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Algumas características relacionadas à qualidade do malte podem ser trabalhadas não só ao nível genético e/ou como respostas de interações ambientais, mas também ao nível de processo industrial. O objetivo do presente trabalho foi avaliar o efeito da temperatura sobre a atividade das β-glucanases e degradacão de β-glucanos durante os quatro dias finais de germinação do processo de malteação. Quatro cultivares de boa qualidade de malteação ('N721', 'N743', 'Scarlett' e 'Sebastian') foram analisadas e os resultados obtidos demonstraram que elas tiveram desempenho diferente quanto à atividade enzimática e à degradação de β-glucanos nas diferentes temperaturas testadas. A utilização de temperatura um pouco mais elevada no início da germinação (22°C) foi a mais efetiva na produção das variáveis estudadas. Para a cultivar 'N721', constatou-se o melhor desempenho comparativamente às demais, indicando um padrão mais homogêneo de degradação de β-glucanos durante a germinação e também maior eficiência na degradação desde as 96 horas do processo. Alta atividade das β-glucanases e redução no tempo de malteação são de extremo interesse para a indústria malteira, pois representa uma otimização no volume de malte produzido e consequentemente uma redução de custos para a sua produção. Some characteristics related to the quality of malt can be worked not only at the genetic level and/or as responses to environmental interactions, but also in industrial process. This study assesses the effect of temperature on β-glucanase activity and on the degradation of β-glucans during the last four days of germination, in the malting process. Four cultivars of good quality malting ('N721', 'N743', 'Scarlett' and 'Sebastian') were analyzed and the results showed they had different performance on the enzyme activity and β-glucan degradation, at the different temperatures tested. A slightly higher temperature at the beginning of germination (22°C) was more effective in terms of the variables studied. Cultivar 'N721' presented the best performance compared to other cultivars, revealing a more homogeneous pattern of β-glucan degradation during germination and also increased efficiency in degrading -glucans as early as in the 96th hour of the germination process. High activity of β-glucanases and shorter time is very interesting to the brewery industry, since it represents an optimization of the malt volume produced and a cost reduction for its production.

In field trials with four spring barley cultivars (Astor, Fran, Matej and Scarlett) during four years (2004-2007) at two localities (Osijek and Nova Gradiska) researches of grain yield, hectoliter weight, protein and starch content, extract content, friability of malt, Kolbach index and malt viscosity were carried out. Cultivar Matej (5.535 t ha-1) had significantly higher (P>0.05) grain yield in comparison with cultivars Astor 4.968 t ha-1), Fran (5.113 t ha-1) and Scarlett (5.150 t ha- 1). The year of production had significant influence on grain yield as well as on all indicators of malt quality, and differences in grain yield between localities Osijek and Nova Gradiska were not statistically justified. Significant differences between localities Osijek and Nova Gradiska in extract content and friability were estimated. Based on extract content and parameters of malt modification the best scores had cultivar Scarlett which was followed by cultivar Fran. Cultivar Scarlett had grain yield at average level of the trial, but high interaction scores (IPCA1) indicated the high adaptability of this genotype to conditions of production.

