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Species of Saccharomyces genus have played an irreplaceable role in alcoholic beverage and baking industry for centuries. S. cerevisiae has also become an organism of choice for industrial production of alcohol and other valuable chemicals and a model organism shaping the rise of modern genetics and genomics in the past few decades. Today´s brewing industry faces challenges of decreasing consumption of traditional beer styles and increasing consumer demand for new styles, flavors and aromas. The number of currently used brewer's strains and their genetic diversity is yet limited and implementation of more genetic and phenotypic variation is seen as a solution to cope with the market challenges. This requires modification of current production strains or introduction of novel strains from other settings, e.g. industrial or wild habitats into the brewing industry. Due to legal regulation in many countries and negative customer perception of GMO organisms, the production of food and beverages requires non-GMO production organisms, whose development can be difficult and time-consuming. Here, we apply FIND-IT (Fast Identification of Nucleotide variants by DigITal PCR), an ultrafast genome-mining method, for isolation of novel yeast variants with varying flavor profiles. The FIND-IT method uses combination of random mutagenesis, droplet digital PCR with probes that target a specific desired mutation and a sub-isolation of the mutant clone. Such an approach allows the targeted identification and isolation of specific mutant strains with eliminated production of certain flavor and off-flavors and/or changes in the strain metabolism. We demonstrate that the technology is useful for the identification of loss-of function or gain of function mutations in unrelated industrial and wild strains differing in ploidy. Where no other phenotypic selection exists, this technology serves together with standard breeding techniques as a modern tool facilitating a modification of (brewer's) yeast strains leading to diversification of the product portfolio. • Mutagenesis and ddPCR allow for targeted mutant identification in brewer's yeast. • Modification of flavor profiles has been achieved in various industrial yeasts. • Heterothallic S. eubayanus strain facilitates development of novel lager hybrids. • Combination of the method with other non-GM techniques creates phenotypic diversity. • Method enables non-GMO engineering and improvement of brewing-related properties. [ABSTRACT FROM AUTHOR]

Bottle conditioning of beer is an additional fermentation step where yeast and fermentable extract are added to the beer for carbonation. During this process, yeast must overcome environmental stresses to ensure sufficient fermentation in the bottle. Additionally, the yeast must be able to survive for a prolonged time, as a decline in viability will lead to alterations in the product. Here, we investigated the effects of bottle conditioning on beer using six different yeast strains from the brewing, wine making, and distilling industries over 120 days. The ale and lager strains resulted in a beer possessing typical characteristics of a pale ale-style beer, whereas sparkling wine and distilling yeast strains resulted in aromas that were uncharacteristic, which was expected. In addition, we observed that the various strains had different propensities to survive during bottle conditioning. Proteomic analysis was performed to ascertain protein abundance changes and reveal biological processes that potentially enabled specific yeast strains to survive longer during secondary fermentation. Our results showed that proteins associated with oxidoreductase activity and mitochondrial ribosomes were increased in the yeast strain with superior survival and were able to respond to cellular stress more effectively, whereas proteins associated with cell wall modulation were increased in the strain with poor survival characteristics. Overall, we demonstrated the impact of yeast selection on bottle conditioning and the biological processes involved in yeast physiology under these conditions. [ABSTRACT FROM AUTHOR]

To examine the variances in volatile organic compounds (VOCs) and sensory attributes across various hop cultivars, an analytical approach was employed. Specifically, gas chromatography-ion mobility spectroscopy (GC-IMS), gas chromatography-mass spectrometry (GC-MS), and quantitative descriptive analysis (QDA) were employed to scrutinize the VOCs and sensory characteristics of four distinct hop varieties, namely Magnum, Palisade, Saaz, and Hersbrucker. The outcomes of QDA revealed a diverse array of sensory profiles in the hops, encompassing citrus and non-citrus fruit aromas, woody, floral, herbal, spicy, and green aromas, with noticeable distinctions in sensory attributes discernible among the various hop cultivars. The results showed that 79 VOCs were identified in the GC-IMS spectra of different varieties of hops, including terpenes, alcohols, esters, aldehydes, and ketones. 140 VOCs were identified in the GC-MS spectra of different varieties of hops, including terpenes, alcohols, ketones, esters, acids, and aldehydes, with terpenes and esters emerging as the prevailing constituents in hops. The principal component analysis (PCA) of different hop VOCs was performed to effectively identify the differences among hop varieties. This study can provide a valuable reference for the comprehensive analysis of VOCs and sensory attributes in hops. Furthermore, it contributes theoretical underpinnings to inform the precise application of hops in the context of beer brewing. [ABSTRACT FROM AUTHOR]

The brewing industry is constantly evolving, driven by the quest for novel flavours and fermentation characteristics that cater to evolving consumer preferences. This study explores the genetic and phenotypic diversity of European farmhouse yeasts, traditionally used in rural brewing practices and maintained outside of pure culture industrial yeast selection. We isolated landrace brewing yeast strains from diverse geographical locations across Europe, including Norway, Lithuania, Latvia, and Russia, and also included African farmhouse brewing strains from Ghana. Our genomic analysis using long-read and short-read whole genome sequencing uncovered a genetically distinct group that diverges from industrial brewing yeasts. This group, which is closely related to ale brewing strains, is preliminarily named the 'European Farmhouse' group and shows greater predicted admixture from Asian fermentation strains. Through genomic and phenotypic analyses, including flavour metabolite analysis via headspace gas chromatography-mass spectrometry, sugar metabolite analysis via high-performance liquid chromatography, and wort fermentation analysis, we found a broad spectrum of fermentation capabilities, from rapid and efficient fermentation to unique aroma and flavour compound profiles, potentially offering novel traits for brewing applications. This study highlights the importance of preservation of brewing cultural heritage knowledge and resources including yeast cultures. Key points: • A large set of geographically diverse farmhouse brewing strains were characterized • Norwegian and Baltic farmhouse brewing strains form a distinct genetic group • Farmhouse strains show considerable diversity in fermentation and flavour formation [ABSTRACT FROM AUTHOR]

