Malting Barley Varieties Research Articles

The Influence of Proteolytic Malt Modification on the Aging Potential of Final Wort.

The dynamic changes in beer flavor are determined by its aging potential, which comprises of present free and bound-state aldehydes and their precursors. Rising flavor-active aging compounds cause sensory deterioration (flavor instability). These compounds are mainly formed upstream in the brewing process through the Maillard reaction, the Strecker degradation, or lipid oxidation. Wort boiling is an especially critical production step for important reactions due to its high temperature and favorable pH value. Amino acid concentration, as an important aging-relevant precursor, is variable at the beginning of wort boiling, mainly caused by the malt modification level, and can further influence the aging potential aging formation during wort boiling. This study investigated the effect of the proteolytic malt modification level on the formation of precursors (amino acids and dicarbonyls) and free and bound-state aldehydes during wort boiling. Six worts (malt of two malting barley varieties at three proteolytic malt modification levels) were produced. Regarding precursors, especially Strecker, relevant amino acids and dicarbonyls increased significantly with an enhanced malt modification level. Concentrations of free and bound aldehydes were highest at the beginning of boiling and decreased toward the end. A dependency of malt modification level and the degree of free and bound aldehydes was observed for 2-methylpropanal, 2-methylbutanal, and 3-methylbutanal. Generally, a higher proteolytic malt modification level tended to increase free and bound aldehyde content at the end of wort boiling. Conclusively, the aging potential formation during boiling was increased by an intensified malt modification level.

Genetic dissection of a pericentromeric region of barley chromosome 6H associated with Fusarium head blight resistance, grain protein content and agronomic traits.

Fine mapping of barley 6H pericentromeric region identified FHB QTL with opposite effects, and high grain protein content was associated with increased FHB severity. Resistance to Fusarium head blight (FHB), kernel discoloration (KD), deoxynivalenol (DON) accumulation and grain protein content (GPC) are important traits for breeding malting barley varieties. Previous work mapped a Chevron-derived FHB QTL to the pericentromeric region of 6H, coinciding with QTL for KD resistance and GPC. The Chevron allele reduced FHB and KD, but unfavorably increased GPC. To determine whether the correlations are caused by linkage or pleiotropy, a fine mapping approach was used to dissect the QTL underlying these quality and disease traits. Two populations, referred to as Gen10 and Gen10/Lacey, derived from a recombinant near-isogenic line (rNIL) were developed. Recombinants were phenotyped for FHB, KD, DON, GPC and other agronomic traits. Three FHB, two DON and two KD QTLs were identified. One of the three FHB QTLs, one DON QTL and one KD QTL were coincident with the GPC QTL, which contains the Hv-NAM1 locus affecting grain protein accumulation. The Chevron allele at the GPC QTL increased GPC and FHB and decreased DON and KD. The other two FHB QTL and the other DON and KD QTL were identified in the regions flanking the Hv-NAM1 locus, and the Chevron alleles decreased FHB, DON and KD. Our results suggested that the QTL associated with FHB, KD, DON and GPC in the pericentromeric region of 6H was controlled by both pleiotropy and tightly linked loci. The rNILs identified in this study with low FHB severity and moderate GPC may be used for breeding malting barley cultivars.

Partitioning and Translocation of Dry Matter and Nitrogen During Grain Filling in Spring Barley Varieties and Their Roles in Determining Malting Quality.

To meet the strict requirements for the malting quality of both grain size and protein content for malting barley, a better understanding of the partitioning and remobilization of dry matter (DM) and nitrogen (N) from individual vegetative organs during grain filling may contribute to adjusting a balance in both quality parameters to satisfy the malting criteria of the brewing industry. A 2-year experiment that included 23 spring malting barley varieties was carried out to determine the DM and N partitioning in different organs at anthesis and maturity and to estimate their remobilization to grains. In contrast to the genetic variation of the 23 barley varieties, year effect was the most important single factor influencing the DM and N accumulation at pre-anthesis, and the DM and N translocation from their reserves at pre-anthesis. Post-anthesis assimilates accounted for 71–94% of the total grain yield among the barley varieties in 2014 and 53–81% in 2015. In contrast, the N reserved in vegetative tissues at anthesis contributed to barley grain N from 67% in the variety Union to 91% in the variety Marthe in 2014, and 71% in the variety Grace to 97% in the variety Shakira in 2015. The results concluded that photosynthetically derived assimilates at post-anthesis played an important role in determining grain size, whereas N reserves at pre-anthesis and N remobilization at post-anthesis probably determined the grain protein content of the malting barley. To achieve a high quality of malting barley grains in both grain size and protein content simultaneously, balancing photosynthetic assimilates at post-anthesis and N reserves at pre-anthesis and N remobilization should be considered as strategies for the combination of the selection of spring malting barley varieties together with agronomic N management.

