Brewer Research Articles

Simultaneous Saccharification and Fermentation of Wheat Starch for Bioethanol Production

Bioethanol is a renewable, environmentally-friendly biofuel conventionally produced through the alcoholic fermentation of sugary or starch-rich substrates by microorganisms, commonly Yeast Saccharomyces cerevisiae. Intermediates of industrial wheat flour wet milling processing to starch, such as A-starch and B-starch milk, are cost-effective, abundant, and non-seasonal feedstocks for bioethanol production. This study evaluates the bioethanol production from wheat A-starch and B-starch milk and mixtures of these two substrates in different ratios (1:3, 1:1, and 3:1) using two cold hydrolysis procedures at 65 °C: (i) simultaneous liquefaction and saccharification (SLS) followed by fermentation, and (ii) liquefaction by alpha-amylase followed by simultaneous saccharification and fermentation (SSF). The results demonstrated that SSF and SLS are equally efficient procedures for reaching a high ethanol yield of 53 g per 100 g of starch and 93% of starch conversion to ethanol for all investigated substrates. Lower levels of non-starch components in A-starch milk, which typically contribute to volatile by-product formation, allowed clear distillate profiles in terms of and lower content of aldehydes, methanol, and volatile acidity, enhancing ethanol distillate purity compared to B-starch milk. Mixing high-quality A-starch milk with low-cost B-starch milk enables higher ethanol yield, improved distillate quality, and energy savings for efficient industrial-scale applications.

Integrated metabolomic and transcriptomic strategies to reveal adaptive mechanisms in barley plant during germination stage under waterlogging stress.

Barley (Hordeum vulgare L.) is an important cereal crop used in animal feed, beer brewing, and food production. Waterlogging stress is one of the prominent abiotic stresses that has a significant impact on the yield and quality of barley. Seed germination plays a critical role in the establishment of seedlings and is significantly impacted by the presence of waterlogging stress. However, there is a limited understanding of the regulatory mechanisms of gene expression and metabolic processes in barley during the germination stage under waterlogging stress. This study aimed to investigate the metabolome and transcriptome responses in germinating barley seeds under waterlogging stress. The findings of the study revealed that waterlogging stress sharply decreased seed germination rate and seedling growth. The tolerant genotype (LLZDM) exhibited higher levels of antioxidase activities and lower malondialdehyde (MDA) content in comparison to the sensitive genotype (NN). In addition, waterlogging induced 86 and 85 differentially expressed metabolites (DEMs) in LLZDM and NN, respectively. Concurrently, transcriptome analysis identified 1776 and 839 differentially expressed genes (DEGs) in LLZDM and NN, respectively. Notably, the expression of genes associated with redox reactions, hormone regulation, and other biological processes were altered in response to waterlogging stress. Furthermore, the integrated transcriptomic and metabolomic analyses revealed that the DEGs and DEMsimplicated in mitigating waterlogging stress primarily pertained to the regulation of pyruvate metabolism and flavonoid biosynthesis. Moreover, waterlogging might promote flavonoid biosynthesis by regulating 15 flavonoid-related genes and 10 metabolites. The present research provides deeper insights into the overall understanding of waterlogging-tolerant mechanisms in barley during the germination process.

Development of a Quinoa‐Based Fermentation Medium for Propagation of Lactobacillus Plantarum and Weissella Confusa in Opaque Beer Production