Red clover (Trifolium pratense) is a fodder plant grown in many regions of the world. It is also known as a medicinal plant. Red clover contains large amounts of isoflavones, which are, due to their similarity to estrogen, called phytoestrogen; it is believed that they can increase the concentration of estrogen in women. Some studies have refuted this information, but this topic is still being researched. The aim of the work was to produce beer to which red clover is added during the boiling phase and to monitor the transfer of isoflavones from red clover to beer. Red clover was not added to the control sample during boiling. During production and fermentation, the basic physical-chemical properties of wort and beer were monitored, as well as acceptability among potential consumers, which was determined by sensory analysis. The results show that phytoestrogens do end up in beer. The analyzed beer contained biochanin A, formononetin, genistein, and daidzein, in a total concentration of 12.42 µg/mL. The control sample contained none of the aforementioned compounds. Sensory analysis gave promising results, and the tested consumers all approved the taste, smell, and aroma of the produced beer. The most notable aroma that was singled out by consumers was "hay-like". [ABSTRACT FROM AUTHOR]

Over the last two decades, the craft beer industry has significantly developed with the emergence of thousands of microbreweries all over the world. These are mostly small companies that cannot afford the cost of the process monitoring systems that are usually embedded in the machinery used by industrial breweries, but they need to monitor and control the production process in order to guarantee a constant quality of beer. The development of low-cost systems for monitoring the production process would help microbreweries obtain the desired product quality consistency. In this paper, the authors propose a low-cost system for the real-time identification of the different phases of the alcoholic fermentation of beer. The first results prove the ability of the proposed system to monitor the fermentation and to detect anomalies in the process promptly. [ABSTRACT FROM AUTHOR]

This study focuses on the diversified utilization of the sugarcane industry, and sugarcane syrup, as a by-product of the sugarcane industry, is a good raw material for fermentation. Bringing sugarcane syrup into beer is conducive to the enrichment of the sugar industry, and it can improve the flavor of beer and make it more aromatic. This study determined the optimal fermentation process for beer. By analyzing the consumption rate of the carbon and nitrogen sources of raw materials, the nutrient utilization of yeast, and the causes of differences in flavor substances, the flavor composition and flavor stability of beer were determined by SPME-HS-GC-MS technology. The results showed that beer brewed with sugarcane syrup as an auxiliary raw material met the basic specifications of beer. The addition of sugarcane syrup to the wort base increased the utilization of amino acids by the yeast, and LS (lager with added cane syrup) increased the nine flavor compounds of the beer, which constituted the basic flavor of the beer, bringing new flavor compounds compared with the normal all-barley beer. Forced aging experiments showed that LS produced fewer aging compounds than OWBL. Various experiments have shown that it is feasible to ferment beer with sugarcane syrup instead of partial wort. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Discussion of the benefits of moderate alcohol consumption is ongoing. Broadly, research focusing on ethanol consumption tends to report no benefits. However, studies that distinguish between different types of alcoholic beverages, particularly beers, often reveal positive effects.The present study evaluated the genotoxic and mutagenic effects of moderate chronic consumption of India Pale Ale (IPA) craft beer. Sixty‐four adult male Swiss mice were used and divided into control and treatment groups receiving water, IPA beer with 55.23 g of ethanol per liter of beer, aqueous solution with 55.23 g of ethanol per liter, and hop infusion ad libitum for 30 days. After this period, the animals were genetically evaluated with a comet assay. For the ex vivo comet assay, blood was collected and exposed to hydrogen peroxide (H2O2). For the in vivo assay, the alkylating agent cyclophosphamide (CP) was administered to the groups after blood collection and sacrificed after 24 h. Brain, liver, and heart tissues were analyzed. Bone marrow was collected and submitted to the micronucleus test.The groups treated with IPA beer, ethanol, and hops did not show genotoxic and mutagenic action in the blood, brain, heart, or liver. The antigenotoxic action of IPA beer and hops was observed in both in vivo and ex vivo models, showing a similar reduction in DNA damage caused by CP. There was no significant difference between the groups with regard to the formation of micronuclei by CP.Moderate chronic consumption of IPA beer and hops infusion showed antigenotoxic effects in mice but no antimutagenic action. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In recent years, the demand for beers with a variety of flavors has increased considerably owing to the diversification of consumer preferences. Sour beer is characterized by a sour taste unlike normal beer flavor, and previous studies on sour beer have been primarily focused on addressing issues, such as inconsistent product quality and long production time, and on the associated microorganisms. Scientific knowledge regarding the characteristic flavor of sour beer and flavor components is limited. Therefore, in this study, we aimed to clarify the characteristic sensory attributes of sour beer and the component profiles that explain these attributes. Component analysis was performed on 10 traditional sour beers (eight Flanders Red Ales and two Lambics), using untargeted gas chromatography-mass spectrometry with liquid–liquid extraction, liquid chromatography-mass spectrometry targeting amines and anionic compounds. Further, sensory evaluation was conducted by well-trained panelists via quantitative descriptive analysis. Orthogonal partial least squares regression analysis was also conducted to investigate candidate flavor components. Thus, 261 components were identified and our methods could explain the flavor attributes of the examined samples. Comprehensive component profiling data also showed that differences in fermentation method, barrel aging duration, and blending ratio affected beer flavor. Further, Lambics were found to be characterized by citrus and phenolic aroma, while Flanders Red Ales were characterized by solvent-like aroma, sourness complexity, full bodied, graininess, astringency, and bitterness. These findings may serve as a basis for addressing issues related to sour beer production and may facilitate process design for obtaining targeted sour beer flavors. [Display omitted] [ABSTRACT FROM AUTHOR]

