Malting Quality Research Articles

Genetic basis of barley contributions to beer flavor

Barley malt is critical for the malting, brewing, and distilling industries, as it is one of the main ingredients of beer and some types of spirits. There is growing evidence that barley genotype - via malt - can impact the flavors of beers and spirits. However, information on the barley genes involved in these flavors is lacking. Therefore, we used quantitative trait locus (QTL) mapping of malt quality traits, beer sensory descriptors and metabolic compounds on a biparental population of doubled haploids derived from the cross of the cultivars Golden Promise and Full Pint. Putative candidate genes for QTLs were identified by alignment with the reference barley genome sequence. There were thirty-seven QTLs across all chromosomes except 4H, with three QTL clusters located on 3H (1 cluster) and 5H (2 clusters: mid-5H and end-5H). Those “hotspots” contained QTLs for multiple phenotypes. Several candidate genes that regulate plant metabolism were identified within the QTLs and included HvAlaAT, HvDep1, HvMKK3, HvGA20ox1 and HvGA20ox2. These genes are involved in seed dormancy and plant height. Alleles at these loci, and perhaps at physically linked loci, can have key downstream effects on malting quality, beer flavor, and abundance of volatile metabolites.

Effects of mixed intercropping on the agronomic parameters of two organically grown malting barley cultivars (Hordeum vulgare) in Northwest Germany

The market for organic malting barley (Hordeum vulgare L.) is growing. One goal of producing malting barley is to attain a defined protein content. This is challenging in organic farming because nutrient uptake is unpredictable. Since malting barley is quality sensitive to high amounts of available nitrogen (N) during the grain filling phase, artificial competition for N from a second crop within a mixed intercropping system could help to limit N uptake during these later growing stages. The objective of this study was to evaluate the effects of intercropping on the brewing quality parameters of malting barley within the framework of organic farming. In a field trial, with two spring barley cultivars (Odilia, Marthe) as sole crops and in intercropping treatments of 4 intermediate mixing ratios with camelina (Camelina sativa), linseed (Linum usitatissimum) and pea (Pisum sativum), the effects on yield and malting quality were observed. The results from three growing seasons on a study site in north-western Germany showed an opposite protein response for mixtures with linseed and pea. However, sole stands of barley mostly performed as well as the mixtures. For mixtures with camelina, neither yield nor quality aspects were affected. Comparing the two cultivars, the well-established Marthe, from traditional conventional selection, showed the better overall performance with a 13% higher grain yield, a 3% higher hectoliter weight and 5% higher proportion of size fraction > 2.5 mm than Odilia, which was released later from an organic breeding program. However, the yield component analysis showed a consistent yield determination for Odilia regardless of intercropping partner or mixing ratios which might indicate its suitability in polycultures. The observed average land equivalent ratios (LER) of mixtures with linseed (1.04) and pea (1.13) showed the potential to increase land-use efficiency but were lower compared to the mean LER found in a recent meta-analysis.

Yield and malt quality of barley (Hordeum vulgare) impacted by nitrogen and sulphur application

The study aimed to investigate the effect of different levels of nitrogen (N) and sulphur (S) doses on growth, yield and malt quality of different barley (Hordeum vulgare L.) varieties grown on loamy sand soil. A field experiment was conducted during rabi 2015-16 and 2016-17 with three barley varieties (RD-2668, DWRUB-52 and RD-2849), three levels of N (60, 90 and 120 kg/ha) and three levels of S (0, 10 and 20 kg/ha). The experiment was laid down in a factorial randomized block design with three replications. Result indicated that the barley variety RD-2849 recorded the highest growth, yield and malt quality compared to other varieties. Among the nutrients management practices, application of 120 kg N/ha and 20 kg S/ha documented the maximum growth and yield characters as well malt quality in barley, irrespective of varieties. Cultivation of barley variety RD-2849 with the application of 120 kg N/ha and 20 kg S/ha explore the maximum varietal potential under loamy sand soils of Rajasthan.

