Gluten-Free Brewing: Issues and Perspectives

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.

Evaluation of Gluten Protein Profiles in Hydrolyzed Food Products by a Multiplex-Competitive Enzyme-Linked Immunosorbent Assay

The apparent gluten concentration profiles of 47 hydrolyzed foods (barley malt, sprouted grains, and hydrolyzed wheat proteins (HWP)) were evaluated using a multiplex-competitive ELISA that utilizes the G12, R5, 2D4, MIoBS, and Skerritt antibodies from commercial sources. Cluster analysis was conducted to evaluate similarities or differences in the gluten protein/peptide response profiles among the hydrolyzed foods and their similarities or differences with fermented foods analyzed previously by the ELISA. The gluten protein/peptide response profiles of the hydrolyzed foods mainly depended on the grain source (wheat, rye, or barley) of gluten. Some hydrolyzed foods presented profiles similar to those of certain fermented foods (e.g., barley malt and gluten reduced barley beers), whereas others presented unique profiles (e.g., HWP and sprouted wheat). Additional analysis using wheat gluten-incurred yogurts indicated that while not suitable for the barley- or rye-containing foods tested, a newly developed gluten-incurred yogurt calibrant shows promise for the possible use in the quantitation of several wheat-containing fermented and hydrolyzed foods.

Development of gluten-free craft beer: Impact of brewing process on quality attributes and consumer expectations for sensory properties

To date, few studies investigated the differences between the two main gluten-free (GF) brewing techniques, such as the use of enzymes and the use of unconventional GF grains in brewing, by consumer perspective. In this study a GF beer brewed with sorghum and quinoa, as brewing adjuncts, was compared to the enzymatic-treated counterpart, in order to evaluate the effect of deglutinization treatment on physicochemical, volatile, and sensory characteristics of final beer. Moreover, the influence of brewing process and raw materials information on consumers' sensory perceptions, willingness to buy (WTB) and willingness to pay (WTP) was also investigated (n = 105 consumers), under blind (B), expected (E), and informed (I) conditions. The enzymatic-treated sample showed comparable physicochemical attributes with the untreated counterpart, except for a significant reduction in color and foam stability (p < 0.05). Non-significant difference between samples was found in the overall liking, WTB, and WTP mean scores in all three sensory test conditions (p > 0.05). The information about the deglutinization treatment had a negative impact on overall liking (p < 0.01), although WTP for both samples was significantly higher in the informed test than in blind condition (p < 0.05). Overall, Check-All-That-Apply test results confirmed that the deglutinization treatment does not affect the beer sensory profile, even if the information about brewing ingredients and technologies may slightly influence the consumers' sensory perception. Therefore, this result proves that it is possible to produce a marketable GF beer, simply by partially replacing 40% of barley malt with unconventional GF grains, without using enzymes for gluten reduction purpose.

Characteristics of Oat and Buckwheat Malt Grains for Use in the Production of Fermented Foods

Malted gluten-free cereal grains and pseudo-cereals are interesting raw materials for producing fermented foods. The aim of the work was to assess selected technological quality characteristics and antioxidant properties of special malts in terms of use in the production of fermented foods. The research material consisted of malts made from oat, buckwheat, and brewing barley. Malting was performed on a microtechnical scale according to the standard scheme for brewing barley grain. The basic quality parameters of cereal grains obtained malts, and laboratory wort were assessed according to methods applicable in brewing. Atypical brewing malts were characterized by parameters such as malt extractability, protein solubilization, diastatic force, mash filtration time, and wort viscosity. The best results, comparable to barley malt, were obtained for naked oat malt. Malted buckwheat grains turned out to be the least biochemically modified, although their use in the production of beer and/or other fermented beverages is supported by the high content of bioactive substances and antioxidant potential. As the malting process of cereal plants improves their antioxidant properties and increases their nutritional value, oat and buckwheat malts can be successfully used to produce gluten-free fermented beverages or as an addition to fermented products, e.g., in baking and confectionery.

Microscopic assessment of the degradation of millet starch granules by endogenous and exogenous enzymes during mashing

The high gelatinization temperature (GT) of millet starch prevents the usage of infusion or step mashes as an effective means to generate fermentable sugars (FS) in brewing because the malt amylases lack thermostability at GT. Here, we investigate processing modifications to determine if millet starch can be efficiently degraded below GT. We determined that producing finer grists through milling did not introduce enough granule damage to markedly change gelatinization characteristics, though there was improved liberation of the endogenous enzymes. Alternatively, exogenous enzyme preparations were added to investigate their ability to degrade intact granules. At the recommended dosages (0.625 μL/g malt), significant FS concentrations were observed, although at lower concentrations and with a much-altered profile than possible with a typical wort. When exogenous enzymes were introduced at high (10×) addition rates, significant losses of granule birefringence and granule hollowing were observed well below GT, suggesting these exogenous enzymes can be utilized to digest millet malt starch below GT. The exogenous maltogenic α-amylase appears to drive the loss of birefringence, but more research is needed to understand the observed predominate glucose production.