Malted barley (malt) is traditionally used in the production of beer and distilled spirits. In addition, it can be processed into ingredients for different areas of the food industry. Malting, the controlled germination of cereal grains, is a complex biological process involving a wide range of biochemical and physiological reactions. The diverse microbial communities naturally colonizing barley grains play a crucial role in this process. Therefore, the malting process can be considered as an ecosystem involving two metabolically active groups: the germinating grains and the diverse microbiota. It is evident that the multitude of microbes greatly influences the malting process as well as the quality of the final product. The main goal of this thesis was to study the relationships between microbes and the germinating grain during the malting process. Furthemore, this study provides a basis for tailoring of malt properties with natural, malt-derived microbes. The results of this study showed that the malting ecosystem is indeed a dynamic process and exhibits continuous change. Microbes embedded in biofilms within the husk tissues were well protected. Reduction of one population within the complex ecosystem led to an increase in competing microbes. This should be taken into account when changes are made in the malting process. Using different molecular approaches we also found that the diversity of microbes in malting was much greater than previously anticipated. Some potentially novel bacterial and fungal species were found in the malting ecosystem. The microbial communities greatly influenced grain germination and malt properties. By suppressing Gram-negative bacteria during steeping, barley vitality and malt brewhouse performance were improved even in the case of good-quality malting barley. The fungal community consisting of both yeasts and filamentous fungi significantly contributed to the production of microbial glucanases and xylanases, and was also involved in the proteolysis. Previously the significance of yeasts in the malting ecosystem has been largely underestimated. This study showed that a numerous and diverse yeast community consisting of both ascomycetous (25) and basidiomycetous (18) species occured in the industrial malting ecosystem. Yeast and yeast-like fungi produced extracellular hydrolytic enzymes with a potentially positive contribution to malt processability. Furthermore, several yeast strains showed strong antagonistic activity against field and storage moulds. The management of microbes in the whole barley-malt-beer chain is extremely important with respect to both process and product safety and quality. Lactic acid bacteria (LAB) can be used to tailor the malt properties. Lactobacillus plantarum VTT E-78076 (E76) and Pediococcus pentosaceus VTT E-90390 (E390) added to steeping water promoted yeast growth and restricted the growth of Gram-negative bacteria and Fusarium fungi. Furthermore, they had positive effects on malt characteristics and notably improved wort separation. Some of the beneficial effects observed with LAB were due to the lactic acid production and concomitant lowering of pH. Futhermore, increase in the number of yeasts could partly explain the enhanced xylanase and -glucanase levels observed after LAB addition. Addition of a specific yeast culture (Pichia anomala VTT C-04565) into the steeping water of barley restricted Fusarium growth and hydrophobin production during malting and thus prevented beer gushing. This study also revealed that P. anomala retarded the wort filtration, but that the filtration performance was recovered when yeast cultures were combined with L. plantarum E76. The combination of different microbial cultures offers a possibility to utilise their different properties, thus making the system more robust. Improved understanding of the complex microbial communities in the malting ecosystem will enable more efficient control of unwanted microbiological phenomena as well as utilization of the beneficial properties of microbes in malt production.

Malted barley (malt) is traditionally used in the production of beer and distilled spirits. In addition, it can be processed into ingredients for different areas of the food industry. Malting, the controlled germination of cereal grains, is a complex biological process involving a wide range of biochemical and physiological reactions. The diverse microbial communities naturally colonizing barley grains play a crucial role in this process. Therefore, the malting process can be considered as an ecosystem involving two metabolically active groups: the germinating grains and the diverse microbiota. It is evident that the multitude of microbes greatly influences the malting process as well as the quality of the final product. The main goal of this thesis was to study the relationships between microbes and the germinating grain during the malting process. Furthemore, this study provides a basis for tailoring of malt properties with natural, malt-derived microbes. The results of this study showed that the malting ecosystem is indeed a dynamic process and exhibits continuous change. Microbes embedded in biofilms within the husk tissues were well protected. Reduction of one population within the complex ecosystem led to an increase in competing microbes. This should be taken into account when changes are made in the malting process. Using different molecular approaches we also found that the diversity of microbes in malting was much greater than previously anticipated. Some potentially novel bacterial and fungal species were found in the malting ecosystem. The microbial communities greatly influenced grain germination and malt properties. By suppressing Gram-negative bacteria during steeping, barley vitality and malt brewhouse performance were improved even in the case of good-quality malting barley. The fungal community consisting of both yeasts and filamentous fungi significantly contributed to the production of microbial glucanases and xylanases, and was also involved in the proteolysis. Previously the significance of yeasts in the malting ecosystem has been largely underestimated. This study showed that a numerous and diverse yeast community consisting of both ascomycetous (25) and basidiomycetous (18) species occured in the industrial malting ecosystem. Yeast and yeast-like fungi produced extracellular hydrolytic enzymes with a potentially positive contribution to malt processability. Furthermore, several yeast strains showed strong antagonistic activity against field and storage moulds. The management of microbes in the whole barley-malt-beer chain is extremely important with respect to both process and product safety and quality. Lactic acid bacteria (LAB) can be used to tailor the malt properties. Lactobacillus plantarum VTT E-78076 (E76) and Pediococcus pentosaceus VTT E-90390 (E390) added to steeping water promoted yeast growth and restricted the growth of Gram-negative bacteria and Fusarium fungi. Furthermore, they had positive effects on malt characteristics and notably improved wort separation. Some of the beneficial effects observed with LAB were due to the lactic acid production and concomitant lowering of pH. Futhermore, increase in the number of yeasts could partly explain the enhanced xylanase and -glucanase levels observed after LAB addition. Addition of a specific yeast culture (Pichia anomala VTT C-04565) into the steeping water of barley restricted Fusarium growth and hydrophobin production during malting and thus prevented beer gushing. This study also revealed that P. anomala retarded the wort filtration, but that the filtration performance was recovered when yeast cultures were combined with L. plantarum E76. The combination of different microbial cultures offers a possibility to utilise their different properties, thus making the system more robust. Improved understanding of the complex microbial communities in the malting ecosystem will enable more efficient control of unwanted microbiological phenomena as well as utilization of the beneficial properties of microbes in malt production.