Sour beers play an important role in the brewing market, and their production has been growing exponentially. In light of this, six microorganisms directly related to this class of beer were studied, and the fermentation behavior of six strains used in the past for traditional commercial Berliner Weisse beer production was monitored. The microorganisms used were Lactobacillus brevis, Lactobacillus parabrevis, Brettanomyces bruxellensis, and Brettanomyces anomalus and two strains of Saccharomyces cerevisiae. The six microorganisms were selected in a previous work, and a comparison between single and mixed fermentations was carried out via daily measurements of the fermentation parameters like pH, extract, and cell count during 22 days. The ability to isolate a specific microorganism from a mixed culture was investigated using three commonly used nutrient media and aerobic/anaerobic growth conditions. Both Lactobacillus and Brettanomyces could be isolated; however, the conditions imposed were not sufficient in order to isolate Saccharomyces. Fermentations carried out with LAB and Brettanomyces showed a decrease in Lactobacillus growth if compared to pure fermentations, but no influence on the growth of Brettanomyces could be perceived. In general, fermentations carried out in the presence of Saccharomyces were dominated by this yeast. Its quick growth seems to be responsible for the high end pH values observed as well as the decrease in cell growth for both LAB and Brettanomyces. A decrease in the cell viability of Saccharomyces was followed by an increased growth of the other microorganisms involved, possibly meaning that the molecules released through apoptosis are used by both LAB and Brettanomyces as a valuable nutrient source. The volatile compound concentrations of the first group were higher in fermentations with Saccharomyces, whereas esters' concentration was higher in fermentations carried out only with Brettanomyces and Lactobacillus. Furthermore, understanding how these microorganisms interact during the fermentation process can help brewers better control production and ensure the consistency in the quality of the final product. The end pH values and acidity reached levels acceptable for Berliner Weisse beer. This innovative approach certainly contributes to the evolution and refinement of the art of brewing. [ABSTRACT FROM AUTHOR]

Arabinoxylan is a major polysaccharide found in barley and wheat. As this polysaccharide has been reported to be involved in wort viscosity and filterability, as well as β-glucan, it has become increasingly important in beer brewing in recent years, despite the limited availability of a measurement methodology for arabinoxylan. In this study, we developed a simple method for determining arabinoxylan content in wort and beer products using a commercially available xylose determination kit. The results show a relationship between arabinoxylan and the viscosity of wort and beer products. These results were consistent with previous reports, suggesting that this simple method can be used to observe the behavior of arabinoxylan during malting and brewing. [ABSTRACT FROM AUTHOR]

Lager yeasts are limited to a few strains worldwide, imposing restrictions on flavour and aroma diversity and hindering our understanding of the complex evolutionary mechanisms during yeast domestication. The recent finding of diverse S. eubayanus lineages from Patagonia offers potential for generating new lager yeasts with different flavour profiles. Here, we leverage the natural genetic diversity of S. eubayanus and expand the lager yeast repertoire by including three distinct Patagonian S. eubayanus lineages. We used experimental evolution and selection on desirable traits to enhance the fermentation profiles of novel S. cerevisiae x S. eubayanus hybrids. Our analyses reveal an intricate interplay of pre-existing diversity, selection on species-specific mitochondria, de-novo mutations, and gene copy variations in sugar metabolism genes, resulting in high ethanol production and unique aroma profiles. Hybrids with S. eubayanus mitochondria exhibited greater evolutionary potential and superior fitness post-evolution, analogous to commercial lager hybrids. Using genome-wide screens of the parental subgenomes, we identified genetic changes in IRA2, IMA1, and MALX genes that influence maltose metabolism, and increase glycolytic flux and sugar consumption in the evolved hybrids. Functional validation and transcriptome analyses confirmed increased maltose-related gene expression, influencing greater maltotriose consumption in evolved hybrids. This study demonstrates the potential for generating industrially viable lager yeast hybrids from wild Patagonian strains. Our hybridization, evolution, and mitochondrial selection approach produced hybrids with high fermentation capacity and expands lager beer brewing options. Author summary: Lager beer dominates the global market, accounting for over 90% of commercial beer varieties. The main player in lager fermentation is the yeast Saccharomyces pastorianus, an interspecific hybrid between S. cerevisiae and S. eubayanus. Despite its popularity, the range of flavours and aromas found in lager beers is restricted by the low genetic diversity of available lager strains. Here, we explored if lager yeast profiles can be diversified by leveraging natural isolates of S. eubayanus from Chilean Patagonia. We generated de novo hybrids between S. cerevisiae and three distinct S. eubayanus Patagonian lineages. Through experimental evolution and selection on fermentation traits, we improved the fermentation profiles of the hybrids. We found that mutations in IRA2, IMA1, and MALX genes enhanced their maltose and maltotriose metabolism, resulting in higher ethanol production and unique aroma profiles. Our results also confirm that S. eubayanus mitochondria confer a greater evolutionary potential than S. cerevisiae mitochondria. The current study encourages the use of wild yeast strains to develop new brewing applications to expand the repertoire of de novo lager yeasts. [ABSTRACT FROM AUTHOR]

In this study, a critical review was carried out using the Web of ScienceTM Core Collection database to analyse the scientific literature published to date to identify lines of research and future perspectives on the presence of chemical pollutants in beer brewing. Beer is one of the world's most popular drinks and the most consumed alcoholic beverage. However, a widespread challenge with potential implications for human and animal health is the presence of physical, chemical, and/or microbiological contaminants in beer. Biogenic amines, heavy metals, mycotoxins, nitrosamines, pesticides, acrylamide, phthalates, bisphenols, microplastics, and, to a lesser extent, hydrocarbons (aliphatic chlorinated and polycyclic aromatic), carbonyls, furan-derivatives, polychlorinated biphenyls, and trihalomethanes are the main chemical pollutants found during the beer brewing process. Pollution sources include raw materials, technological process steps, the brewery environment, and packaging materials. Different chemical pollutants have been found during the beer brewing process, from barley to beer. Brewing steps such as steeping, kilning, mashing, boiling, fermentation, and clarification are critical in reducing the levels of many of these pollutants. As a result, their residual levels are usually below the maximum levels allowed by international regulations. Therefore, this work was aimed at assessing how chemical pollutants appear and evolve in the brewing process, according to research developed in the last few decades. [ABSTRACT FROM AUTHOR]

The article dives into the tradition of beer brewing from the middle of the 19th century in the historical region of Háromszék, the area known today as Covasna county, Romania. From the smallest brewhouses located in villages which only fulfilled the local needs to the large factories in the towns of Sepsiszentgyörgy (Sf. Gheorghe) and Kézdivásárhely (Tg. Secuiesc) supplying even the surrounding regions, the study also sheds light on the familial relations between brewery owners, their products as well as on what remains today of the once remarkable breweries. [ABSTRACT FROM AUTHOR]