Starch Structure of Raw Materials with Different Amylose Contents and the Brewing Quality Characteristics of Korean Rice Beer

This study aimed to explore suitable processing materials for rice beer (RB) production by analyzing the starch structure of the raw materials utilized for brewing beer and the quality characteristics of RB. We used malt, employing the Heugho cultivar as the main ingredient, and produced beer containing 30% rice. The regular amylose-containing cultivars Samgwang (SA) and Hangaru (HA) and the high-amylose-containing cultivar Dodamssal (DO) were used as adjuncts. Distribution of the short molecular chains of the starch amylopectin was the highest for SA and malt at 29.3% and 27.1%, respectively. Glucose content was the highest in the wort prepared with 100% malt and 30% SA + 70% malt. The alcohol content in SA RB and HA RB was higher than that in beer prepared with 100% malt. DO RB had the least bitterness and volatile components, such as acetaldehyde and ethyl acetate. The three rice cultivars tested in this study are suitable as starch adjuncts for RB production. The characteristics of RBs varied depending on the molecular structure of the ingredients, irrespective of their amylose contents. SA could be considered a craft beer with quality characteristics and rich flavor components, similar to 100% malt beer, compared to other RBs.

A Comprehensive Comparison of Gluten-Free Brewing Techniques: Differences in Gluten Reduction Ability, Analytical Attributes, and Hedonic Perception

This study provides a comprehensive comparison among the most common gluten-free (GF) brewing practices, with a focus on the impact of each treatment on physicochemical parameters and consumer acceptability of the final beer. In addition, the influence of a longer cold maturation on the natural reduction of the gluten content was investigated. Prolyl endopeptidase addition was found to be the most effective treatment in reducing gluten levels (−75.93%), followed by silica gel (−53.09%), longer cold maturation (−4.32%), and tannins (−1.85%). Nonetheless, none of the treated beer samples was gluten-free (gluten content > 20 ppm) due to the high nitrogen content of the original wort. The silica gel application treatment affected the physicochemical and sensory characteristics of the final beer the least. According to the difference from control test results, no significant difference in terms of overall liking, appearance, odor/aroma, or taste was observed between the silica gel-treated sample and control beer (p > 0.05). On the other hand, the application of enzymes and tannins significantly affected the appearance and the beer odor/aroma. Nevertheless, all beer samples received positive sensory acceptance scores.

Physicochemical Characteristics of Bambara Groundnut Speciality Malts and Extract

Speciality malts and their extracts have physicochemical characteristics such as colour, flavour, and aroma sorted for in food production. Speciality malts used in food production are mostly produced from cereal grains. Hence, this study aimed to produce speciality malts from Bambara groundnut (BGN) seeds and analyse their physicochemical characteristics and metabolites. The base, toasted, caramel, and roasted malt were produced by drying at different temperatures and times. Syrups were produced isothermally from the speciality malts. The speciality malts and syrups were assessed for colour, pH, protein, α and β-amylases, total polyphenols, antioxidants, and metabolite profiling. The BGN speciality malts were assayed for fatty acid methyl esters (FAME), hydrocarbons, sugar alcohols, sugars, acids, amino acids, and volatile components using capillary gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionisation detection (GC-FID). The colours of the speciality malts and syrups were significantly (p = 0.000) different. The protein content of the BGN speciality malts was significantly different (p = 0.000), while the protein content of the syrups was not significantly different. The amylase activities of the BGN speciality malt decreased with the change in kilning temperatures and time. The α- and β-amylase activities for the specialty malts were 1.01, 0.21, 0.29, 0.15 CU/g and 0.11, 0.10, 0.10, 0.06 BU/g. The total polyphenols and antioxidant activities differed for all BGN speciality malts. There were twenty-nine volatiles detected in the BGN speciality malts. Fifteen amino acids consisted of seven essential amino acids, and eight non-essential amino acids were detected in the speciality malts. Fatty acid methyl esters (FAME) identified were palmitoleic, oleic, linolelaidic, linoleic, and arachidic acid. The sugars, organic acids, and sugar alcohols consisted of lactic acid, fructose, sucrose, and myo-inositol. The BGN speciality malts exhibited good physicochemical characteristics and metabolites that can make them useful as household and industrial ingredients for food production, which could be beneficial to consumers.