Conducted researches showed significant effect of cultivar and environment on grain yield and malting quality of barley. Barun is cultivar with the highest grain yield and very good indicators of protein and malt extract content. Vanessa had lower grain yield than cultivars Barun and Zlatko, higher protein content in grain but the best indicators of malt extract, malt viscosity and beta-glucan. Cluster analysis of malt extract content indicated grouping of locations Nova Gradiska and Pozega as well as Osijek and Tovarnik, which did not depend on year. Significant differences were found for beta glucan content between years and locations of testing, and particularly inadequate beta glucan content was found at Osijek and Nova Gradiska locations in 2005. Interactions of variety and environment may have an impact on sustainable cropping methods.

Barley grain carries a numerous, variable, and complex microbial population that mainly consists of bacteria, yeasts, and filamentous fungi and that can partly be detected and quantified using plating methods and microscopic and molecular techniques. The extent and the activity of this microflora are determined by the altering state of the grain and the environmental conditions in the malt production chain. Three ecological systems can be distinguished: the growing cereal in the field, the dry barley grain under storage, and the germinating barley kernel during actual malting. Microorganisms interact with the malting process both by their presence and by their metabolic activity. In this respect, interference with the oxygen uptake by the barley grain and secretion of enzymes, hormones, toxins, and acids that may affect the plant physiological processes have been studied. As a result of the interaction, microorganisms can cause important losses and influence malt quality as measured by brewhouse performance and beer quality. Of particular concern is the occurrence of mycotoxins that may affect the safety of malt. The development of the microflora during malt production can to a certain extent be controlled by the selection of appropriate process conditions. Physical and chemical treatments to inactivate the microbial population on the barley grain are suggested. Recent developments, however, aim to control the microbial activity during malt production by promoting the growth of desirable microbial cultures, selected either as biocontrol agents inhibiting mycotoxin-producing molds or as starter cultures actively contributing to malt modification. Such techniques may offer natural opportunities to improve the quality and safety of malt. ispartof: Critical reviews in microbiology vol:25 issue:2 pages:121-153 ispartof: location:England status: published

