phenolic acids were consistently, but generally nonsignificantly (p > 0.05), more abundant in the cultivars. The higher bitter acid, prenylflavonoid, and flavonol glycoside content of H. neomexicanus leaves may help to confer more favorable insect and disease-resistance properties.

Beer Polyphenols—Bitterness, Astringency, and Off-Flavors

The acceptance of beer among consumers is most influenced by the taste and aroma. Polyphenols are widely responsible for both. Whereas polyphenols do not always result in a positive flavor and taste, they can surely impart certain off-flavors, which will be mentioned in this paper. However, the aftertaste is an important component of the beer-tasting experience and acceptance. The aftertaste, including astringency, may largely influence consumers’ consumption preference and behavior. Bitterness is one of the main, desirable characteristics of beer, but to an untrained consumer, it can often be mistaken with astringency. This review aims to describe the differences between these two properties. Both attributes derive from the same beer components, polyphenols from barley and hop, but there is a distinctive difference between them. To understand the complexity of bitterness and astringency, polyphenols behavior, characteristics, and stability during the brewing process are also described in this review.

Systemically Achievable Doses of Beer Flavonoids Induce Estrogenicity in Human Endometrial Cells and Cause Synergistic Effects With Selected Pesticides

Some prenylated polyphenols originating from hops, which are thus natural constituents of beer, have been discussed critically for their agonistic potential toward estrogen receptors. So far, little attention has been attributed to the fact that humans are typically not exposed to isolated compounds, but to mixtures which for example might comprise in addition to hop flavonoids further xenoestrogens, e.g., certain pesticides used for plant protection of hops and barley. Thus, we used the alkaline phosphatase assay to assess combinatory estrogenic effects of three signature compounds – xanthohumol, 8-prenylnaringenin and iso-xanthohumol–on Ishikawa cells in a combination that resembled the concentration ratios observable in beer. Moreover, we added this natural flavonoid pattern to a mixture of representative estrogenic pesticides to assess their combined effects. Using state-of-the-art statistical tools, we observed cumulative to slightly synergistic effects between isolated flavonoids as well as the flavonoid and the pesticide mixture. Of potential importance, these effects were found at low nanomolar hop polyphenol concentrations that one can reasonably expect to occur in vivo after the consumption of strongly hopped beer. Taken together, our results imply that cumulative/synergistic estrogenicity should be explored in detail and urgently be incorporated into risk assessment of prenylated chalcones.

Physico-Chemical and Sensory Characterization of a Fruit Beer Obtained with the Addition of Cv. Lambrusco Grapes Must

In 2015, Italian Grape Ale (IGA) beers have been included as a new provisional sub-category of special-type fruit beers by the Beer Judge Certification Program, including those products whose brewing process is carried out in presence of determined quantities of grape must. However, information on the effects of these additions on the composition of final beers are still scarce. This work is hence focused on the chromatic, volatile, phenolic and sensory characterization of IGA beers obtained with the addition of grape musts during brewing process. To this aim, different amounts of must (5, 10 and 20%) from cv. Lambrusco red grapes were added to a lager wort before primary fermentation. Beers were then characterized by HPLC-MS, GC-MS and sensory analysis in order to determine phenolic and aroma compounds along with their sensory attributes. Results confirmed the addition of must from cv. Lambrusco grapes capable to enrich beers in color, acids, phenolic (up to 7-folded increased) and volatile compounds, while giving complexity to beers. These results, which were confirmed by a trained sensory panel, are among the very first insights on the impact of red grape must in brewing, both from a compositional and sensory point of view.

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.

Research of hop polyphenols impact on malt hopped wort aroma formation model experiments

Currently, a lot of research is being done on the flavoring compounds of hops. However, much less attention has been paid to the aroma formation considering the hop polyphenol different groups by various methods at the wort hopping stage. Therefore, the main goal of the research is an impact of hopping conditions on the polyphenolic compounds, when the hop is extracted variously into both wort and water to better understand extraction conditions, mechanisms, and factors as well as aroma formation considering various groups of polyphenols. As shown the hop variety, boiling time, and treatment type affect the hop polyphenols amount extracted into the wort. Aromatics varied upon a hop variety and wort boiling time accompanying a positive softening effect regarding aroma formated from malt wort compounds comparing to hopped aqueous extracts. The research proved the most noticeable pH (7 and above) impact on aroma formation caused by the polyphenol conversion. As also shown the first time, a temperature and acidic pH doubled the rutin amount, as well as the best extraction of the prenylflavanoid isoxanthohumol, was achieved by boiling at an alkaline medium pH. The results obtained indicate that various hydrophilic amino acids containing in the wort can stabilize polyphenols affecting the quality indicators of beer produced from different grain raw materials.