Buckwheat and Amaranth as Raw Materials for Brewing, a Review

Globally, beer is considered the most-consumed low-alcohol beverage, it ranks third, after water and tea, in the top sales of these drinks. New types of beer are the result of the influence of several factors, including innovations in science and technology, changing requirements for food consumption of the population, competition between producers, promotion of food for health, flavor, and quality, the limited nature of traditional food resource raw materials, and the interest of producers in reducing production costs. Manufacturers are looking for new solutions for obtaining products that meet the requirements of consumers, authentic products of superior quality, with distinctive taste and aroma. This review proposes the use of two pseudocereals as raw materials in the manufacture of beer: buckwheat and amaranth, focusing on the characteristics that recommend them in this regard. Due to their functional and nutraceutical properties, these pseudocereals can improve the quality of beer-a finished product. Additionally, all types of beer obtained from these pseudocereals are recommended for diets with particular nutritional requirements, especially gluten-free diets. Researchers and producers will continue to improve and optimize the sensory and technological properties of the new types of beer obtained from these pseudocereals.

Modeling in Brewing—A Review

Beer production has over a thousand-year tradition, but its development in the present continues with the introduction of new technological and technical solutions. The methods for modeling and optimization in beer production through an applied analytical approach have been discussed in the present paper. For this purpose, the parameters that are essential for the main processes in beer production have been considered—development of malt blends, guaranteeing the main brewing characteristics; obtaining wort through the processes of mashing, lautering and boiling of wort; fermentation and maturation of beer. Data on the mathematical dependences used to describe the different stages of beer production (one-factor experiments, modeling of mixtures, experiment planning, description of the kinetics of microbial growth, etc.) and their limits have been presented, and specific research results of various authors teams working in this field have been cited. The independent variables as well as the objective functions for each stage have been defined. Some new trends in the field of beer production have been considered and possible approaches for their modeling and optimization have been highlighted. The paper suggests a generalized approach to describe the main methods of modeling and optimization, which does not depend on the beer type produced. The proposed approaches can be used to model and optimize the production of different beer types, and the conditions for their application should be consistent with the technological regimes used in each case. The approaches for modeling and optimization of the individual processes have been supported by mathematical dependencies most typical for these stages. Depending on the specific regimes and objectives of the study, these dependencies can be adapted and/or combined into more general mathematical models. Some new trends in the field of beer production have been considered and possible approaches for their modeling and optimization have been highlighted.

Beer and Allergens

Food allergies are an important global health concern, with many countries following the World Health Organisation’s guidelines with regards to due labelling of foods and, as such, providing forewarning about the presence of potential allergens to potential consumers. While for some produce, the link to specific allergens might be very clear to most consumers, this is not the case for all produce. People with specific food-related allergies usually know what to look out for, but occasionally, unexpected allergens are present in trusted produce. Beer is known to most to contain barley, which will contain gluten-like proteins that can cause allergic reactions in some people. Similarly, beer might contain sulphites and other potential allergens traditionally associated with beers. This review aims to examine a wide range of allergens that have entered the beer production process in recent years. As a result, examples of beers that contain one or more of the 14 EU-UK listed allergens are described, different allergen regulations in different countries are emphasised and their impact explained, and a number of case studies involving allergic reactions following exposure to and the ingestion of beer are highlighted.

Development of an Araucaria araucana Beer-like Beverage: Process and Product

The seed from the Araucaria araucana (in Spanish, piñon) tree, native to Chile and Argentina, is sold mainly as raw seed. Engineering a process to add value to piñon has the potential to positively impact local indigenous communities with very little ecological impact because it is routinely harvested in the wild. This study evaluated the feasibility of using 100% piñon, or as a blend with barley malt, to produce a beer-like beverage, while also evaluating consumer acceptance of the beverage’s piñon characteristics. Prototypes generated based on 93% piñon and 7% oat (enzymatic treatment of α-amylase, glucoamylase, protease and β-glucanase), as well as 50% piñon and 50% barley (no external enzymatic treatment), were evaluated. Overall acceptability by a consumer acceptance panel (21 consumers) rated the 100% piñon and the piñon–barley malt blend 5/9 and 7/9, respectively. The piñon–barley malt blend prototype stood out for its low level of carbohydrates, high potassium content and banana and clove aromas.