Performance evaluation and stability analysis of malt barley (Hordeum vulgare L.) varieties for yield and quality traits in Eastern Amhara, Ethiopia

BackgroundBarley (Hordeum vulgare L.) is an annual cereal crop that belongs to the grass family Poaceae of the tribe Triticeae. It is the fifth most important cereal crop after teff, wheat, maize and sorghum in area coverage in Ethiopia. Important malting barley characteristics include kernel size, kernel protein content, extractable malt and diastatic power. Malt barely is an important crop in the study area; however, the productivity is low in the area varying from 15 kg ha−1 to 21 kg ha−1. The aim of the study was to identify high yielding, standard quality and stable malting barley variety to the study areas and similar agro-ecologies. Field experiments were conducted using eight improved malt barely varieties during the main cropping seasons (from the first week of July to end of October) in 2016 and 2017 at two selected sites Dehana (Amede work) and Lalibela (Medagai)) in north east Ethiopia. Data on grain yield and yield related traits, and quality attributes were recorded. Days to 50% heading (DH), and days to 90% maturity (DM) were recorded on plots basis. Plant height (PH, in cm), spike length (SPL, in cm), and number of seeds per spike (SPS) were measured on five randomly selected plants per plot of the central four rows. Mean grain yield (GY; grams of grain produced per plot, converted in kg ha−1), above ground dry biomass or biological yield (BY; dry weight of the above ground harvested biomass grams per plot, in kg ha−1) and thousand grain weight (TGW; weight of 1000 kernels, in grams) were measured on whole plots. Data were analyzed using SAS software program and significance of the mean difference was tested in least significant difference Test (LSD).ResultThe analysis of variance for grain yield and quality traits showed that the main effects of both genotypes and environments, and their interaction effect, were highly significant (P ≤ 0.01). The environment main effect accounted for 42%, 38% and 50% of the total grain yield, thousand kernel weight and kernel protein content variation, respectively. The average grain yield across varieties varied from 1652 kg ha−1 to 3377 kg ha−1.ConclusionsThree malting barley varieties (IBON174/03, EH1847 and Bahati) were found to be relatively high yielding, stable for grain yield and full fill the quality parameters. Therefore, these varieties are recommended for production. A further study is required on agronomic practices and brewing quality attributes in malt barley.

Transcriptome Alterations of an in vitro-Selected, Moderately Resistant, Two-Row Malting Barley in Response to 3ADON, 15ADON, and NIV Chemotypes of Fusarium graminearum.

Fusarium head blight caused by Fusarium graminearum is a devastating disease of malting barley. Mycotoxins associated with contaminated grain can be transferred from malt to beer and pose a health risk to consumers. In western Canada, F. graminearum has undergone an adaptive shift from 15ADON constituency to dominance by virulent 3ADON-producers; likewise, NIV-producers have established in regions of southern United States. Lack of adapted resistance sources with adequate malting quality has promoted the use of alternative breeding methodologies, such as in vitro selection. We studied the low-deoxynivalenol characteristic of in vitro selected, two-row malting barley variety “Norman” by RNAseq in contrast to its parental line “CDC Kendall,” when infected by 15ADON-, 3ADON-, and NIV-producing isolates of F. graminearum. The current study documents higher mycotoxin accumulation by 3ADON isolates, thereby representing increased threat to barley production. At 72–96-h post infection, significant alterations in transcription patterns were observed in both varieties with pronounced upregulation of the phenylpropanoid pathway and detoxification gene categories (UGT, GST, CyP450, and ABC), particularly in 3ADON treatment. Defense response was multitiered, where differential expression in “Norman” associated with antimicrobial peptides (thionin 2.1, defensing, non-specific lipid-transfer protein) and stress-related proteins, such as late embryogenesis abundant proteins, heat-shock, desiccation related, and a peroxidase (HvPrx5). Several gene targets identified in “Norman” would be useful for application of breeding varieties with reduced deoxynivalenol content.