Impact of Dealcoholization by Osmotic Distillation on Metabolic Profile, Phenolic Content, and Antioxidant Capacity of Low Alcoholic Craft Beers with Different Malt Compositions

Beer antioxidants originate mainly from malts, classified as colored, caramel, and roasted, according to the malting process. This study aimed to characterize, in terms of phenolic antioxidants, three types of Pale Ale craft beers brewed using increasing percentage of dark malt (0, 5, and 15% Caraamber malt, called PA100, PA95, PA85, respectively) and to evaluate the impact of dealcoholization by osmotic distillation (OD) on the same antioxidants. All the alcoholic (PA, 6.2-6.8 vol %) and low alcoholic (LA-PA, 1 vol %) beers were analyzed by HPLC-ESI-MS/MS, total phenolic content (TPC), and antioxidant activity (AA): similar phenolic profiles were evidenced and 43 compounds identified or tentatively identified. Some differences were found among PA100, PA95, and PA85: PA85 was richer in free phenolic compounds (10.55 mg/L) and had a higher TPC (463.7 GAE mg/L) and AA (852.1 TE mg/L). LA-PA beers showed the same phenolic profile and similar TPC and AA compared to PA beers; however, there were some differences regarding LA-PA85 (5.91 mg/L). Dealcoholization by OD seemed to weakly affect the phenolic fraction. ESI-MS/MS infusion experiments evidenced oligosaccharides, small organic acids, and amino acids, whose presence was confirmed and quantitated by NMR: besides ethanol and other alcohols, weak to strong loss of low-molecular-weight metabolites was evidenced in LA-PA beers.

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.

Impact of germination on the chemical profile of HomChaiya rice wort and beer

HomChaiya rice is one of the important rice varieties in Thailand. However, the commercial value of this rice is very limited as it is not widely known and has limited availability. The present research aimed to produce an alcoholic beverage from malted HomChaiya rice, and various chemical profiles (physicochemical, phytochemicals, volatiles, and amino acids) were studied. HomChaiya rice was germinated for different periods (3, 5, and 7 days), kilned at 60 °C, and used to produce wort and beer. Physicochemical qualities such as pH, brix, titratable acidity, viscosity, soluble nitrogen, FAN, and extractability were higher in the wort, and the results were significantly influenced by the germination time. On the other hand, the color values were higher in the beer samples, and prolonged germination brightened the beer color. The total phenolic content, flavonoid content, and various antioxidant potentials (DPPH, ABTS, and reducing power) were significantly increased in the beer samples when made with rice malt germinated for 7 days compared to the wort under similar conditions. Wort samples had 13 identified volatiles, whereas the beer samples had 30 volatile compounds. Furthermore, 20 amino acids were identified, and most of them were found at a higher level in the wort samples compared to beer samples, and prolonged germination slightly increased the amino acid levels. The beer samples' sensory characteristics showed that the HomChaiya rice germination period had no significant effect.

An alcoholic beverage from malted HomChaiya rice was produced and various chemical profiles and sensory characteristics were studied.

Observations on the Malting of Ancient Wheats: Einkorn, Emmer and Spelt

There have been tremendous marketing efforts and consumer interest in the so-called ancient grains. Einkorn, emmer and spelt, which are sometimes referred to as ancient wheats, are frequently included in this category, and have gained some attention among brewers. The objective of the current study was to compare the malting behavior and quality of einkorn, emmer and spelt cultivars obtained from the same growing environment. Aside from standard malt quality traits, the levels of β-amylase, protease, xylanase, wort arabinoxylans and wort phenolic acids were measured. While protein levels of the samples were higher (11.4–14.0%) than normally selected for wheat malt, the results indicated that malts of acceptable quality in terms of extract and amylolytic activity can be prepared from the three grain types. However, the ideal malting protocol will likely differ between the grains. The kernels of einkorn are significantly smaller, and steep hydration and malt modification are quicker. In terms of potential health benefits from antioxidant capacity and dietary fiber, wort from einkorn trended to higher levels of free and conjugated ferulic acid, as well as high-molecular-weight arabinoxylan.

Functionality of Special Beer Processes and Potential Health Benefits

Consumers’ demand for functional fermented food that can fulfill nutritional needs and help maintain a balanced diet while also having a positive impact on one’s health status is increasing all over the world. Thus, healthy choices could include beverages with nutrients and bioactive compounds which can be used as an effective disease-prevention strategy. Regular beer has certain health benefits which inspire further research with the prospect of obtaining special functional beers with little or no alcohol content. As observed, the special beer market remains highly dynamic and is predicted to expand even further. Therefore, brewers need to keep up with the consumers’ interests and needs while designing special beers, namely nonalcoholic beers (NABs), low-alcohol beers (LABs), and craft beers (CBs). Thus, understanding the potential uses of bioactive compounds in special beer, the wide range of therapeutic effects, and the possible mechanisms of action is essential for developing healthier beverages. This review aimed to evaluate the nutritional features of special beers, and their proven or potential beneficial actions on one’s health status and in preventing certain diseases.