Product inconsistency of opaque beer has for long been a tenacious problem in the brewing industry since the current process relies on spontaneous lactic acid fermentation. In order to impede this challenge, there is a need to add lactic acid bacteria (LAB) starter cultures in opaque beer brewing to improve its organoleptic qualities. This study sought to develop a quinoa‐based fermentation medium for propagation of Lactobacillus plantarum and Weissella confusa as potential starter cultures in opaque beer production. An evaluation of the stability and tolerance of the LAB under various stress conditions was also done. Fermentation wort from opaque beer brewing and different quinoa‐based synthetic media with varying nutritional components was prepared for propagation of LAB. Physiochemical analyses which included pH, Brix value and total titratable acidity (TTA) of monocultured and cocultured synthetic media were measured. The measurements were done at 24 h time intervals ranging from 0 to 96 h. Tolerance studies which included the effect of heat shock, cold shock, oxidative stress and osmotic pressure on the survival rate of LAB were conducted to determine the stability of LAB. MRS with L. plantarum monoculture (MRSp) had a notable change in pH from 4.5 to 3.6 after 24 h. The cocultured (M5p + w) synthetic media and cocultured MRS (MRSp + w) also exhibited change in pH from 4.3 to 3.2 and 4.3 to 3.3, respectively, after 72 h. Brix value in all media samples decreased after 24 h except for the uninoculated MRS sample (MRS C). The synthetic and coculture medium (M5p + w) exhibited an increase in TTA (0.79% (m/v) lactic acid) within the first 24 h. Exposure to heat shock had a significance effect (p < 0.05) on the survival rate of L. plantarum and W. confusa. The W. confusa in synthetic media recorded a higher survival rate (27 ± 0.03%) upon exposure to heat shock than L. plantarum (7 ± 0.01%). In contrast, L. plantarum in MRS recorded a higher survival rate (67 ± 0.02%) upon exposure to cold shock and oxidative stress (34 ± 0.01%). The starter cultures tested survived upon exposure to the stress conditions, indicating their potential use in opaque beer production.

Cloning of glucoamylase gene from Aspergillus niger and its expression in Pichia pastoris

Glucoamylase (1,4-α-glucosidase) is a crucial commercial enzyme responsible for the conversion of starch, glycogen, and oligosaccharides into D-glucose through the hydrolysis of their non-reducing terminal glycosidic bonds. While many microorganisms, including bacteria, yeasts, and fungi, can produce glucoamylase, fungal glucoamylase is the preferred choice for industrial applications. The goal of this study was to produce the glucoamylase enzyme recombinantly in Pichia pastoris. To achieve this, the glaA gene from Aspergillus niger, responsible for encoding the glucoamylase enzyme, was cloned into a plasmid (pGAPZα-A) under the control of the GAP promoter and subsequently transferred into P. pastoris. The gene was verified through sequence analysis, while the effectiveness of transfection was validated using colony PCR and enzyme activity assays. The results demonstrated that the recombinant P. pastoris strain successfully secreted a substantial amount of glucoamylase (307.05 mg/L). The activity of the recombinant enzyme was measured at 79 U/mL.min. The enzyme exhibited robust activity over a broad range of temperatures (50-80°C) and various pH levels (pH 5-10), retaining 92-60% of its maximum activity. In conclusion, this study highlights the potential for laboratory-scale production of the glucoamylase enzyme, crucial for various industries, from a cost-effective and easily cultivable recombinant yeast strain, P. pastoris.

Impact of Hop Residue Reuse on the Chemical and Sensory Properties of Craft Beer

Hops are an important component of beer brewing, providing aromatic and bittering properties that are essential to consumer appeal. A significant amount of hop residue is generated in the dry-hop brewing process that cannot be reused due to bittering residues that disqualify them as animal feed or other products. The purpose of this research was to reuse four varieties of hop waste (Citra, Mosaic, Hallertau Blanc, and Mandarina Bavaria) through a repalletization process with the objective of integrating them into a new craft beer brewing process. Chemical properties such as the phenolic content, antioxidant capacity, and α- and β-acids were significantly reduced (p < 0.05) due to the reuse of the repelletized hops, leading to a decrease in the bitterness levels in all of the craft beers brewed with dry-hop residues. Finally, the sensory study conducted with non-habitual craft beer consumers revealed significant general acceptability for beers brewed with repelletized dry-hop residues (Mandarina Bavaria, Citra, and Mosaic). The reuse of hop residues for brewing presents a promising opportunity for further development in the food industry.

Optimizing post-harvest processing conditions for Angelica acutiloba roots in Hokkaido: storage temperature and duration.