Image Analysis Methods in Classifying Selected Malting Barley Varieties by Neural Modelling

Quality evaluation of products is a critical stage in the process of production. It also applies to the production of beer and its main ingredients, i.e., hops, yeast, malting barley and other components. The research described in this paper deals with the multifaceted quality evaluation of malting barley needed for the production of malt. The project aims to elaborate on the original methodology used for identifying grain varieties, grain contamination degree and other visual characteristics of malting barley employing new computer technologies, including artificial intelligence (AI) and neural image analysis. The neural modelling and digital image analysis assist in identifying the quality of barley varieties. According to the study, information concerning the colour of barley varieties presented in digital images is sufficient for this purpose. The multi-layer perceptron (MLP)-type neural network generated using a data set describing the colour of kernels presented in digital images was the best model for recognising the analysed malting barley varieties. The proposed procedure may bring specific benefits to malthouses, influencing the beer production quality in the future.

Performance Evaluation of Malt Barley (Hordeum vulgare L.) Varieties for Yield and Quality Traits in Eastern Amhara Regional State, Ethiopia

Barley (Hordeum vulgare L.) is an annual cereal crop that belongs to the grass family Poaceae of the tribe Triticeae. Due to the establishment and production capacity of malt and beer factories in Ethiopia, malt barley production demand increased from time to time. Eight released malt barley varieties were evaluated in four environments in Wag-himra and Lasta districts in the main production season for two years (2016 and 2017). The objective of the trial was to identify a high yielder and standard-quality malting barley variety for production. The trial was conducted using a randomized complete block design with three replications on a plot size of 1.2 m width with that of 2.5 m length. The results revealed that there was a highly significant difference in grain yield and quality traits ( p < 0.05 ). The kernel protein and starch content of the varieties ranged from 9.85 to 11 and 63–65%. The thousand kernel weight of the varieties was in the range of 32.5 to 46.4 g. EH1847 (3340 kg ha−1), IBON174/03 (3351 kg ha−1), and Bahati (3220 kg ha−1) were the first three best performing high yielder and best varieties that fulfilled quality parameter requirements set by the National Standard Authority for malting barley. Therefore, these varieties are recommended for production in the Wag-himra and Lasta agroecologies for their high yield, kernel size, and kernel protein content. Further study is required on agronomic practices and brewing quality attributes in malt barley.

Genetic Variation in Grain Yield and Quality Traits of Spring Malting Barley

Cultivation of malting barley is particularly challenging as the requirements of growers, for high yield, and that of the brewing industry, seeking a specific quality criteria, must be met simultaneously. Furthermore, significant genotypic and environmental variations in grain yield and quality properties may occur. To investigate the relationships between grain yield and quality parameters of spring malting barley, a 2-year experiment was carried out in order to characterise the genotypic and year effects on grain yield, quality properties, and yield components of 23 high-yielding varieties of spring malting barley under optimal nitrogen (N) fertilisation. Compared to the grain quality properties of the grain protein content and the grain retention fraction of grain size >2.5 mm, less genotypic and environmental variation in grain yield was observed. Grain yield was closely related to spikes per m2, suggesting the importance of tiller formation and establishment as a decisive factor influencing malting barley yields. A major interactive effect of genotypes and year on grain size was observed. Regarding weather effects, the global radiation intensity during the post-anthesis phase was the major factor affecting the final grain size in this study. Grain protein content was primarily dependent on the year effect, suggesting that optimal N fertilisation levels must vary between years to ensure the correct protein content required for the needs of the brewing industry is met. Therefore, we recommend further development strategies addressing N fertilisation and soil N mineralisation to optimise the production of spring malting barley.