The exploration of space is becoming more feasible, and with this comes the possibility of performing fermentations in microgravity. Our study explores the potential effects of microgravity on a standard brewing model fermentation. As the fermentation of barley wort has been studied for centuries, there is an established foundation of knowledge with which to compare any changes that occur under microgravity. A modified ASBC miniature fermentation protocol (Yeast-14) was conducted within a Yuri 2.0 microgravity chamber to examine the response of Saccharomyces pastorianus to simulated microgravity conditions. Our findings reveal that yeast exhibited accelerated growth rates under microgravity compared to standard conditions. Additionally, the microgravity environment led to significantly lower levels of volatile compounds such as isoamyl acetate and 2-phenethyl acetate in the final product. Further genetic analysis showed significant downregulation of the ATF2 gene in the control group, potentially the mechanism behind the observed decrease in volatile compounds. These results show that while fermentation under microgravity is likely to eventually be commonplace, there may be changes in rate and gene expression that are beneficial or detrimental to the final product depending upon the desired characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The diversity of alcohol beverage microorganisms is of great significance for improving the brewing process and the quality of alcohol beverage products. During the process of making alcoholic beverages, a group of microorganisms, represented by yeast and lactic acid bacteria, conducts fermentation. These microorganisms have complex synergistic or competitive relationships, and the participation of different microorganisms has a major impact on the fermentation process and the flavor and aroma of the product. Strain selection is one of the key steps. Utilizing scientific breeding technology, the relationship between strains can be managed, the composition of the alcoholic beverage microbial community can be improved, and the quality and flavor of the alcoholic beverage products can be increased. Currently, research on the microbial diversity of alcohol beverages has received extensive attention. However, the selection technology for dominant bacteria in alcohol beverages has not yet been systematically summarized. To breed better-quality alcohol beverage strains and improve the quality and characteristics of wine, this paper introduces the microbial diversity characteristics of the world's three major brewing alcohols: beer, wine, and yellow wine, as well as the breeding technologies of related strains. The application of culture selection technology in the study of microbial diversity of brewed wine was reviewed and analyzed. The strain selection technology and alcohol beverage process should be combined to explore the potential application of a diverse array of alcohol beverage strains, thereby boosting the quality and flavor of the alcohol beverage and driving the sustainable development of the alcoholic beverage industry. [ABSTRACT FROM AUTHOR]

Humulus lupulus (hop) is a necessary material in beer brewing because its female inflorescences (called hop cones) give a floral aroma, bitterness and foam stability to beer. Various aspects of growth conditions in the cultivation area, especially temperature, strongly affect the yield and quality of hop cones. Recent estimates suggest that climate change accompanied by global warming is negatively impacting hop production, with high temperatures reducing the expression of genes that regulate beneficial secondary metabolites in hops. This underscores the need for techniques to enhance hop tolerance to high temperatures. This study explores the potential of N-acectylglutamic acid (NAG), a non-proteinogenic amino acid, to confer hops with tolerance against oxidative and heat stress by suppressing ROS accumulation. Exogenous NAG treatment activated the expression of HlZAT10/12 and HlHSFA2, which are putative homologues considered master regulators in response to oxidative and heat stress in Arabidopsis thaliana (Arabidopsis). Additionally, histone acetylation, a histone modification associated with transcriptional activation, was increased at these stress-responsive genes in the NAG-treated hops. These findings reveal NAG as a potential chemical compound to mitigate hop production reduction caused by high temperatures and suggest the conservation of epigenetic modification-mediated regulation of gene expression in response to environmental stresses in hops. [ABSTRACT FROM AUTHOR]

Food consumption of healthier products has become an essential trend in the food sector. This is also the case in beer, a biochemical process of transformation performed by yeast cells. More and more studies proclaim the need to reduce ethanol content in alcoholic drinks, certainly the most important health issue of beer consumption. In this review we gather key health issues related to beer consumption and the last advances regarding the use of yeast to attenuate those health problems. Furthermore, we have included the latest findings about the general positive impact of yeast in health as a consequence of its ability to biotransform polyphenolic compounds present in the wort, producing healthy compounds as hydroxytyrosol or melatonin, and its ability to perform as a probiotic driver. Besides, a group of population with chronic diseases as diabetes or celiac disease could take advantage of low carbohydrate or gluten-free beers, respectively. The role of yeast in beer production has been traditionally associated to its fermentative power. But here we have found a change in this dogma in the last years toward yeasts being a main driver to enhance healthy aspects of beer. The key findings are discussed and possible future directions are proposed. [ABSTRACT FROM AUTHOR]

This research aimed to isolate Saccharomyces cerevisiae strains from Amazonian fruits for potential utilization in beer production. Yeast strains were derived from the spontaneous fermentation of Arazá (Eugenia stipitata MacVaught), cocoa (Theobroma cacao L.), and cupuassu (Theobroma grandiflorum Wild. Ex Spreng. Schum) fruits. Identification of the isolated strains was achieved through biochemical assays and ITS rDNA (Internal Transcribed Spacer ribosomal DNA), sequencing, with emphasis on determining their affiliation to S. cerevisiae and assessing phylogenetic ties. Out of the 76 colonies isolated from the fruit fermentations, seven were distinctly identified as S. cerevisiae. Phylogenetic assessments unveiled significant parallels between regional isolates and commercial strains. Notably, beer brewed with the S. cerevisiae AR 03 isolate exhibits physical-chemical attributes characteristics similar to those found in American ale commercial beers. These findings underscore the untapped potential of leveraging Amazonian yeasts in brewing, a step forward for the region's burgeoning bioeconomy. [ABSTRACT FROM AUTHOR]

Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

Increasingly high interest in yeast–yeast interactions in mixed-culture fermentation is seen along with beer consumers' demands driving both market growth and requests for biotechnological solutions that can provide better sensory characteristics. In this study, Lachancea thermotolerans and Saccharomyces cerevisiae with a cell population ratio of 10:1 were inoculated for sour beer fermentation while the process conditions within the brewing industry remained unchanged. With L. thermotolerans producing lactic acid (1.5–1.8 g/L) and bringing down the pH to 3.3–3.4 whilst adding no foreign flavors herein, this study revealed a new natural, fruity sour beer with a soft, sour taste. In this study, the double-yeast mixed-culture fermentation produced more flavor substances than a single-culture process, and plenty of isobutyl acetate and isoamyl acetate enhanced the fruit aroma and balanced the sour beer with a refreshing taste. While playing a positive role in improving the beer's quality, the double-yeast mixed-culture fermentation developed in this study helps to offer an alternative mass production solution for producing sour beer with the processes better controlled and the fermentation time reduced. The stress responses of the L. thermotolerans during the fermentation were revealed by integrating RNA sequencing (RNA-Seq) and metabolite data. Given that the metabolic flux distribution of the S. cerevisiae during the fermentation differed from that of the non-Saccharomyces yeasts, transcriptional analysis of non-Saccharomyces yeast and S. cerevisiae could be suitable in helping to develop strategies to modulate the transcriptional responses of specific genes that are associated with the aroma compounds released by S. cerevisiae and non-Saccharomyces yeasts. In the case of some non-Saccharomyces yeast species/strains, the diversion of alcoholic fermentation and the formation of a great number of secondary compounds may, in part, account for the low ethanol yield. [ABSTRACT FROM AUTHOR]