Malting Performance of Landrace Barley and Wheat Grown in Nigeria Using Long and Short Steeping Regimes

A longer steeping regime is advocated when malting elite barleys. A shorter steeping regime used in this study produced good hot water extract (HWE), fermentability, fermentable extract (FE), free amino nitrogen (FAN), peptide nitrogen (PN), and predicted spirit yield (PSY) from malted and mashed barley and wheat. High germination energy (GE)–germination test and good germination performance during the malting process resulted in the production of good quality malt. A high nitrogen content (less starch), lower screening of grains >2.5 mm (thin grains) of barley and wheat, and especially, the high husk (14.8%) of the barley further confirmed that mashing thin grains can cause lower PSY from the malted barley or wheat. The steeping regime influenced glucose to maltose ratios, resulting in higher glucose to maltose ratios. The glucose to maltose ratio is important for effective yeast fermentation. Complimentary results from FAN and PN supported yeast fermentation. Malted barley gave higher PSY results at both steeping regimes. Malted Nigerian-grown wheat gave higher PSY results than imported wheat, when short or longer steeping was used in malt production. This could be linked to differences in the starch structures in the wheat samples studied. The shorter steeping produced good quality malt. This could save costs in terms of energy use, water use, and carbon dioxide release from respiring embryos during steeping and germination. For optimum advantage of the shorter stepping regime to be achieved, good quality grain must be selected to reap the full benefit in using a shorter steeping regime to produce good malt.

Industrial evaluation for malting quality of Indian barley varieties

Barley is a preferred cereal for malt making and specialized varieties are required to get superior product quality in industrial malting and brewing uses. The Indian malt barley improvement programme has developed several varieties for this specific purpose. In this study eight malting barley varieties were got evaluated by four malt barley industries in their analysis. Based upon the overall performance, the varieties DWRUB 52, DWRB 101 and DWRB 91 in two-row and DWRUB 64 and DWRB 137 in six-row group were found most suitable with recent industrial specifications. The diastatic power in two rowed genotypes needs to be improved and β-glucan in grain or wort needs to be further lowered in view of the current industrial preferences.

Exploring Fungal Species Diversity in the Premature Yeast Flocculation (PYF) of Barley Malt Using Deep Sequencing

Premature yeast flocculation (PYF) is the early flocculation of yeast during fermentation, which causes logistical and financial hardship to the malting and brewing industries. The occurring of PYF is suspected to be caused by the fungal infection of the barley or at least in part. The aim of this study was to perform a non-culture approach to uncover the fungal diversity in PYF malt. The genomic DNA was extracted and analyzed by amplicon sequencing. A total pairs read number of 209,523 sequences was obtained and used for taxonomic classification. The dominant fungal communities on the PYF malt were obtained based on the microbial diversity analysis by species annotation. The internal transcribed spacers sequencing analysis showed a decreased number of fungal species in PYF malt. Results showed that compared with control malt, PYF malt displayed a higher abundance of Ascomycota at the phyla level, and the abundance of Candida and Gibberella was exceptionally high in two PYF malts at the genus level. The absolute abundance of Candida and Gibberella baccata at the species level was also higher in PYF malts. The fungal species diversity within the malt indicated that the fungi community diversity was greater in the control malt than in the PYF malt. Taken together, exploring the diversity of the fungal community could be useful for malt quality control and for eliminating contamination risks.

Review on Effect of Genotype x Environment Interaction and Yield Stability Among Sorghum (<i>Sorghum bicolor (L.) </i>Moench.) Genotypes

Sorghum is a prominent cereal crop, particularly in the world's semi-arid tropics. It is grown in over 105 countries across Africa, Asia, Oceania, and the Americas on 40 million hectares. Sorghum is an important indigenous food crop, second only to teff in terms of production of injera (leavened native flat bread). The majority of sorghum varieties are recommended for various agro ecological zones (AEZs), and no single variety is appropriate for all of Ethiopia's circumstances (GxE). GxE affects grain yield, nutritional quality and content, as well as physicochemical and malting quality. The interaction of an organism's genetic composition with its environment results in phenotype, which is a physical trait. The presence of GEI complicates the selection of yield and yield-related traits. GEI can inhibit progress in the selection process and is a key driver of genotype-to-genotype yield stability differences. Plant breeders should investigate GEI in order to better understand crop development in relation to biophysical conditions. In different agro-ecologies, locales, and seasons, genotypes will respond differently. Agronomic/dynamic stability refers to a genotype's ability to adapt to changes in the environment. Breeders should encourage the development of varieties/hybrids that can adapt to a wide range of environments. Crossover and non-crossover gene x environment interactions (GEI) are the two forms of GEI. When there is a disparity in genotypic performance between individuals. Statistical analysis of yield studies can help agronomists, breeders, and other agricultural specialists make faster progress. G x E Interaction and Stability Analysis permits genotypes' relative performance and stability for yield and yield-related variables to be assessed. Therefore the objective of this review study is to assess the role of G x E on yield stability of sorghum.