Exploring dry grain fractionation as a means to valorize high‐protein malting barley

AbstractBackground and objectivesMalting barley cultivars are potentially the most profitable commodities for producers; however, barley selected for malting purposes has to meet many stringent quality requirements. Barley with excessive grain protein concentration (>13%) is often the reason why it is rejected for malting grade and sold at a lower price on the feed market. The objectives of this study were to explore dry grain fractionation as a means to valorize high‐protein malting barley by producing high fiber/protein fractions for human nutrition and starchy fractions for adjunct brewing.FindingsSeveral malting barley varieties with grain protein concentration above 14% (db) were milled on a Buhler laboratory mill resulting in six flours streams. Coarse and fine shorts were further processed using a Buhler laboratory shorts duster resulting in coarse fiber fractions and two additional flour fractions. The total yield of combined flour fractions ranged from 50.2% to 51.6%, whereas the yield of fiber fractions ranged from 41.5% to 43.7%. The fiber fractions were enriched in β‐glucans (9.3%–11.2%, db), arabinoxylans (9.9%–11.3%, db), and proteins (22%–26%, db) with average 2.2‐, 1.7‐, and 1.5‐fold increase of these constituents, respectively, compared to the whole grain. The content of vitamin E in fiber fractions was higher than in the whole grain, ranging from 82 to 109 ug/g. The fiber fractions also exhibited an improved ratio of tocotrienol to tocopherols. The combined flour fractions were depleted of β‐glucans (0.6%–0.7%, db) and arabinoxylans (0.5%–0.6%, db), contained acceptable levels of proteins (11.5%–13.5%, db) and high levels of starch (79%–82%, db). Mashing experiments with up to 40% replacement of malt with flour fractions showed significant improvements in malt extract without negative influence on malting quality parameters, such as wort beta‐glucans, wort viscosity, and the average degree of polymerization of starch dextrins.ConclusionsThe study demonstrated that covered barley can be milled using milling equipment commonly used in wheat milling without the necessity of prior dehulling of the grain. The milling resulted in two high‐yield fractions (flour and fiber/protein‐rich fractions) with hulls effectively separated during the early stages of milling, making the fractionation process commercially feasible.Significance and noveltyHigh‐protein barley can be valorized by fractionation into fiber/protein‐rich fractions that can be used as valuable food ingredients for the effective and economical control of many food‐related health issues and into starchy flour fractions that can used as adjunct in brewing.

Identification of QTL for barley grain size.

BackgroundBarley grain size is one of the key factors determining storage capacity during grain filling. Large, well-filled grains also have a high malt extract potential. Grain size is a complex quantitative trait and can be easily affected by environmental factors thus the identification of genes controlling the trait and the use of molecular markers linked to the genes in breeding program is the most effective way of improving grain size.MethodsGrain sizes of 188 doubled-haploid (DH) lines derived from the cross of a Japanese malting barley variety (Naso Nijo) and a Chinese feed barley variety (TX9425) were obtained from three different sites in two consecutive years. The average data were used for identifying QTL for grain size.ResultsA total of four significant QTL were identified for grain length (GL) and three for grain width (GW). The two major GL QTL are located at similar positions to the QTL for malt extract on 2H and uzu gene on 3H, respectively. However, the GL QTL on 2H is more likely a different one from the malt extract QTL as most of the candidate genes are located outside the fine mapped QTL region for malt extract. The GL QTL on 3H is closely linked with uzu gene but not due to a pleiotropic effect of uzu. The three QTL for grain width on 1H, 2H and 5H, respectively, were located at same position to those for GL.

Evolution of folate content during barley malt production

AbstractThe aim of this research was to study the effect of micro- and industrial scale malting on the folate content of barley. Two malting barley varieties (one spring and one winter) were studied, applying the same technology. Furthermore, a roasting experiment was carried out at given temperatures for different time periods. The total folate content was determined by microbiological method. The folate content of the barleys was between 10.1 and 23.4 µg/100 g dry matter. For micro- and industrial scale, malting folate content increased 6.5–8-fold and 4–7-fold, respectively, during the malting process. An unexpected result was observed during industrial malting: the folate content increased during kilning by 18–35%, unlike micro scale malting, where a 15–20% decrease was observed. Results obtained during roasting showed that folic acid content did not decrease when roasted for 20 min at 100 °C, but it decreased linearly with increasing temperature. Folate is completely degraded in 20 min at 200 °C. It can be stated that barley malt can serve as a relatively good source of folate, but barley variety and malting technology have significant impact on it.