Autochthonous Biological Resources for the Production of Regional Craft Beers: Exploring Possible Contributions of Cereals, Hops, Microbes, and Other Ingredients

Selected biological resources used as raw materials in beer production are important drivers of innovation and segmentation in the dynamic market of craft beers. Among these resources, local/regional ingredients have several benefits, such as strengthening the connection with territories, enhancing the added value of the final products, and reducing supply costs and environmental impacts. It is assumed that specific ingredients provide differences in flavours, aromas, and, more generally, sensory attributes of the final products. In particular, of interest are ingredients with features attributable and/or linked to a specific geographical origin. This review encompasses the potential contribution and exploitation of biodiversity in the main classes of beer inputs, such as cereals, hops, microbes, and adjuncts, with a specific emphasis on autochthonous biological resources, detailing the innovative paths already explored and documented in the scientific literature. This dissertation proposes an overview of the impact on beer quality for each raw material category, highlighting the benefits and limitations that influence its concrete applications and scale-up, from the field to the stain. The topics explored promote, in the sector of craft beers, trends already capitalised in the production of other alcoholic beverages, such as the preservation and revalorisation of minor and autochthonous varieties, the exploitation of yeast and bacteria strains isolated from specific sites/plant varieties, and the valorisation of the effects of peculiar terroirs on the quality of agricultural products. Finally, the examined tendencies contribute toward reducing the environmental impacts of craft beer manufacturing, and are in line with sustainable development of food systems, increasing the economic driver of biodiversity preservation.

Brewing with Starchy Adjuncts: Its Influence on the Sensory and Nutritional Properties of Beer

In brewing, the use of cereals (wheat, barley, maize, rice, sorghum, oats, rye or millet), pseudo-cereals (buckwheat, quinoa or amaranth) and tubers (sweet potato), as starch adjuncts, is being promoted for the production of a variety of high-quality beers, from sensory and nutritional points of view. The sensory properties of the obtained beer depend on the characteristics of each adjunct but also on the forms in which the adjunct is added: whole cereal, grits, malted, extruded grains, torrefied and syrup. Among these common forms, the extruded grains (maize or rice) produce a higher content of aroma compounds in beer. From a nutritional point of view, the use of non-conventional starch adjuncts, such as black rice, buckwheat or sweet potato, leads to an increase in the polyphenol content of the beer, and thus, its antioxidant capacity. Cereals such as maize, rice, sorghum or millet are the most promising for the production of gluten-free beers. A close relationship can be developed between the use of adjuncts in the beer industry and the use of commercial enzymes. Advances made by biotechnology to design new enzymes with different functionalities could be associated to a future increase in adjunct usage in brewing.

Recent innovations in the production of selected specialty (non-traditional) beers

Customer demand for product diversity is the key driving force for innovations in the brewing industry. Specialty beers are regarded as a distinct group of beers different from two major types, lagers and ales, without established definitions or boundaries. Specialty beers, including low- to no-alcohol beer, low carbohydrate beer, gluten-free beer, sour beer, probiotic beer, and enriched beer, are exclusively brewed and developed keeping in mind their functionality, the health and wellbeing of the consumer, and emerging market trends. Compared with conventional beer-brewing, the production of specialty beers is technologically challenging and usually requires additional process steps, unique microorganisms, and special equipment, which in turn may incur additional costs. In addition, the maintenance of quality and stability of the products as well as consumer acceptability of the products are major challenges to successful commercialization. A harmonious integration of traditional brewing practices and modern technological approaches may hold potential for future developments. In the present review, latest developments in the fermentative production of selected specialty beers are discussed.

Maize and Sorghum as Raw Materials for Brewing, a Review

Brewing is among the oldest biotechnological processes, in which barley malt and—to a lesser extent—wheat malt are used as conventional raw materials. Worldwide, 85–90% of beer production is now produced with adjuvants, with wide variations on different continents. This review proposes the use of two other cereals as raw materials in the manufacture of beer, corn and sorghum, highlighting the advantages it recommends in this regard and the disadvantages, so that they are removed in technological practice. The use of these cereals as adjuvants in brewing has been known for a long time. Recently, research has intensified regarding the use of these cereals (including in the malted form) to obtain new assortments of beer from 100% corn malt or 100% sorghum malt. There is also great interest in obtaining gluten-free beer assortments, new nonalcoholic or low-alcohol beer assortments, and beers with an increased shelf life, by complying with current food safety regulations, under which maize and sorghum can be used in manufacturing recipes.