The traditional post-harvest processing method of Angelica acutiloba roots, which involves hanging the roots outdoors after being harvested, is known to promote the conversion of starch in roots into sucrose, thereby increasing sweetness. At the same time, this method increases the dilute ethanol-soluble extract (DEE) content in A. acutiloba roots to meet the standard set by the Japanese Pharmacopoeia 18th edition. However, in Hokkaido, where A. acutiloba has been cultivated in recent years, it is a challenge to practice this traditional post-harvest processing method owing to the risk of freezing. Therefore, it is necessary to determine post-harvest processing conditions to increase DEE content in A. acutiloba roots in Hokkaido. In this study, we cultivated seedlings in plug trays and the open field in Hokkaido and stored the harvested products at various temperatures and durations to determine changes in DEE content. DEE content immediately after harvest was 20.5% in roots from plug-tray seedlings and 27.8% in roots from seedlings cultivated in the open field. DEE content in roots stored at 0°C increased slowly over 5weeks, whereas that in roots stored at 20°C increased rapidly. We found a strong correlation between DEE content and sucrose content, but not (Z)-ligustilide content. Our findings on the post-harvest processing conditions for roots revealed that the optimal post-harvest processing conditions are storage at 0°C for at least two weeks during which DEE content increases stably, similar to the traditional method.

Beer wheat residue as a probiotic carrier: physicochemical properties via fluid bed granulation (Beer wheat residue for lactic acid bacteria encapsulation).

In recent years, consumer preference for symbiotics containing live bacteria has surged, driven by the acknowledged health benefits. Wheat residue from beer brewing, rich in dietary fiber, remains an unexplored prebiotic raw material for developing vegan probiotic powdered products. Concerns about ambient conditions, dehydration and drying affecting bacterial cell viability prompt the investigation of protective agents (maltodextrin, l-arabinose, casein, whey protein, skimmed milk) and fluidized bed granulation microencapsulation for enhancing the survival rate of Lactiplantibacillus plantarum NKUST 817. The results of the study show that wheat residue, when utilized as the carrier with 10% indigestible dextrin FB06, served as the optimal protective agent. Optimal air inlet temperature (45, 55 and 65 °C) for fluidized bed granulation was investigated along with cell survival rate and probiotic powder characteristics such as moisture, water activity, hygroscopicity, solubility, bulk density and flowability. Bacteria without protective agents showed a survival rate of only 82.63-86.96%. However, the addition of 10% indigestible dextrin FB06 significantly increased in the survival rate of bacteria (granulated at 45-65 °C) to 93.52-95.18%. The microencapsulated bacteria powder exhibited low moisture (2.38-4.36%) and water activity (0.06-0.22). Powder fluidity, indicated by Carr's index (10.87-13.62) and the Hausner ratio (1.13-1.16%), demonstrated good flowability. Furthermore, the powder remained stable for 45 days, with a viable bacteria count of 7.29 log colony-forming units g-1 and a survival rate of 88.69%. This study pioneers vegan probiotic product development at the same time as addressing processing challenges to optimize strain resilience. This research stablishes wheat residue as a suitable candidate for a probiotics carrier. © 2024 Society of Chemical Industry.

The Influence of Sowing Rate and Foliar Fertilization on the Yield of Some Triticale Varieties in the Context of Climate Change in Northwest Romania