Problems and possibilities of studying malting quality in barley using molecular genetic approaches.

About one-third of the world’s barley crop is used for malt production to meet the needs of the brewing industry. In this regard, the study of the genetic basis of malting quality traits and the breeding of malting barley varieties that are adaptive to their growing conditions are relevant throughout the world, particularly in the Russian Federation, where the cultivation and use of foreign malting varieties of barley prevails. The main parameters of malting quality (artificially germinated and dried barley grains) are malt extract, diastatic power, Kolbach index, viscosity, grain protein, wort β-glucan, free amino nitrogen, and soluble protein content. Most of these components are under the control of quantitative trait loci (QTLs) and are affected by environmental conditions, which complicates their study and precise localization. In addition, the phenotypic assessment of malting quality traits requires elaborate, expensive phenotypic analyses. Currently, there are more than 200 QTLs associated with malting parameters, which were identified using biparental mapping populations. Molecular markers are widely used both for mapping QTL loci responsible for malting quality traits and for performing marker-assisted selection (MAS), which, in combination with conventional breeding, makes it possible to create effective strategies aimed at accelerating the process of obtaining new promising genotypes. Nevertheless, the MAS of malting quality traits faces a series of difficulties, such as the low accuracy of localization of QTLs, their ineffectiveness when transferred to another genetic background, and linkage with undesirable traits, which makes it necessary to validate QTLs and the molecular markers linked to them. This review presents the results of studies that used MAS to improve the malting quality of barley, and it also considers studies that searched for associations between genotype and phenotype, carried out using GWAS (genome-wide association study) approaches based on the latest achievements of high-throughput genotyping (diversity array technology (DArT) and single-nucleotide polymorphism markers (SNPs)).

Technological assessment of the suitability of domestic raw materials for beer production as an important link in the country’s food security

The existing malting barley varieties differ in their quality and technological characteristics depending on the peculiarities of cultivation, soil and climatic conditions. In the work, there were four varieties of malting barley: Beatrice, Vorsinsky, Grace and Margret. They were evaluated according to the physical and chemical indicators established by regulatory documents for this grain. It has been determined that Vorsinsky variety contains protein that is a technologically important component above the normalized value. This problem is solved during germination of the grain due to active influence of proteolytic enzymes of the grain on protein. In this connection, it is necessary to create conditions intensifying a technological process of malting, provoking strengthening of biochemical transformations. On this basis, the use of organic acids complex at the stage of barley soaking is justified, which should be applied to the last retted water in the amount of 10−9 mol/dm3 and barley should be kept with it for six hours. This speeds up physiological and biochemical transformations in the grain. The effectiveness of this treatment was confirmed by an example of increase in the enzymatic activity. The possibility of obtaining barley malt on the basis of the proposed varieties with high quality characteristics in accordance with the requirements of the malt standard is shown. The expediency of regulation of the chemical composition of barley malt of Vorsinsky variety by means of an organic stimulator is shown, which allows obtaining malt with indicators not inferior to those of other studied varieties. The use of an individual approach to certain barley varieties at the malting stage will expand the raw material base of the brewing industry and provide the industry with domestic malt.

The Structure of the Barley Husk Influences Its Resistance to Mechanical Stress.