Copyright of Zywnosc is the property of Polish Society of Food Technologists - Scientific Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

"Sake Yeast Beer" is a beer style characterized by the unique flavor of the sake yeast strain; however, it cannot ferment wort because of the low assimilation ability of maltose. Herein, a sake yeast strain was bred for improved maltose assimilation ability and an original sake yeast strain optimized for a beer brewing environment was developed. The mutant sake yeast strains produced large amounts of isoamyl acetate (3-methylbutyl acetate) and ethyl caproate (ethyl hexanoate) responsible for the ginjo-aroma of sake. A detailed analysis of the volatile components in a small-scale beer brewing test revealed that the beer brewed with BMK3, one of the mutant strains, was composed of many volatile components generated by yeast, such as esters, alcohols, and fatty acids, in comparison to the beer fermented with a general brewer's yeast. Moreover, in a full-scale beer brewing test using BMK3, the beer was composed of isoamyl acetate and ethyl caproate at 2.3 and 6.7 ppm, respectively. On the sensory evaluation of two beers fermented with BMK3 and a general brewer's yeast, the beer brewed with BMK3 had the unique characteristics of "ginjo-aroma like fruit," remaining "sweetness," and a "rich body but crisp finish." [ABSTRACT FROM AUTHOR]

Preliminary research was conducted on the analytical and flavor profiles of beers brewed (small-scale) with roasted specialty malts and raw malts as adjuncts. Beers were characterized by physico-chemical, sensory, and GC-MS analysis. From the beers produced, 79 volatile compounds were identified, and these were grouped into different categories. Alcohols and esters were found to be the most prevalent volatile compounds in the beers. Principal component analysis, as well as cluster analysis, was applied in order to investigate the similarities and distinctions between the various types of adjuncts and no adjunct beers. The volatile chemicals present in the beers showed that the nature and quantity of these compounds would have an effect on the flavor and quality of the beers. Beers prepared with the roasted wheat malt addition were characterized by the highest number of volatile compounds. Moreover, the beers with roasted wheat malt addition were characterized by higher bitterness (higher than the control beer), high antioxidant activity (equal to the control beer), and a high tannin content (but less than the control beer). Beers were evaluated by a sensory panel that concluded that the adjunct beers had a preferred flavor to the beers without adjunct addition. The highest-rated beer in the appearance, flavor, mouthfeel, and overall acceptability criteria was the adjunct beer with roasted wheat malt incorporated. This preliminary experimentation will help guide where future research is needed and where scale-up experiments with trained taste panels should focus. [ABSTRACT FROM AUTHOR]

South African National Senior Certificate examination reports consistently reflect poor performance in STEM (science, technology, engineering, and mathematics) subjects when compared to other subjects. This has resulted in a decline in the uptake of STEM subjects because many students perceive them as being difficult to learn. This phenomenon is not unique to South Africa, as many other African and developed countries are facing similar difficulties in terms of student participation in STEM subjects. Reasons for the low uptake of STEM subjects include perceived difficulty, perceived lack of ability, classroom experience of STEM subjects, and lack of enjoyment. Thus, STEM educators across the globe are confronted with the challenge of making the subjects attractive, accessible to, and relevant for students. Humanising the teaching of STEM subjects by building on Indigenous knowledges has been suggested as a way that secondary education could deal with these challenges, and turn them into STEM capabilities. The incorporation of Indigenous and other local knowledges into STEM subjects could promote authentic learning experiences, relevance, and inclusivity if teachers were prepared for this, and appropriate resources made available. In Africa, many children enrol in school while they are concurrently engaged in subsistence economic activities rooted in Indigenous practices. Leveraging the insights gained from these activities could humanise and enhance the relevance of school STEM curricula. Karanga beer brewing is one such activity that we participated in as children and, in this paper, we report our exploration of the science related to Karanga beer brewing and how it can be a way of humanising and promoting the relevance of school science and other STEM subjects. [ABSTRACT FROM AUTHOR]

Traditional fermented beverages are culturally and socially accepted products for consumption, drinking, entertainment, customary practices, and for religious purposes. The purpose of this review was to identify some cereal-based fermented beverages and determine the differences in their production technologies. There are many unique regional variations in the preparation of each of the identified fermented beverages. They are prepared from raw materials such as maize, millet, rice, and sorghum. Majority of the fermented alcoholic beverages (binuburan, amba beer, sake, dolo, pito, and tchoukoutou) were produced using spontaneous fermentation and industrial fermentation (use of starter cultures) techniques. The various microbial communities associated with the traditional fermentation processes were dominated by Limosilactobacillus fermentum and Lactiplantibacillus plantarum for Lactic acid bacterial (LAB) species, Saccharomyces cerevisiae and Candida mycoderma for Saccharomyces and Candida species (yeasts), respectively; and Aspergillus aceti and Rhizopus stolonifer for Aspergillus and Rhizopus species (molds), respectively. Acetobacter, Pseudomonas, Klebsiella, Weissella, Achromobacter, Flavobacterium, Micrococcus, and Bacillus dominated other microbial genera. The involvement of lactic acid bacteria contributed to the safety and extension of the shelf life of the final products. Most of these beverages were found to be very rich in proteins, carbohydrates, calories, and B-group vitamins including thiamine, folic acid, riboflavin, and nicotinic acid. This article reviewed the available information, such as processing techniques of African traditional beverages, the raw materials used to producing them, and the microorganisms associated with the production processes. [ABSTRACT FROM AUTHOR]