Kultivar Viktor (priznat 1996. god.) ozimog dvorednog ječma u ispitivanjima Sortne komisije, Ministarstva za poljoprivredu i šumarstvo Republike Hrvatske bio je višeg uroda zrna, ujednačenijeg zrna, veće hektolitarske mase zrna, bolje otpornosti na polijeganje u odnosu na standardne kultivare Sladoran i Plaisant. Analiza slada ukazuje da je ovaj ječam dobre pivarske odlike, bolji od standardnih kultivara Sladorana i Plaisanta. Parametri strabilnosti uroda zrna hektolitarske mase zrna i mase 1000 zrna ukazuju na povoljnu reakciju kultivara Viktor prema različitim uvjetima proizvodnje. Ovaj kultivar je većeg uroda zrna, veće hektolitarske mase zrna i mase 1000 zrna u svim uvjetima proizvodnje u odnosu na prosjek pokusa, a u povoljnijim uvjetima uzgoja urod zrna i hektolitarska masa zrna imaju tendenciju povedanja (b > 0)., Two-rowed winter barley cultivar Viktor (registered in 1996) in the experiments of the Sort Commission, the Ministry of agriculture and forestry of the Republic of Croatia showed higher grain yield and hectolitre weight, it has more homogeneity grain and better resistance to lodging compared to the standard cultivars Sladoran and Plaisant. Malt analysis pointing that this is barley with good brewer's characteristics, better than standard cultivars Sladoran and Plaisant. Stability parameters of grain yield, hectolitre weight and weight of 1000 kernels show positive reaction for Victor cultivar under different conditions of production. This cultivar has higher grain yield, greater hectolitre weight and weight of 1000 kernels in all conditions of production compared to trials average. In favourable growth conditions grain yield and hectolitre weight tending to increase (b>0).

U svrhu istraživanja uroda zrna i kakvoće slada osječkih kultivara ozimog i jarog ječma, te opravdanosti namjenske proizvodnje kultivara i odlike ječma (ozimi ili jari) za potrebe sladarstva i pivarstva provedena su ispitivanja na Poljoprivrednom institutu u Osijeku u razdoblju od 1987/88. do 1989/9. godine, a mikrosladenje je obavljeno u Institutu za hmeljarstvo in pivovarstvo u Žalecu. Indeksom (a) su prikazani urod zrna (Qᵤ) i kakvoća slada (Qks), te ukupna vrijednost kultivara (Quvk) s obzirom na urod zrna i kakvoću slada u kultivara ozimog i jarog ječma. Kakvoća slada procijenjena je parametrima: sadržaj ekstrakta F.M., razlika ekstrakta fine i grube meljave, Kolbachov broj i viskozitet. Ustanovljeni su veći i stabilniji urodi zrna u kultivira ozimog ječma, a bolja i ujednačenija kakvoća slada u kultivara jarog ječma. U namjenskoj proizvodnji ječma za potrebe sladarstva i pivovarstva opravdano bi bilo uzgajati kultivare janog ječma Vitez i Astor, a kod ozimog ječma liniju Osk. 4.208/2-84 i kultivar Rex, a na što ukazuju veći indeksi ukupne vrijednosti kultivara (Quvk) i povoljniji odnosi indeksa Qks (kakvoće slada) i Qᵤ(uroda zrna)., In order to test grain yield and malt quality of Osijek varieties of winter and spring barley and to justify the choice of a particular variety and type (winter vs. spring) of barley for production of malt and beer, test trials were carried out at Agricultural Institute Osijek during 1987/88 and 1989/90 growing season. Micromalting was carried out at the Hop and Beer Production Institute at Žalec. Grain yield, malt quality and overall variety value were shown by indices Qu, Qks and Quvk respectively. Malt quality was evaluated by the following parameters: extract content F.M., the difference between extracts obtained by fine and rough milling, Kolbach's number and viscosity. Higher and more stable yield were observed in winter barley, while spring barley had better and more uniform malt quality. Barley growing for malt and beer production has to be based on spring barley varieties Vitez and Astor, and winter barley breeding line OSK 4.208/2-84 and variety Rex. These varieties have shown higher overall variety value indices (Quvk) and better ration between malt quality index (Qks) and grain yield index (Qu).

Despite decades of extensive research, beer flavour instability remains a challenge for both brewing and malting industries. Malt impacts the brewing process as well as the quality of the final beer. It also affects the stability of beer flavour, as it delivers to the brewing process various compounds with the potential to compromise the desired flavour characteristics of beer. These include staling aldehydes and their precursors, such as amino acids, reducing sugars, α-dicarbonyls and bound-state aldehydes. In general, the content of these compounds depends on barley variety and quality, the malting regime and final malt quality. Malt that represents a low potential for beer staling, i.e. that has low values of Kolbach Index, heat load, colour, LOX activity, Strecker aldehydes, transition metal ions and high antioxidative activity, leads to beer with enhanced flavour stability. However, the consistent production of malt with the desired quality remains challenging. Approaches to achieve this include adjustment of steeping and germination conditions, allowing control of grain modification and thus, the reservoir of aldehydes precursors. Also, the application of alternative kilning technologies may reduce the applied heat load, responsible for the formation of staling aldehydes and triggering development of the oxidising free radical species. This review provides an evaluation of current knowledge on the contribution of the malting process and malt quality to the formation of beer staling aldehydes. © 2021 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling.