This paper explores the links between genotype, plant development, plant structure and plant material properties. The barley husk has two organs, the lemma and the palea, which protect the grain. When the husk is exposed to mechanical stress, such as during harvesting, it can be damaged or detached. This is known as grain skinning, which is detrimental to grain quality and has a significant economic impact on industry. This study focused on the lemma, the husk organ which is most susceptible to grain skinning. This study tested three hypotheses: (1) genotype and plant development determine lemma structure, (2) lemma structure influences the material properties of the lemma, and (3) the material properties of the lemma determine grain skinning risk. The effect of genotype was investigated by using plant material from four malting barley varieties: two with a high risk of grain skinning, two with a low risk. Plant material was assessed at two stages of plant development (anthesis, GS 65; grain filling, GS 77). Structure was assessed using light microscopy to measure three physiological features: thickness, vasculature and cell area. Material properties were approximated using a controlled impact assay and by analyzing fragmentation behavior. Genotype had a significant effect on lemma structure and material properties from anthesis. This indicates that differences between genotypes were established during floral development. The lemma was significantly thinner in high risk genotypes, compared to low risk genotypes. Consequently, in high risk genotypes, the lemma was significantly more likely to fragment. This indicates a relationship between reduced lemma thickness and increased fragmentation. Traditionally, a thin husk has been considered beneficial for malting quality, due to an association with malt extract. However, this study finds a thin lemma is less resistant to mechanical stress. This may explain the differences in grain skinning risk in the genotypes studied.

Breeding and brewing quality of the Canadian malting barley variety 'CDC Goldstar' lacking lipoxygenase-1.

Various types of malt quality profiles have been investigated to benefit the North American brewing industry. Herein, we report the development and brewing quality of the hulled, two-row malting barley (Hordeum vulgare L.) variety ‘CDC Goldstar’ lacking lipoxygenase-1 (LOX-1-less). This new variety offers a novel malt type for the improvement of beer flavor stability. The agronomic performance of ‘CDC Goldstar’ was tested in the Western Cooperative Two Row Barley Registration Trials during 2013–2014. In addition to high lodging tolerance, the new variety showed 6% higher yield than the current leading variety ‘CDC Copeland’. The malt quality of ‘CDC Goldstar’ showed higher diastatic power and lower wort β-glucan content than ‘CDC Copeland’ and controllable proteolytic modification (soluble nitrogen and Kolbach Index). Pilot- (100 L) and commercial-scale (5,000 L) brewing trials were conducted using ‘CDC PlatinumStar’, another LOX-1-less variety with a low enzymatic profile, as the control variety. Absence of the LOX-1 trait from ‘CDC Goldstar’ maintained trans-2-nonenal levels in aged beers as low as those in other LOX-1-less varieties without affecting major beer parameters, such as ester and aldehyde content or foam stability. The newly developed ‘CDC Goldstar’ malting barley provides added value for the beer industry and consumers.

JAU-17: A First High Yielding Malting Barley Variety Suitable for Marginal Lands of Punjab

For the usage of beverages and malting purpose, Wheat Research Institute, Faisalabad, developed the ever first variety of barley crop with the name JAU-17 in Pakistan. It is a two rowed barley variety performed best in a series of irrigated and rain fed yield trials conducted at Wheat Research Institute, Faisalabad and outstation yield trials throughout the Punjab province. During yield trials for three consecutive years from Preliminary to Regular and advanced Yield Trials, it has out-yielded the Check Variety Haider-93 by an average of 23.37% while in Outstation Yield Trials throughout the Punjab province, it produced 11.5% higher grain yield than commercial Check variety Haider-93. JAU-17 has medium to tall stature of about 99 to 110 cm length, growth habit is semi erect and has medium-length-awned ear which has yellowish white color. It takes 90 to 100 days to complete heading and matures in 140 to 145 days. It bears good tillering capacity (154-160 per m). The seed is amber in color with 1000-grain weight of upto 42 gram. For quality trait evaluation it has good quantity for protein (12.2 to 13.7%) and test weight (52.7 to 54.4 kg/hl) along with opaque seed surface. Its malt making quality is excellent for industrial uses. In 2019 Jau-17 was approved by Punjab Seed Council for general cultivation due to its stable performance over the years for better grain yield, resistance against rusts and nutritional quality.

Openness in Malting Barley Value Chains: The Case of Adoption of new Varieties in Canada and the United Kingdom

Development of new malting barley varieties depends crucially on value chain acceptance. A case study analysis of the adoption of new varieties in malting barley value chains in Canada and the United Kingdom (UK) indicates that openness in value chains is a major contributing factor to a faster adoption rate for new varieties, even if firms conduct R&D in-house. Drawing upon the open innovation literature, this paper applies four degrees of openness framework across two dimensions: a firm's level of openness in innovation strategy, and its degree of openness with the rest of the industry.