Background: Beer is the most consumed alcoholic beverage globally, and the demand for differentiated beers with peculiar characteristics has intensified among beer consumers, creating a significant market niche. In this study, we developed a low alcohol light craft beer enriched with olive leaf extract (Olea europaea L.). The cold mashing technique associated with interrupted fermentation was used in the mashing step. Different concentrations of olive leaf extract (0.5, 1.0 and 2.0%) were added at the maturation stage. The samples were characterized by physicochemical parameters, phenolic and polyphenolic content, bioactive compounds, antioxidant potential, and microbiological quality. Results: The cold mash technique associated with interrupted fermentation provided a low-alcohol beer (≅1.3%). The bitterness dimension (19.0 to 23.2 IBU) and color (9–17 EBC) parameter were in accordance with the Beer Judge Certification Program (BJCP) for the American Blond Ale-style. The addition of the extract enriched the content of total phenolics (171.09 to 437.4 mg GAE/mL) and polyphenolic (221.4 to 729.0 mg/L). Coumaric, ferulic, and cinnamic phenolic acids were detected in appreciable amounts in the beers. Oleuropein was the major compound in the beverage and plant extract. After adding 2% extract, the ABTS and DPPH radical scavenging activity, as well as the ferric reduction power, increased in beers by 28.4%, 449.1%, and 120.5%, respectively. Conclusions: The extract of O. europaea L. promoted the enrichment of low-alcohol beer samples with bioactive compounds and antioxidant potential. The results obtained indicated the potential use of O. europaea L. extract as a natural oxidant in other beverages and food products. [ABSTRACT FROM AUTHOR]

Studying the genetic and molecular characteristics of brewing yeast strains is crucial for understanding their domestication history and adaptations accumulated over time in fermentation environments, and for guiding optimizations to the brewing process itself. Saccharomyces cerevisiae (brewing yeast) is among the most profiled organisms on the planet, yet the temporal molecular changes that underlie industrial fermentation and beer brewing remain understudied. Here, we characterized the genomic makeup of a Saccharomyces cerevisiae ale yeast widely used in the production of Hefeweizen beers, and applied shotgun mass spectrometry to systematically measure the proteomic changes throughout 2 fermentation cycles which were separated by 14 rounds of serial repitching. The resulting brewing yeast proteomics resource includes 64,740 protein abundance measurements. We found that this strain possesses typical genetic characteristics of Saccharomyces cerevisiae ale strains and displayed progressive shifts in molecular processes during fermentation based on protein abundance changes. We observed protein abundance differences between early fermentation batches compared to those separated by 14 rounds of serial repitching. The observed abundance differences occurred mainly in proteins involved in the metabolism of ergosterol and isobutyraldehyde. Our systematic profiling serves as a starting point for deeper characterization of how the yeast proteome changes during commercial fermentations and additionally serves as a resource to guide fermentation protocols, strain handling, and engineering practices in commercial brewing and fermentation environments. Finally, we created a web interface (https://brewing-yeast-proteomics.ccbb.utexas.edu/) to serve as a valuable resource for yeast geneticists, brewers, and biochemists to provide insights into the global trends underlying commercial beer production. [ABSTRACT FROM AUTHOR]

The ascendency of the craft beer movement within the brewing industry may be attributed to its commitment to unique flavours and innovative styles. Mixed-culture fermentation, celebrated for its novel organoleptic profiles, presents a modelling challenge due to its complex microbial dynamics. This study addresses the inherent complexity of modelling mixed-culture beer fermentation while acknowledging the condition monitoring limitations of craft breweries, namely sporadic offline sampling rates and limited available measurement parameters. A data-driven solution is proposed, utilising an Autoregressive Recurrent Neural Network (AR-RNN) to facilitate the production of novel, replicable, mixed-culture fermented beers. This research identifies time from pitch, specific gravity, pH, and fluid temperature as pivotal model parameters that are cost-effective for craft breweries to monitor offline. Notably, the autoregressive RNN fermentation model is generated using high-frequency multivariate data, a departure from intermittent offline measurements. Employing the trained autoregressive RNN framework, we demonstrate its robust forecasting prowess using limited offline input data, emphasising its ability to capture intricate fermentation dynamics. This data-driven approach offers significant advantages, showcasing the model's accuracy across various fermentation configurations. Moreover, tailoring the design to the craft beer market's unique demands significantly enhances the model's practicable predictive capabilities. It empowers nuanced decision-making in real-world mixed-culture beer production. Furthermore, this model lays the groundwork for future studies, highlighting transformative possibilities for cost-effective model-based control systems in the craft beer sector. [ABSTRACT FROM AUTHOR]