Triticale is recognized worldwide because of its high protein and lysine contents, high production capacity, and adaptability to biotic and abiotic stress conditions, these qualities being taken over from wheat and rye. Triticale is widely used in various fields, such as animal feed in various forms, medicine, baking, beer and alcohol brewing, cellulose, bioethanol industry, and many others. Thus, the demand for triticale grain is increasing, and this has led to the research and improvement in culture technology to obtain superior products, both quantitatively and qualitatively. The purpose of this study was to identify the best varieties of triticale cultivated in the northwest of Romania, sown in different plots, and fertilized on the ground. Additionally, this study was carried out over a period of two years at the Livada Agricultural Research and Development Station, Satu Mare County. This study was located on acidic soil with a pH between 5.19 and 6.65 and a humus content of 2.82%. The climatic conditions in the reference period were extremely variable; in the first year, a deficit of more than 90 mm of precipitation was registered, and in the second year of this study, an increase of more than 34 mm. The effects of additional fertilization were influenced by the level of precipitation. In 2023, additional fertilization with foliar fertilizer brought production increases of 884 kg/ha, compared with 2022, where foliar fertilization in drought conditions led to a decrease in production. The Utrifun variety proved to be the most productive; this foliar fertilized and with biostimulator, sown at 550 seeds/m2, recorded an increase in production of over 4500 kg/ha compared with the Negoiu control and sown at 650 seeds/m2 and fertilized with foliar fertilizer had an increase of over 4370 kg/ha compared with the Negoiu control. It recorded a production of 9700 kg/ha sown at 550 seeds/m2 and fertilized only on the soil, and sown at 450 seeds/m2 and additionally fertilized with foliar fertilizer recorded a production of 10.900 kg/ha. Utrifun was followed by Zvelt which, sown at 450 seed/m2 and fertilized on the soil, recorded 9500 kg/ha, ensuring an increase of 1800 kg/ha compared with the Negoiu control. The lowest production was achieved by the Tulnic variety, which is 2022, sown at 650 seed/m2 and fertilized on the ground, recorded 5874 kg/ha, 1621 kg/ha less than the control variant. The increases in production obtained by these varieties will be confirmed in a subsequent study under different climatic conditions.

Lowering the carbon footprint of beer through waste breadcrumb substitution for malted barley: Life cycle assessment and experimental study

Beer is the most produced and consumed alcoholic beverage in the world, but the agricultural production of its most common ingredient, i.e. malted barley, is a significant contributor to the overall environmental footprint of beer. In addition, food wastage, particularly bread with millions of slices wasted daily, poses a waste management challenge across the globe. This study aims to address both issues through brewing beer with waste bread that would have otherwise ended up in landfill by replacing a portion of malted barley with waste bread. A sourdough pale ale was brewed at various bread percentages to understand how the inclusion of bread changed the sugar profile and fermentability of the beer. The samples were mashed at two different temperatures, 65 °C and 70 °C, to assess the impacts of mashing. It was found that the volume of alcohol produced declined with increasing bread amounts, but brewing with up to 60 wt% bread produced the same volume of alcohol as a standard beer. A life cycle assessment was performed to quantify the change in cradle to grave environmental impact for brewing beers with varying bread percentages with the view to conduct more targeted feasibility studies in the future with waste bread substitution. Significant reductions in emissions were observed as regards global warming potential, terrestrial ecotoxicity, acidification, eutrophication, ozone depletion, and abiotic depletion of fossil fuels. In particular, the global warming potential for the real-life example microbrewery studied in this work was decreased by 7.13% of the total carbon dioxide equivalent annually, demonstrating the environmental advantages of brewing beer with waste bread.

Advances in the biosynthesis of D-allulose.

D-allulose is a rare monosaccharide and a C-3 epimer of D-fructose. It has physiological functions, such as antihyperglycemic, obesity-preventing, neuroprotective, and reactive oxygen species (ROS) scavenging effects, making it an ideal sugar substitute. The synthesis methods for D-allulose include chemical synthesis and biosynthesis. Chemical synthesis requires strict reaction conditions and tends to produce byproducts. Biosynthesis is mainly an enzymatic process. Enzymatic catalysis for the conversion of starch or glycerol to D-allulose is performed mainly by enzymes such as isoamylase (IA), glucose isomerase (GI), D-allulose 3-epimerase (DPE), D-allulose-6-phosphate 3-epimerase (A6PE), D-allulose 6-phosphate phosphatase (A6PP), ribitol 2-dehydrogenase (RDH), glycerophosphate kinase (GK), glycerophosphate oxidase (GPO), and dihydroxyacetone phosphate (DHAP)-dependent aldolase. Biosynthesis is a more energy-efficient process, producing fewer harmful by-products and pollutants, and significantly reducing negative environmental impacts. Furthermore, the specific catalytic activity of enzymes facilitates the production of compounds of higher purity, thereby facilitating the isolation and purification of the products. It has thus become the main method for producing D-allulose. This article reviews the progress in research on the biosynthetic production of D-allulose, focusing on the enzymes involved and their enzymatic properties, and discusses the production prospects for D-allulose.