Chevalier barley: The influence of a world‐leading malting variety

AbstractDuring the 19th century, ‘Chevalier’, said to have been developed from a single plant found in 1820, was the world‐leading malting barley (Hordeum vulgare). The superior malting quality of Chevalier lead to its world‐wide spread at the time of the development of the malting industry. In this study, we investigate how this cultivar was spread and adopted to Nordic seed systems of the time. Single nucleotide polymorphism genotyping of up to 155‐yr‐old museum specimens of historical grains labelled “Chevalier” and of Chevalier accessions preserved in genebanks, in total 282 individuals representing 47 accessions, allowed us to divide the accessions into four categories: True Chevalier, seed mixtures, crosses, and non‐Chevaliers. Comparisons with previously genotyped Nordic landraces showed how, in the 19th century, Chevalier seed was mixed with locally produced landrace seed and cultivated together. We suggest that spontaneous outbreeding events gave rise to hybrids which were subsequently selected and propagated when resulting in superior genetic combinations. Such farmer‐driven breeding activities would have preceded modern plant breeding but resembled the breeding principles that were later used, even though the scientific understanding of inheritance was not yet known.

Optimizing the choice of test locations for multitrait genotypic evaluation

AbstractPlant breeding programs expend significant resources on multilocation testing to evaluate genotypes for advancement or potential cultivar release. The selection of genotype entries for these trials is typically based on previous phenotypic data or predictions; yet locations, important contributors to nongenetic variation, are often chosen in a less data‐driven manner. Using agronomic and quality trait data from two long‐term regional barley (Hordeum vulgare L.) nurseries, our objectives were (a) to measure the precision, repeatability, and representativeness of test locations based on multitrait data and (b) to optimize the selection of test locations for use in future trials. When considering traits individually, ideal locations could be identified simply, but a combined analysis of 11 traits indicated that very few locations were broadly favorable, and considerable tradeoffs are necessary. We developed a flexible optimization procedure to select the locations based on their precision, repeatability, and representativeness for multiple traits while simultaneously constraining the total number of locations. Optimization led to a 58–75% reduction in the number of locations, and therefore phenotyping costs, with little loss in data utility. Importantly, our approach allowed locations to be selected for phenotyping different sets of traits (e.g., either agronomic or both agronomic and malting quality), mimicking the often nested structure of trait data collection. This approach may be useful for individual plant breeding programs or collaborations wishing to increase the resource efficiency of these important regional evaluation trials.

Effect of malting process duration on malting losses and quality of wheat malts

Abstract The study assesses impact of malting process duration on malting losses and quality of malts obtained from three varieties of winter wheat, i.e., Elixer, Rockefeller and Gimantis. The findings show that increased duration of the malting process (from 4 to 7 days) corresponded to greater total weight loss, with the most significant differences observed between 5-day and 6-day wheat malts. The qualitative analysis of the malts was carried out in accordance with EBC methodology. The assessments showed that the 5-day long malting process applied to the relevant wheat varieties resulted in production of high-quality malt with optimum malting losses observed in the case of Elixer and Rockefeller varieties. Slightly higher malting losses were identified in the case of Gimantis, and the malt obtained from this variety had very high contents of soluble protein (on average 5.34% d.m.) and Kolbach Index (average of 50.49%), which reflects high proteolytic activity during the grain malting process and a need to modify the malting process for this variety.