Prodigiosin (PG)—a molecule with promising applications in many fields—was effectively biosynthesized in this study using a novel and eco-friendly fermentation substrate—i.e., beer brewing by-product (BBB). It was confirmed as a nutrient-rich substrate source of protein (22.18%), ash (10.1%), carbohydrate (1.98%), sugar, and abundant mineral elements. The cultural medium with a newly designed formula on a small flask containing 1.25% BBB/Casein (9/1), 0.025% FeSO4, and 0.125% Na2HPO4 for a notable PG yield achieved 6230 mg/L after 48 h. PG production on a bioreactor system also enhanced yield by 1.16 folds (reaching 7220 mg/L) and shortened fermentation time (only taking 10 h). This pure pigment was isolated and identified by analyzing UV/vis absorption, MALDI-TOF MS, and HPLC. The obtained PG was used for antifungal tests. Notably, in this work, most of PG's pathogen fungal inhibition activity are new findings. Of those, PG showed the most positive effect on Colletotrichum gloeosporioides F05 strain (causing on sweet potato roots) with inhibition rates of mycelial growth and spore germination achieved at 47 and 57%, respectively. In particular, PG also reduced resistance and wholly inhibited mycelium growth germinating from spores. Furthermore, PG showed the good interaction ability with multiple target proteins (CDC42, CYP51, CAS2, Pectate lyase B, and Beta tubulin) inhibiting C. gloeosporioides via docking simulation. The results of this study revealed useful scientific information related to the novel application of BBB in PG production and the new PG's effects in the management of fungal pathogens in crops. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ethanol and osmotic stresses are the major limiting factors for brewing strong beer with high‐gravity wort. Breeding of yeast strains with high osmotic and ethanol tolerance and studying very‐high‐gravity (VHG) brewing technology is of great significance for brewing strong beer. RESULTS: This study used an optimized microbial microdroplet culture (MMC) system for adaptive laboratory evolution (ALE) of Saccharomyces cerevisiae YN81 to improve its tolerance to osmotic and ethanol stress. Meanwhile, we investigated the VHG and VHG with added ethanol (VHGAE) brewing processes for the evolved mutants in brewing strong beer. The results showed that three evolved mutants were obtained; among them, the growth performance of YN81mc‐8.3 under 300, 340, 380, 420 and 460 g L−1 sucrose stresses was greater than that of the other strains. The ethanol tolerance of YN81mc‐8.3 was 12%, which was 20% higher than that of YN81. During strong‐beer brewing in a 100 L cylindrical cone‐bottom tank, the sugar utilization and ethanol yield of YN81mc‐8.3 outperformed those of YN81 in both the VHG and VHGAE brewing processes. Measurement of the diacetyl concentration showed that YN81mc‐8.3 had a stronger diacetyl reduction ability; in particular, the real degree of fermentation of beers brewed by YN81mc‐8.3 in VHG and VHGAE brewing processes was 75.35% and 66.71%, respectively – higher than those of the two samples brewed by YN81. Meanwhile, the visual, olfactive and gustative properties of the strong beer produced by YN81mc‐8.3 were better than those of the other beers. CONCLUSION: In this study, the mutant YN81mc‐8.3 and the VHGAE brewing process were optimal and represented a better alternative strong‐beer brewing process. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

It has become apparent that beer (both alcoholic and nonalcoholic) contains appreciable amounts of non-starch polysaccharides, a broad subgroup of dietary fiber. It is worth noting that the occurrence of non-starch polysaccharides in alcoholic beer does not imply this should be consumed as a source of nutrition. But the popularity of nonalcoholic beer is growing, and the lessons learnt from non-starch polysaccharides in brewing can be largely translated to nonalcoholic beer. For context, we briefly review the origins of dietary fiber, its importance within the human diet and the significance of water-soluble dietary fiber in beverages. We review the relationship between non-starch polysaccharides and brewing, giving focus to the techniques used to quantify non-starch polysaccharides in beer, how they affect the physicochemical properties of beer and their influence on the brewing process. The content of non-starch polysaccharides in both regular and low/nonalcoholic beer ranges between 0.5 − 4.0 g/L and are predominantly composed of arabinoxylans and β-glucans. The process of malting, wort production and filtration significantly affect the soluble non-starch polysaccharide content in the final beer. Beer viscosity and turbidity are strongly associated with the content of non-starch polysaccharides. [ABSTRACT FROM AUTHOR]

Beer is made via the fermentation of an aqueous extract predominantly composed of malted barley flavoured with hops. The transforming microorganism is typically a single strain of Saccharomyces cerevisiae, and for the majority of major beer brands the yeast strain is a unique component. The present yeast used to make Guinness stout brewed in Dublin, Ireland, can be traced back to 1903, but its origins are unknown. To that end, we used Illumina and Nanopore sequencing to generate whole-genome sequencing data for a total of 22 S. cerevisiae yeast strains: 16 from the Guinness collection and 6 other historical Irish brewing. The origins of the Guinness yeast were determined with a SNP-based analysis, demonstrating that the Guinness strains occupy a distinct group separate from other historical Irish brewing yeasts. Assessment of chromosome number, copy number variation and phenotypic evaluation of key brewing attributes established Guinness yeast-specific SNPs but no specific chromosomal amplifications. Our analysis also demonstrated the effects of yeast storage on phylogeny. Altogether, our results suggest that the Guinness yeast used today is related to the first deposited Guinness yeast; the 1903 Watling Laboratory Guinness yeast. A genomic analysis of 22 S. cereviseae yeast strains used in beer brewing suggest that yeast used to brew Guinness form a distinct evolutionary sub-clade, and that the modern-day Guinness yeast is closely related to the 1903 Watling Laboratory Guinness yeast. [ABSTRACT FROM AUTHOR]

Most of the yeast species we encounter daily are terrestrial, but they are also found in the marine environment. Marine yeasts occur in estuaries, coastal and open marine waters, sediments, and as epi- and endobionts of various marine organisms. This study focuses on the fermentation capabilities of marine yeasts isolated from the central Adriatic Sea for use in the brewing process. Sampling was performed at a sea temperature of 12°C to avoid collecting yeasts introduced into the marine environment by human activities. Four nutrient media designed for yeast isolation and growth were used to isolate yeasts from the marine samples: Yeast Malt Agar (YM), Yeast Malt Agar with antibiotics, acidified Yeast Malt Agar, and Sabouraud Dextrose Agar. Sixteen yeast colonies were successfully isolated, and only three were positive in the fermentation test and were further determined to species level. Of the three species identified as capable of fermentation, Candida famata completely fermented the wort and produced a beer. Candida pelliculosa fermented slowly over an extended period and did not produce a usable beer, while Candida sake did not ferment the wort at all. To our knowledge, this is the first time that marine yeast isolates have been used experimentally for beer fermentation, indicating potential for use as nonconventional yeasts in brewing and beer production. Further investigations should include professional standard fermentation, aroma and genetic studies. [ABSTRACT FROM AUTHOR]

Høiby N. Louis Pasteur and the birth of microbiology in Denmark. APMIS 2022. Louis Pasteur's work initiated the birth of microbiology in Denmark. Carl Julius Salomonsen was the pioneer who inspired and taught Christian Gram, Thorvald Madsen and Bernhard Bang bacteriological techniques in his annual bacteriological course which he started in 1883 at the University of Copenhagen. These pioneers developed Danish human and veterinary microbiology and became world famous. Emil Chr. Hansen developed Danish technical/industrial microbiology in the Carlsberg Laboratory and purified yeast and designed equipment for the propagation of pure yeast which was used worldwide in beer brewing. He also became world famous. The fascinating birth and development of Danish microbiology is summarized in this article, which is dedicated to the 200th birthday of Louis Pasteur, December 27, and 100th birthday of the Danish Pasteur Society, October 25, 2022. [ABSTRACT FROM AUTHOR]