Non-Alcoholic and Craft Beer Production and Challenges

Beer is the most consumed alcoholic beverage in the world and the third most popular beverage after water and tea. Emerging health-oriented lifestyle trends, demographics, stricter legislation, religious prohibitions, and consumers’ preferences have led to a strong and steady growth of interest for non-alcoholic beers (NABs), low-alcohol beers (LABs), as well for craft beers (CBs). Conventional beer, as the worlds most consumed alcoholic beverage, recently gained more recognition also due to its potential functionality associated with the high content of phenolic antioxidants and low ethanol content. The increasing attention of consumers to health-issues linked to alcohol abuse urges breweries to expand the assortment of conventional beers through novel drinks concepts. The production of these beers employs several techniques that vary in performance, efficiency, and usability. Involved production technologies have been reviewed and evaluated in this paper in terms of efficiency and production costs, given the possibility that craft brewers might want to adapt them and finally introduce novel non-alcoholic drinks in the market.

Unraveling the Antioxidant, Binding and Health-Protecting Properties of Phenolic Compounds of Beers with Main Human Serum Proteins: In Vitro and In Silico Approaches

Our recently published in vivo studies and growing evidence suggest that moderate consumption of beer possesses several health benefits, including antioxidant and cardiovascular effects. Although beer contains phenolic acids and flavonoids as the major composition, and upon consumption, the levels of major components increase in the blood, there is no report on how these beer components interact with main human serum proteins. Thus, to address the interaction potential between beer components and human serum proteins, the present study primarily aims to investigate the components of beer from different industrial sources as well as their mode of interaction through in silico analysis. The contents of the bioactive compounds, antioxidant capacities and their influence on binding properties of the main serum proteins in human metabolism (human serum albumin (HSA), plasma circulation fibrinogen (PCF), C-reactive protein (CRP) and glutathione peroxidase 3 (GPX3)) were studied. In vitro and in silico studies indicated that phenolic substances presented in beer interact with the key regions of the proteins to enhance their antioxidant and health properties. We hypothesize that moderate consumption of beer could be beneficial for patients suffering from coronary artery disease (CAD) and other health advantages by regulating the serum proteins.

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.

Chemometric modeling of palate fullness in lager beers

Palate fullness and mouthfeel of beer are key attributes of sensory beer quality. Non-volatile substances and molar mass fractions influence sensory perceptions of palate fullness and mouthfeel. However, systematic correlations between sensory attributes and native beer compounds have not been evaluated within the concentration range found in lager beer. This article reports a chemometric analysis of 41 lager beers by evaluating analytical data of beer compositions, palate fullness, and mouthfeel descriptors. AF4-MALS-dRI indicated high variability in the macromolecular compositions of classical lager beers. Screened beers were clustered into groups differing significantly in palate fullness intensity and macromolecular distribution. Significant correlations were found between palate fullness and macromolecular fractions and beer composition parameters: original gravity, viscosity, indices of macromolecular distribution, total nitrogen (p < 0.001), and β-glucan (p < 0.01). Thus, a model was built using partial least square regression (PLS) analysis to predict the palate fullness intensity in beers (R²_C = 0.7993). This model can be used as a guideline by brewers to control palate fullness and mouthfeel.

Beer components and their beneficial effect on the hemostasis and cardiovascular diseases- truth or falsehood

Beer is one of the most widely consumed alcoholic beverages in the world; however, traditional - and non-alcoholic beer consumption appear to have different effects on the cardiovascular system. In this short work, we review a base of recent papers to confirm whether, or not, moderate consumption of beer and its non-alcoholic components have a beneficial effect of cardiovascular system. Moreover, the present work reviews recently published papers regarding the influence of beer components on the hemostasis, cardiovascular system, and cardiovascular diseases (CVDs). Although most nutritional guidelines recommend a maximum of one beer per day for women and two for men, individual ideals may vary according to age, sex, genetics and body type, as well as drug or supplement use. Moreover, the recommendations for the moderate consumption of beer are often based on individual case reports and often small clinical experiments. In addition, as the health-related effects of beer consumption may also depend on the presence of other dietary components, as well as the type of beer, it is difficult to determine whether moderate consumption is universally safe and beneficial for the cardiovascular system. More randomized clinical trials are needed to determine this. Well-designed clinical trials are also required to determine the influence of various beer components on hemostasis and CVDs, and their effects in combination with drug or supplement therapy.