A Malting Barley (Hordeum Vulgare L.) Variety, ‘Nurimaeg’ with Resistance to Barley Yellow Mosaic Virus and Tolerance to Lodging Stress

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA malting barley variety, ‘Nurimaeg’, was developed with resistance to barley yellow mosaic virus (BaYMV), tolerance to lodging stress, and good brewing quality. ‘Nurimaeg’ was developed by crossing Milyang127 and Miharu gold in 2004. Regional yield trials were conducted for ‘Nurimaeg’ as a breeding line ‘Iksan175’ in four different regions from 2014-2016. It has a type I growth habit, and its average heading and maturity dates were April 12 and May 20, respectively-which were 1 day later than the maturity date of ‘Hopum’ variety. As ‘Nurimaeg’ has a shorter culm length (77 cm) than that of ‘Hopum’, it showed tolerance to lodging stress. This variety possesses the rym5 gene and is resistant to BaYMV. It showed a 42.9 g 1000-grain weight and 90% assortment ratio. The yield potential of ‘Nurimaeg’ was 408 kg/10a, which is approximately 18% higher than that of ‘Hopum’. Analysis of grain quality for malting showed that ‘Nurimaeg’ has high quality of low protein and β-glucan content. Malt quality analysis revealed that it has 72.8% extract, 4.2% soluble protein, 38.9% kolbach index, and 243 WK diastatic power, which all were similar to those of ‘Hopum’. ‘Nurimaeg’ would be suitable for cultivation in the areas of Korea that have a daily minimum temperature of -4℃ in the month of January (Registration No. 7960).Keywords : malting barley, BaYMV resistance, lodging resistance, malt, variety

Interactions of the barley SD1 and SD2 seed dormancy loci influence preharvest sprouting, seed dormancy, and malting quality

AbstractPreharvest sprouting (PHS) can severely damage barley (Hordeum vulgare L.) malting quality and is of particular concern in locations with a high frequency of precipitation around harvest. Malting quality and PHS resistance are often negatively correlated, and the SD2 locus on chromosome 5H has been associated with both traits. Using three spring barley populations, PHS, seed dormancy, and germination rate were mapped over six time points to identify changes in genetic control of these traits during the after‐ripening period. HvAlaAT1 at the SD1 locus was associated with long‐term dormancy and reduced germination rate. Ninety lines were Sanger sequenced for HvGA20ox1, but variants were not associated with PHS or germination traits. The allelic state of HvMKK3 was strongly associated with genetic PHS susceptibility in North American spring two‐row barley germplasm and interactions between HvAlaAT1 and HvMKK3 were associated with changes in seed dormancy and germination rate over time. Several malting quality traits were associated with HvMKK3 alleles. Kompetitive allele‐specific polymerase chain reaction (KASP) markers were developed for the causal mutations in HvAlaAT1 and HvMKK3 and a diagnostic mutation in HvGA20ox1. Haplotypes with PHS resistance, short primary dormancy, and a high germination rate were identified that could be useful for breeding for PHS resistance and malting quality.

The Effect of Using Biological Treatment on Microbial Growth during the Malting of Sorghum

Malting is an important industrial product with a huge market outlet. Sorghum grain carries a numerous and variable, microbial population that mainly consists of bacteria, yeasts, and filamentous fungi. Sorghum malt is heavily reliant on chemical control of moulds and coliforms. This research aimed at investigating ways of improving malt quality and safety, using starter cultures of lactic acid bacteria and yeast, during the steeping stage of malting. All the steep treatments contained a sizeable population of moulds, greater than 4logcfu/mL, at 0hrs of steeping. A 3Log decrease was recorded in the steep treatment containing only single culture of Lactobacillus plantarum All the steeping treatments achieved varying levels of anti-nutrient reduction. The Lactobacillus plantarum CLB8 steep reduced the phytate level by as much as 47% when compared to the phytate level in sorghum grain. The combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiaeCYT1 reduced the phytate content by as much as 40% when compared to the sorghum grain without treatment. When compared to the control steep, the Lactobacillus plantarum CLB8 steep improved the anti-nutrient degradation by 31%. The combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiae CYT1 reduced the phytate content by as much as 23% when compared with the control steep. The polyphenol content was reduced by about 46% in the Lactobacillus plantarum CLB8 steep and 29% in the combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiae CYT1 steep when compared to the polyphenol content in the whole sorghum grain. Only the Lactobacillus plantarum CLB8 steep had better polyphenol reduction than the control with a 9.6% reduction more than the control. It was concluded that lactic acid bacteria can be apply as a biological control organism in malting of grains.