Novel QTL Conferring Phosphorus Acquisition and Utilization Efficiencies in Barley.

Phosphorus (P) deficiency in agricultural soil is a major constraint for crop production and increasing P acquisition efficiency (PAE) of plants is considered as one of the most cost-effective solutions for yield increase. The objective of this study was to detect quantitative trait loci (QTL) controlling (PAE) and P utilization efficiency (PUE) in barley under applied (+P) and non-applied P (−P) conditions. Based on the analysis of a recombinant inbred lines (RILs) population derived from a cross between a malting barley variety and a wild barley accession, 17 QTL controlling PAE, PUE and yield traits were detected. The phenotypic variation explained by each of these QTL ranges from 11.0 to 24.7%. Significant correlation was detected between most of P-related traits and yield traits. Five QTL clusters were identified on four different chromosomes (1H, 3H, 5H, and 7H). Two of the QTL clusters, located on chromosome 1H (for GPUP/PUP) and 7H (for SPUE/SPC), respectively, are novel. Fourteen genes located in the interval harboring the major QTL were identified as candidates associated with P efficiency. The stable QTL for PAE, PUE and yield-related traits could be important for breeding P-efficient barley varieties.

Quantitative and Qualitative Composition of Bacterial Communities of Malting Barley Grain and Malt during Long-Term Storage

In the grain samples of three malting barley varieties harvested in 2016, and in the malt made from them, we observed microbial changes during storage. Analyses were performed after 0, 3, 6, and 9 months of storage in floor warehouses and silos. We monitored microbial changes based on the quantitative determination of microorganisms using a plate dilution method and qualitative determination of microorganisms, where we identified a particular species of bacteria using the MALDI-TOF MS Biotyper instrument (Bruker Daltonics, Bremen, Germany). Based on the quantitative determination of microorganisms, we found that the total plate counts of microorganisms was higher in malts than in barley grains. The storage period had the greatest impact on the number of coliform bacteria, which gradually increased with the growing months in storage. The number of lactic acid bacteria in barley grains with the growing months in storage and malt produced from them decreased slightly, and the content of the sporulating bacteria in all the samples fluctuated slightly. Differences in the numbers of observed microorganisms were negligible during storage between floor warehouses and silos. In the samples of barleys, the most commonly identified species were Pantoea agglomerans, which was also present in malt samples but did not belong to the dominant species. A diverse species representation appeared in the samples, whereas predominating species belonged to the Enterobacteriaceae family.

Determination of Cytolytic Malt Modification – Part I: Influence of Variety Characteristics

The malt criteria of viscosity and β-glucan are used as an integral part of routine laboratory control measures to classify the cytolytic malt modification level and to ensure good processability. To optimize separation processes in general, the main focus of barley breeding has been on intensifying the cytolytic modification level and reducing the β-glucan concentration. However, not all new malting barley varieties show good processability despite a low β-glucan content, since the effect of hemicellulose constituents such as arabinoxylan and their enzymatic hydrolysis are largely disregarded. For this reason, the aim of the present work was to investigate the individual cytolytic composition of different malting barley (malt) varieties and to point out differences in cytolytic malt parameters depending on their genetically determined modification level. Appropriate analytical possibilities for arabinoxylan determination and suitable extraction methods for cytolytic evaluation have been further shortcomings in breeding quality control. In addition, the most important cytolytic degrading enzymes have been characterized in this paper. Part one of this two-part study demonstrated that cytolytically highly modified varieties have a lower β-glucan but in consequence a higher arabinoxylan content. With regard to the activity of enzymes, the results suggested small differences in β-glucanase, but not in arabinofuranosidase and xylanase. Finally, a principal component analysis showed that most of the cytolytically highly modified barley varieties (52%) were affected by arabinoxylan. The first part of the paper confirms that while breeding progress has reduced β-glucan, arabinoxylan has become the more dominant impact factor on processability.