The purpose of this paper is the sensory and physico-chemical characterization of craft ginger beer obtained under laboratory conditions. For this paper we prepared blonde beer (Indian Pale Ale - IPA) with ginger, the Ginger Beer assortment through the one-stage brewing method, in an amount of approximately 2 liters. The preparation resulted in a craft ginger beer with some insignificant defects (insufficient foaming, slightly high relative density, high acidity), defects explained by the too high temperature during primary fermentation and the continuation of secondary fermentation in bottles. On the other hand, the craft beer obtained has well-defined sensory qualities and is appreciated by the tasters (appearance, smell and taste), as well as a high alcoholic concentration, which qualitatively distinguishes it, compared to other commercial beers. Once these deficiencies are identified and rectified, the craft beer recipe experimented in the laboratory can be successfully replicated in any microenterprise, which has as its profile the production of craft beer and opens the way for experimentation and innovation of other recipes. [ABSTRACT FROM AUTHOR]

Sustainable beer production requires a comprehensive assessment of potential hazards such as pesticides in both the finished product and waste streams, as these streams can be used to create high-value by-products. This study presents the tracking of 13 fungicides (azoxystrobin, boscalid, epoxiconazole, fenpropidin, fenpropimorph, fluquiconazole, flutriafol, fluxapyroxad, kresoxym-methyl, spiroxamine, propiconazole, prothioconazole-desthio, and tebuconazole), two insecticides (chlorpyrifos-methyl and deltamethrin), one herbicide (glyphosate), and one growth regulator (mepiquat) through the beer brewing process. Field-treated rye, wheat, and barley samples containing pesticide residues were used as adjunct during brewing. Samples of the beer as well as the by-products (spent grain, spent hops, trub and spent yeast) were collected and extracted with a modified QuEChERS method for pesticide residues analysis using GC-MS/MS and LC-MS/MS. Results show that an average of 58% of pesticide residues are retrieved in the by-products with the highest fraction (53%) recovered in the spent grain, 4% in trub, 1% in spent hops, no residues detected in spent yeast and 9% in the beer. This is consistent with these nonpolar pesticides tending to remain adsorbed to the spent grain during brewing. Glyphosate and mepiquat, the most polar pesticides included in this study, showed a different behavior, with the largest fraction (>80%) being retrieved in sweet wort and transferred to the beer. Processing factors were generated for each pesticide from the adjunct to the beer and to the four by-products. [ABSTRACT FROM AUTHOR]

Belgian Saisons and Lambics are two well‐known examples in the brewing industry of mixed fermentations, combination of two or more yeast and/or bacteria strains. The purpose of this study was to determine the impact different pitch rates of Saccharomyces cerevisiae (traditional brewing yeast) and S. cerevisiae var. diastaticus (a variant associated with Belgian styles) had on the fermentation kinetics and concentration of the volatile compounds in the finished beers. A series of brews were performed utilizing ratios of S. cerevisiae and diastaticus. The fermentations were heavily monitored, and a model was used to fit fermentation variables. It was found that mixed fermentations produced behaviors that were predictable and proportional to the mixture ratios. As expected, the pure cultural fermentations of diastaticus had a slower fermentation midpoint (M) at 45.45 h versus 28.28 h for S. cerevisiae with the mixed ones falling in between the two. Flavor and aroma play a key role in the acceptability of beer. The mixed fermentations showed a combination of the two different yeast strains aromatic profiles. When combined, there was a strong linearity between alcohols (R2 = 0.94), esters (R2 = 0.89), and the overall total (R2 = 0.91) volatile compounds. Practical Application: Modeling is a widely utilized tool in several different fields. The purpose of this research is to apply modeling techniques to describe the fermentation speed and flavor profile of a mixed fermentation between S. cerevisiae and diastaticus. The equations from this data can be used by brewers for product development purposes to make beers with certain flavor profiles within a desired timeframe. [ABSTRACT FROM AUTHOR]

Chromosome aneuploidy is a common phenomenon in industrial yeast. Aneuploidy is considered one of the strategies to enhance the industrial properties of Saccharomyces cerevisiae strains. However, the effects of chromosomal aneuploidy on the brewing properties of sake have not been extensively studied. In this study, sake brewing was performed using a series of genome-wide segmental duplicated laboratory S. cerevisiae strains, and the effects of each segmentally duplicated region on sake brewing were investigated. We found that the duplication of specific chromosomal regions affected the production of organic acids and aromatic compounds in sake brewing. As organic acids significantly influence the taste of sake, we focused on the segmental duplication of chromosome II that alters malate levels. Sake yeast Kyokai No. 901 strains with segmental chromosome II duplication were constructed using a polymerase chain reaction-mediated chromosomal duplication method, and sake was brewed using the resultant aneuploid sake yeast strains. The results showed the possibility of developing sake yeast strains exhibiting low malate production without affecting ethanol production capacity. Our study revealed that aneuploidy in yeast alters the brewing properties; in particular, the aneuploidy of chromosome II alters malate production in sake brewing. In conclusion, aneuploidization can be a novel and useful tool to breed sake yeast strains with improved traits, possessing industrial significance. [ABSTRACT FROM AUTHOR]

Different malt samples with various total acid content were used to brew beer. The organic acid content in both the malt and the brewed beer was measured by using high-Performance liquid chromatography (HPLC) to establish the correlation between the total acid content in malt and the organic acid content in the beer. Additionally, gas chromatography-mass spectrometry (GC-MS) was used to detect the components of volatile compounds in the beer, and sensory evaluation was employed to assess the brewed beer's qualities. The results indicated that as the total acid content in malt increased, the pH value gradually decreased, and the content of succinic acid, malic acid, lactic acid, and acetic acid increased. There was a significant positive correlation between the total acid content in malt and the total acid content, malic acid content, and lactic acid content in the beer, with correlation coefficients of 0.94, 0.94, and 0.92, respectively. Different malt samples with varying total acid content demonstrated different characteristic aroma compounds in the brewed beer, contributing to differences in sensory attributes. As the total acid content in malt increased, the perceived acidity score of the brewed beer increased, while the scores for hop/fruit aroma, phenolic aroma, and alcohol perception decreased. [ABSTRACT FROM AUTHOR]