Time series barley germination is predictable and associated with known seed dormancy loci

AbstractPreharvest sprouting (PHS) resistance is essential in malting barley (Hordeum vulgare L.) production to prevent damage caused by late season moisture but may be negatively correlated with malting quality traits. The germination percentage and germination rate (GI) in malting barley are measures of both PHS resistance and suitability for malting. Functional principal component analysis (FPCA) and logistic regression on time series spring malting barley GE and GI were performed to identify genetic regions associated with germination trait changes from 0 to 22 wk after maturity. Both analysis methods identified the SD1 and SD2 regions known to affect germination traits, as well as one novel locus on chromosome 6H at 473 Mbp. Several other associations were detected with a single analysis method. Genomic prediction (GP) was used in conjunction with the time series models to test GE and GI predictability over time. Germination traits of unobserved lines at unobserved times were predicted with high accuracy using ridge regression GP coupled with FPCA or logistic regression. The results demonstrate applicability of time series data analysis in determining genetics of germination trait changes in malting barley and that time series germination is predictable. Threshold traits calculated with these time series models, such as the after‐ripening time needed until a line achieves a GE of 95%, can be used as an estimate for dormancy duration, which will be useful in breeding for combined PHS resistance and malting quality.

Genetic variation among selected pure lines from Turkish barley landrace 'Tokak' in yield-related and malting quality traits

Aim of study: Improvement of barley cultivars for malting traits suffers from narrow genetic pool in barley for these traits. Landraces are resources that could be used for this purpose. The present study was conducted to determine the variation for malting quality traits within a Turkish barley landrace. Area of study: The study was undertaken in Tokat, a province in Black Sea Region of Turkey. Material and methods: Twenty-five diverse lines, out of 42 unique genotypes previously identified in ‘Tokak’ landrace (PI 470281) based on DNA markers, were evaluated for malting quality traits along with the malting barley cv. ‘Tokak 157/37’ in four field trials. Thousand-seed weight, test weight, grain yield, lodging, malt extract percentage, diastatic power, alpha amylase and malt beta glucanase activities, malt protein and starch contents were determined. Main results: Principal component analysis of malting quality traits revealed that thousand-seed weight, alpha amylase activity, beta glucanase activity and diastatic power were the most discriminatory traits for the lines. As the average of four trials, 15 of the 25 lines evaluated had higher grain yields and 10 of 25 lines had higher malt extract percentages than the standard cultivar ‘Tokak 157/37’. Malt extract was highest in Line 59 in all environments, and this line also had the highest values for beta glucanase activity and starch content. Line 215 had highest values for alpha amylase activity. Lines 59 and 215 clearly had superior malting quality. Research highlights: These lines could harbor novel alleles for these traits to be used in malting barley improvement.

Comparative proteomic analysis of different barley cultivars during seed germination

Malting quality is an important determinant of the barley grain value used in brewing. Malting process is an accurately controlled barley germination followed by kilning and is modified according to the characteristics of the barley variety. However, the genetic mechanism of malting difference among varieties is still not clear. The present study aims to analyze the mechanism of malting performance variance about the different cultivars, especially the Chinese barley Gan-7. We identified brewing performance variance of Gan-7, Copeland, Spartacus and determined the variation in proteomic profiles among these cultivars. 114 proteins with significant differences between cultivars were identified and the roles of differential expression proteins in malt quality discrimination were elucidated according to their putative functions. The differentially expressed proteins mainly related to genetic information processing and carbohydrate metabolism pathways. Among them, we find that the poor α-amylase activity of Gan-7 is related to the low abundance of α-amylase. The performance of Gan-7 may be partly attributed to the differentially expressed proteins involved in starch hydrolysis, PRs, hordoindoline, hordein, trypsin inhibitor processes. In the present study, only barley variety used for malting was considered, and this can explain the cultivar effect of malting. These results may provide clues for optimizing the malting process for Chinese domestic barley cultivars, especially Gan-7.