A small-plot field experiment was set up during 2011, 2012 and 2013 to test the effect of nitrogen (N) fertilizers and nitrogen fertilizers combined with sulphur (S) in the nutrition of spring barley cv. Bojos. The following parameters were studied, the effect of fertilization on grain yield, specific weight, percentage of the grain retained on a 2.8 mm and 2.5 mm sieve, the content of starch and proteins, and the percentage of protein fractions. Also the influence of weather conditions on the studied parameters was evaluated. Starch content and specific weight of grain were not influenced by the fertilizer applied. Grain yield was rising until the overall dosage reached 50 kg N/ha and 21 kg S/ha while any higher rate of fertilizer reduced the yield. The percentage of A- and B-hordeins increased and the con­tent of C- and D-hordeins reduced as the fertilizer rate increased. A significant effect of weather on the monitored parameters as well as on the percentage of protein fractions was demonstrated. The results enabled a conclusion that there is no improvement in technological quality of barley grain once the optimal rate of fertilizer has been reached. The optimal rate is influenced by weather conditions during the growing season. © 2015 Institute of Agricultural and Food Information. All rights reserved., Internal Grant Agency of Faculty of Agronomy Mendel University in Brno [IP 18/2014]

J. Inst. Brew. 117(4), 541–546, 2011 Beer, a beverage frequently requested by celiac patients, is toxic to them due the gluten content derived from traditional raw materials used in the brewing process. To understand a possible alternative use of cereals and pseudo-cereals, micro-malting experiments on sorghum, buckwheat, quinoa and amaranth were performed using different malting parameters to study their brewing behaviour. Steeping in dilute NaOH solution was one parameter employed to understand any possible positive effect on malt quality. Alkaline steeping has been applied to pseudocereals for the first time and often showed an increase in total soluble nitrogen (TSN) and free amino nitrogen (FAN), especially with buckwheat, where two results showed the TSN content increased by about 500 and 1,000 mg/L. An interesting result was found with amaranth fermentability, which showed a fermentability of 56%, higher than what was previously reported. From these positive results for malt quality, it is possible to affirm that the cereals and pseudo-cereals investigated in this study could be employed for gluten-free beer production. Furthermore, the alkaline steeping seems to be a useful process variable for optimisation of malt quality. Future studies about its effect on the diastatic power could be conducted.

Background Grain protein content (GPC) is an important quality determinant for barley used as malt, feed as well as food. It is controlled by a complex genetic system. GPC differs greatly among barley genotypes and is also variable across different environments. It is imperative to understand the genetic control of barley GPC and identify the genotypes with less variation under the different environments. Results In this study, 59 cultivated and 99 Tibetan wild barley genotypes were used for a genome-wide association study (GWAS) and a multi-platform candidate gene-based association analysis, in order to identify the molecular markers associated with GPC. Tibetan wild barley had higher GPC than cultivated barley. The significant correlation between GPC and diastatic power (DP), and malt extract confirmed the importance of GPC in determining malt quality. Diversity arrays technology (DArT) markers associated with barley GPC were detected by GWAS. In addition, GWAS revealed two HvNAM genes as the candidate genes controlling GPC. No association was detected between HvNAM1 polymorphism and GPC, while a single nucleotide polymorphism (SNP) (798, P HvNAM2, was associated with GPC. There was a significant correlation between haplotypes of HvNAM1, HvNAM2 and GPC in barley. Conclusions The GWAS and candidate gene based-association study may be effectively used to determine the genetic variation of GPC in barley. The DArT markers and the polymorphism of HvNAM genes identified in this study are useful in developing high quality barley cultivars in the future. HvNAM genes could play a role in controlling barley GPC.