Reassessing the importance of barley starch and amylolytic enzyme properties in malting and brewing.

Efficient conversion of starch to fermentable sugars and dextrins is essential during brewing as it drives process efficiency, resource efficiency, and the quality of the end product. Recent changes in barley growth conditions due to climate change challenge brewers in maintaining these essential aspects of the brewing process. The main component of barley, starch, is also undergoing changes, which can lead to detrimental effects on the brewing process. Additionally, variations in barley genotype and preparatory processing, such as malting, can affect starch properties of the barley malt. These changes in and fluctuations of the raw material barley for brewing have led to recent research focusing on the importance of starch granule proportions, starch structure, and starch behavior as a means to cope with these new challenges. In this review, we summarize the main findings regarding starch properties and behavior from barley to beer, discuss the importance of balancing starch gelatinization and starch hydrolysis during the mashing process, identify research gaps, and suggest potential trajectories for future research.

Exploring the influence of extruded rice adjunct on wort separation efficiency: A bio-macromolecule degradation perspective

Extruded rice adjunct (ERA) possesses promising potential in enhancing brewing efficiency, yet its impact on wort separation performance remains unclear, limiting its utilization in brewing. This study investigated the bio-macromolecule degradation mechanisms in rice adjuncts (RA) and ERA and their influence on wort separation performance, focusing on wort and adjunct residues (ARS) properties. Extrusion enhanced the bio-macromolecule degradation, increasing wort viscosity while reducing ARS complexity. Extrusion also reduced the particle size and modified ARS decomposition, impacting the structure of filter cake (FC). Smaller ERA residues tended to aggregate at the top of FC, leading to a shallower FC depth that facilitated the filtration efficiency and boosted the final wort production. Conversely, the larger compact RA residues settled at the bottom of FC, elevating FC depth and reducing filtration efficiency. Consequently, enhancing bio-macromolecule degradation of adjuncts through extrusion benefits wort filtration and provides valuable insights for ERA utilization in beer brewing.

Restorative Effect of Consuming Red Wine Against Adverse Changes in the Brain of Rodents Exposed to Beer

Objective: There is a surge in the availability of alcoholic products accompanied by a high rate of consumption despite increasing neurological problems. Aim of this study is to determine whether regular intake of brewed beer and red wine affects the microanatomy of the cerebral cortex, hippocampus and brain weight. Materials and Methods: 20 male albino Wistar rats were assigned to four groups of five animals each. Group A, the control was given distilled water; Group B was administered 5 mL/kg body weight of beer; Group C received 5 ml/kg of red wine; and Group D was dosed with 5 ml/kg of beer and followed with 5 ml/kg of red wine. Daily treatments by gavage lasted 15 days, and animal subjects were euthanized via cervical dislocation on day 16. Individual brains were collected and weighed using an electronic scale (SF-400) and afterwards dissected to obtain tissue samples from the cerebral cortex and hippocampus, immediately fixed in 10% formalin for micro-anatomic studies. The paraffin embedding method was used for histological preparation while sections were cut at 5 µm and stained with hematoxylin and eosin. Brain weight was analyzed using the Statistical Product and Service Solutions (SPSS) software via one-way analysis of variance. Results: Histopathological changes including intracerebral haemorrhage and loss of pyramidal neurons observed in group B (beer) samples were not visible in Group D (beer plus red wine), while no microstructural changes occurred in group C (red wine) sections when compared with the control. The output of statistical analysis showed a non-significant reduction in brain weight of group B, whereas a significant increase was noticed in group C while group D showed a non-significant increase. Conclusion: These findings indicate that red wine counteracts beer-induced changes in brain morphology, hypothesising the neuroprotective effect of the wine.