Methods for suppressing Fusarium infection during malting and their effect on malt quality

The incidence of Fusarium head blight (FHB) in cereal grains such as barley and wheat is of growing concern due to climate change threatening food safety. Further processing of cereals by malting provides an ideal environment for the growth of Fusarium, leading to food safety concerns due to the production of mycotoxins, production challenges with the negative effects to malt and beer qualities, and economic loss owing to the field yield reduction. To improve food safety and product quality, different methods of fungal control have been investigated and reported in the literature. Traditional methods to control fungal growth and mycotoxin production have included chemical and physical methods, but these treatments led to worsened malt properties, limiting their applicability to the brewing industry. Biological control methods have, therefore, attracted wide interest as alternative treatments due to their ability to limit Fusarium growth and mycotoxin production in malting cereals without toxic by-products, thus exhibiting promise for improving food safety. Various biological agents have been investigated and applied in malting and have shown the potential to suppress Fusarium spp. growth and mycotoxin production. These agents include several lactic acid bacterial (LAB) species and Geotrichum candidum. Another promising biocontrol agent for malting control is Pythium oligandrum, which has successfully limited Fusarium infection in other agricultural crops. The review outlines the Fusarium-control methods reported referenced for the brewing industry and the present prospects in biological control applications on the promise of P. oligandrum as a novel agent for malting.

QTL x environment modeling of malting barley preharvest sprouting.

HvMKK3 alleles are temperature sensitive and are major contributors to environmental stability of preharvest sprouting in barley. Preharvest sprouting (PHS) can severely damage barley (Hordeum vulgare L.) malting quality, but PHS resistance is often negatively correlated with malting quality. Seed dormancy is closely related to PHS. Increased temperature during grain fill can decrease seed dormancy in barley, but genetic components of seed dormancy temperature sensitivity are poorly understood. Six years of PHS data were used to fit quantitative trait locus (QTL) x environment mixed models incorporating marker data from seed dormancy genes HvAlaAT1, HvGA20ox1, and HvMKK3 and weather covariates in spring and winter two-row malting barley. Variation in winter barley PHS was best modeled by average temperature range during grain fill and spring barley PHS by total precipitation during grain fill. Average high temperature during grain fill also accurately modeled PHS for both datasets. A highly non-dormant HvMKK3 allele determined baseline PHS susceptibility and HvAlaAT1 interactions with multiple HvMKK3 alleles conferred environmental sensitivity. Polygenic variation for PHS within haplotype was detected. Residual genotype and QTL by environment interaction variance indicated additional environmental and genetic factors involved in PHS. These models provide insight into genotype and environmental regulation of barley seed dormancy, a method for PHS forecasting, and a tool for breeders to improve PHS resistance.

Winter Malting Barley Growth, Yield, and Quality following Leguminous Cover Crops in the Northeast United States

There is growing interest in malting barley (Hordeum vulgare L.) production in the Northeastern United States. This crop must meet high quality standards for malting but can command a high price if these quality thresholds are met. A two-year field experiment was conducted from 2015 to 2017 to evaluate the impact of two leguminous cover crops, sunn hemp (Crotalaria juncea L.) and crimson clover (Trifolium incarnatum L.), on subsequent winter malting barley production. Four cover crop treatments—sunn hemp (SH), crimson clover (CC), sunn hemp and crimson clover mixture (SH + CC), and no cover crop (NC)—were grown before planting barley at three seeding rates (300, 350, and 400 seeds m−2). SH and SH + CC produced significantly more biomass and residual nitrogen than the CC and NC treatments. Higher barley seeding rates led to higher seedling density and winter survival. However, the subsequent spring and summer barley growth metrics, yield, and malting quality were not different in any of the treatments. There is much left to investigate in determining the best malting barley production practices in the Northeastern United States, but these results show that winter malting barley can be successfully integrated into crop rotations with leguminous plants without negative impacts on barley growth, yield, and grain quality.

Using Malt Total Nitrogen (TN) as a Malt Quality Metric

Using Malt Total Nitrogen (TN) as a Malt Quality Metric