Characteristic changes in malt, wort, and beer produced from different Nigerian rice varieties as influenced by varying malting conditions

Gluten-free beer could be produced with rice, although the latter would primarily serve as adjunct in combination with barley malt in today’s brewing. However, the recent growing realisation of the potential and applications of rice malt for brewing an all-rice malt beer through varying malting conditions cannot be overlooked. In this study, therefore, the characteristic changes in malt, wort, and beer from different Nigerian rice varieties (FARO 44, FARO 57, NERICA 7) as influenced by varying malting conditions (steeping duration (18, 24 and 30 h), germination periods (2, 3 and 4 days) and kilning temperatures (50 and 55 °C)), were investigated. Rice (grain) samples were examined by thousand kernel weight (TKW), germinative energy (GE), germinative capacity (GC), and degree of steeping (DoS). To ensure that rice wort/beer with unique beer style and enhanced attributes, comparable to barley wort/beer is produced, malting conditions that produced rice malts with peak diastatic power (DP), cold water extract (CWE), and hot water extract (HWE) were selected. Peak DP, CWE and HWE were obtained at FARO 44 (18 h steeping, 3 days germination, 55 °C kilning (S₁₈G₃K_55°)), FARO 57 (30 h steeping, 2 days germination, 50 °C kilning (S₃₀G₂K_50°)) and NERICA 7 (24 h steeping, 3 days germination, 55 °C kilning (S₂₄G₃K_55°)). Selected malts were further tested for moisture content, total nitrogen, malt yield and malting loss and subsequently progressed to wort and beer production. Wort’s pH, total soluble nitrogen (TSN), brix, kolbach index (KI), free amino nitrogen (FAN), dextrose equivalent (DE), original extract (OE) and sugar profile were determined, as well as beer’s pH, colour, apparent extract (AE), alcohol by volume (%ABV), turbidity and sensory attributes. Rice grain varied significantly (p < 0.05) in TKW, GE, GC and DoS across varieties. Despite wort’s pH, TSN, DE, OE as well as beer pH, colour, AE and turbidity resembling (p > 0.05) across varieties, wort’s brix, KI, FAN, sugar profile as well as beer’s %ABV, differed significantly (p < 0.05). Sensory attributes of appearance, colour, mouthfeel, and overall acceptability in beer differed noticeably (p < 0.05), except for aroma and taste (p > 0.05). Overall, the rice beer, though very slightly hazy, represented a pale yellow light lager, which is indicative of its peculiar beer style. Besides increased DP and enhanced hydrolysis, varying malting conditions of current study could serve as a pathway of reducing the cost of exogenous (commercial) enzymes or barley malt imports, together with decreasing barley’s dependency for brewing in the tropics.

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.

Gluten hypersensitivities and their impact on the production of gluten-free beer

This article consists of a study of the literature and an assessment of available data on the production of gluten-free beer and its constituents. The article shows how the FAO/WHO Codex Alimentarius Commission for Nutrition and Foods for Special Dietary Uses defines celiac disease, gluten-free products, and gluten-free beer. It describes diet-dependent diseases, which require a gluten-free diet, and groups of potential consumers of gluten-free beer. This article describes the use of oats as a raw material for the production of brewing malt and its usefulness in the production of beer. It specifies how the technological process of standard beer production needs to be modified so that the product meets the requirements of patients with celiac disease. The article also provides an overview of literature data on the production of gluten-free beer from pseudocereal malts, such as sorghum malt, buckwheat malt, amaranth malt, and quinoa malt.

Assessment of Volatiles and Polyphenol Content, Physicochemical Parameters and Antioxidant Activity in Beers with Dotted Hawthorn (Crataegus punctata)

Beer with the addition of dotted hawthorn (Crataegus punctata) fruit and juice was prepared and analysed. The content of carbohydrates, glycerol and ethanol in beers was determined by high-performance liquid chromatography (HPLC). Analysis of the total content of polyphenols was also performed using the Folin-Ciocalteu method, as well as determining antioxidant capacity by DPPH^• and ABTS^+• assay, and the ability to reduce iron ions by FRAP assay. Content of volatile compounds was analysed by means of solid-phase microextraction and gas chromatography coupled with mass spectroscopy. Beers with addition of hawthorn, both juice and fruit, had higher antioxidative potential and higher polyphenols concentration compared to control beer. The content of polyphenols in beers was in the range 200.5–410.0 mg GAE/L, and the antioxidant activity was in the range of 0.936–2.04 mmol TE/L (ABTS^+• assay), 0.352–2.175 mmol TE/L (DPPH^• assay) and 0.512–1.35 mmol TE/L (FRAP assay). A sensory evaluation of beers was also carried out. Beer with hawthorn fruit addition obtained the best scores in sensory analysis for criteria such as aroma, taste and overall quality. This beer had the highest content of volatile compounds (287.9 µg/100 mL of beer), while the control beer had lowest concentrations (35.9 µg/100 mL of beer).