The role of starch digestion in the brewing of gluten-free beers

Celiac disease affects an estimated 1% of the global population, and symptoms are triggered by the consumption of gluten in sensitized individuals. Other gluten sensitivities exist but are poorly characterized or often under-diagnosed, leading a number of people to pursue a gluten-free or gluten-reduced diet even in the absence of a diagnosis. Gluten is a complex suite of proteins from the prolamin fraction of storage proteins in barley, wheat, and rye, meaning that foods or beverages that are produced from these cereals will also contain gluten. Beer is one such beverage that is traditionally produced from malted barley and is thus incompatible with a gluten-free lifestyle. The simplest option to produce a gluten-free beer would seem to be to use alternative, gluten-free, grains such as millet, sorghum, teff, rice, corn or other starchy materials. However, barley has thousands of years of development as a brewing agent behind it and these alternative ingredients cannot be incorporated into the brewing process without substantial alterations. Particularly, these ingredients generally have much lower endogenous starch degrading activity and much higher starch gelatinization temperatures as compared to barley which makes generating sufficient fermentable sugars for yeast fermentation a challenge. In this review we will further elucidate these challenges as well as the solutions that are being developed to bring beer to the gluten-free masses.

Industrial-Level Brewing Using Oenological Saccharomyces cerevisiae and Schizosaccharomyces pombe as Mixed-Inoculum

The development of new food processes and formulations begins at the laboratory stage, progresses through pilot plant trials, and culminates in industrial production. Although the positive effects in terms of sensory characteristics and qualitative differentiation have been widely studied at laboratory level, fermentations conducted at the industrial level by oenological Saccharomyces cerevisiae and non-Saccharomyces strains have not been thoroughly investigated. Scaling up to the industrial level is a critical process that involves more than simply increasing the dimensions of the process itself. The purpose of our research was to compare laboratory and industrial-level brewing of a novel craft beer produced with the addition of common unmalted wheat and fermented by Schizosaccharomyces pombe and S. cerevisiae strains. Fermentation was carried out using a S. cerevisiae strain either of oenological origin alone or through sequential inoculations with S. pombe. Beers produced with the mixed starter showed greater reproducibility between the two production levels than those fermented by S. cerevisiae alone. According to the results, the main differences highlighted between laboratory and industrial-level trials with S. cerevisiae alone concerned the extent of starch degradation, fermentation efficiency, and alcohol production, which were higher in brewing at the laboratory level. In contrast, beers produced at industrial level using sequential inoculation received significantly higher scores for foam quantity and persistence, as well as overall olfactory intensity, while scoring significantly lower scores for saltiness and sourness. To our knowledge, this research is the first to explore the use of Sc. pombe for industrial beer production.

Synergistic action of novel maltohexaose-forming amylase and branching enzyme improves the enzymatic conversion of starch to specific maltooligosaccharide

As attractive functional ingredients, maltooligosaccharides (MOS) are typically prepared by controlled enzymatic hydrolysis of starch. However, the random attack mode of amylase often leads to discrete product distribution, thereby reducing yields and purities. In this study, a novel glycoside hydrolase family 13 amylase AmyEs from marine myxobacteria Enhygromyxa salina was identified efficient maltohexaose (G6)-forming ability (40 %, w/w). By deciphering external chain length, we found that the high density of α-1,6-branching points benefits the G6 formation of AmyEs with high purity (71–82 %), indicating the substrate selectivity of AmyEs toward high-branched starch. Based on this, asynchronous conversion strategy was designed to enhance specific MOS yield from corn starch by exploiting branching enzymes and AmyEs, and the purity and yield of G6 respectively increased by 9.5 % and 5 % compared to single AmyEs treatment. Our results demonstrate that combinatorial catalysis of MOS-forming amylases and branching enzymes provides a favorable industrial preparation of specific MOS.

Exogenous γ-aminobutyric acid enhanced salt-alkaline tolerance in mulberry trees through transcriptomic sequencing analysis

Soil salinization is a widespread abiotic stress in China and one of the most critical factors affecting agricultural production and food security. γ-Aminobutyric acid (GABA) is a non-protein amino acid widely found in vertebrates, plants, and microorganisms, regulating the nervous system as well as plant defense systems. Mulberry is rich in GABA and exhibits extensive adaptability to various environments. In this study, we explored the possibility of alleviating salinity and alkalinity stress in mulberry seedlings using GABA and elucidating the intrinsic mechanisms by which GABA enhances salt-alkaline tolerance in mulberry trees through transcriptomic sequencing analysis. The results showed that 1 mM exogenous GABA enhanced the activities of mulberry seeds under saline-alkali stress, significantly increased the activities of POD and CAT (P < 0.01), reduced the level of reactive oxygen species and the content of malondialdehyde in mulberry seedlings and facilitated the growth and development of adventitious roots of mulberry. Transcriptomic analysis showed that GABA promoted the development and growth of adventitious roots of mulberry under saline-alkali stress by regulating the synthesis and modification of the cell wall, phytohormone signal transduction, and the conversion of starch and monosaccharides. Furthermore, the expression of pathogen pattern recognition receptors on the cell membrane of mulberry root system cells increased, enhancing the defense ability of mulberry root system cells. It is suggested that MYB, PME, SBT, EXP, DIR, POD, and the ARR family of transcription factors could be used as the target genes for further in-depth research.

SAAZ—Fine Aroma Hop Pedigree: A Review of Current Knowledge

The hop variety Saaz is well known over the world and is usually used for brewing of lager beers. Recently, the new related varieties Saaz Late, Brilliant, Comfort, and Shine were registered. Information about these varieties is splintered and often available only in the Czech language in regional journals. This review (i) summarizes previously published data (breeding history, genetic data, basic parameters such as yield, sensory profile, concentrations of key technologically important hop compounds), (ii) presents long-term data (2004–2021), and (iii) shows similarities/differences among these varieties. All Saaz varieties are typically fine aroma hops with a relatively low content of alpha bitter acids ranging from 5 to 7 wt%, cohumulone amounts lower than 30% rel., and hop oil content of about 1.0 wt%. Even though the new varieties have no identical chemical parameters to the original Saaz, they can substitute this established standard as well. Furthermore, the varieties Saaz Comfort and Saaz Shine show high resistance to Pseudoperonospora humuli as well as very good tolerance to drought.

Husk Separation (Kubessa Method) Impacts the Aging Chemistry of Beer.

The removal of husks before the mashing process, also known as the Kubessa method, is an established brewing practice often positively associated with smoothness and better flavor-stability of beer. Empirical evidence on the effect of the Kubessa method on beer, however, has been lacking. Similarly, our study's comprehensive analysis of established brewing attributes revealed that traditional methods do not fully capture the impact of husk separation in beer brewing. Conclusive evidence of the Kubessa method's impact on beer aging chemistry was obtained through ultrahigh resolution mass spectrometry (FT-ICR-MS), revealing intricate molecular details inaccessible to conventional analytical techniques. The compositional information on thousands of molecules in Kubessa beer was resolved and compared to whole malt mashing. Machine learning algorithms applied to aging experiments identified over 500 aging-related compounds inhibited by husk separation. Complementary Time of flight mass spectrometry (ToF-MS) coupled with chromatography further confirmed that the mashing of husks introduces sulfur-containing lipid compounds. These significant differences in the beer composition provide valuable insights for further investigation into the staling protective effect of husk-separation (Kubessa process) during beer production, as empirically demonstrated in this work.

Investigation of enzymatic conversion of various natural starches, starch‐containing products and modified starches by α‐amylase using isothermal titration calorimetry (ITC)

Investigation of enzymatic conversion of various natural starches, starch‐containing products and modified starches by α‐amylase using isothermal titration calorimetry (ITC)