Barleys Grown as Cultivar Mixtures Compared with Blends Made Before and After Malting,for Effects on Malting Performance

Four barley cultivars were grown in replicated trials at three sites in Scotland in 2000, both as pure stands and in all four possible three‐component mixtures. After harvest, some grain from the pure stands was used to synthesise four blends of three component varieties. Grain from the pure stands, the mixtures and the blends was malted and all samples were assessed for total β‐glucan content. At two of the sites, field grown mixtures were shown to have lower malt β‐glucan than blends made prior to malting, although their grain β‐glucan contents had not been significantly different from the means of the component varieties. At the other site, the mixtures had higher levels of soluble nitrogen than the blends or the means of their component cultivars although, significant differences had not occurred in grain nitrogen contents. Three component blends were also made from the malted grain of the pure stands and hot water extracts were measured on all samples including the blends made before and after malting. There were considerable differences between sites and also between mixtures, blends and the mean of the mixture components when assessed separately. At all sites and for all varietal combinations, field grown mixtures were shown to be equal or superior to blends made after harvesting, in addition to frequently exceeding the mean of their components. It was concluded that the advantages, in β‐glucan or protein modification, associated with mixtures resulted from interactions between components in the growing environment and that interactions in the malting and mashing environments had little if any effect.     

THE EFFECT OF CULTIVAR MIXTURES ON MALTING QUALITY IN WINTER BARLEY

A range of winter barley cultivars was grown, either as pure stands or as components of mixtures, in a trial in 1995–96. For malting quality characters, mean values of mixtures did not differ from mean values of the appropriate monocultures, except for decreases in homogeneity, as determined by a fluorescence test of cell wall modification. When disease pressure was modified by fungicide, hot water extract was not significantly altered, although this may have been due to the restriction of malting to grain retained by a 2.5 mm sieve. One mixture, comprised of three related winter malting cultivars, gave higher hot water extracts than its components, as pure stands, with no adverse effects on homogeneity. This was not simply attributable to lower grain nitrogen content .     

Influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing

BACKGROUND: This paper presents a multivariate approach to investigate the influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing. Four spring and two winter barley varieties were grown in one location in southern Europe. Moreover, one of the spring varieties was infested with sunn pest, in order to study the effects of this pest on malting quality, and subjected to different nitrogen fertilisation timing regimes. The samples were micromalted, mashed, brewed and analysed. RESULTS: The data showed that even though the two winter barleys seemed to be the best regarding their physical appearance (sieving fraction I + II > 82%), this superiority was not confirmed in the malt samples, which showed low values of Hartong extract (27.1%) and high values of pH (6.07–6.11) and β‐glucan content (12.5–13.2 g kg^?1), resulting in low‐quality beers. The barley sample subjected to postponed fertilisation had a total nitrogen content (19.5 g kg^?1 dry matter) exceeding the specification for malting barley and gave a beer with a low content of free amino nitrogen (47 mg L^?1) and high values of viscosity (1.99 cP) and β‐glucan content (533 mg L^?1). The beer obtained from the barley sample subjected to pest attack had good quality parameters. CONCLUSION: All spring barleys gave well‐modified malts and consequently beers of higher quality than the winter barleys. Moreover, postponed fertilisation was negatively related to the quality of the final beer, and sunn pest infestation did not induce important economic losses in the beer production chain. Copyright © 2010 Society of Chemical Industry     

Effects of seeding rate, nitrogen rate and cultivar on barley malt quality

BACKGROUND: Crop management tools have been shown to affect barley kernel size and grain protein content, but the direct effect on malt quality is not well understood. The present study investigated the effect of seeding rate, nitrogen fertilisation and cultivar on malt quality. RESULTS: Higher seeding rates produced barley with less grain protein and smaller, more uniformly sized kernels. The small, uniformly sized kernels modified more completely, leading to malt with higher extract and lower wort β‐glucan than malt from low‐seeding‐rate barley. Increasing rates of nitrogen fertilisation caused grain protein levels to increase, which limited endosperm modification and reduced malt extract levels. AC Metcalfe showed better modification and higher malt extract than CDC Copeland, but CDC Copeland had better protein modification at higher fertilisation rates, which resulted in less reduction of malt extract as nitrogen rate increased. CONCLUSION: Higher seeding rates reduced kernel size and grain protein levels without compromising malt extract owing to better endosperm modification of the more uniformly sized kernels. Negative effects of higher nitrogen rates on malt quality can be reduced through development of cultivars with improved ability to modify protein during malting. © 2012 Her Majesty the Queen in Right of Canada     

Analysing the contribution of component cultivars and cultivar combinations to malting quality,yield and disease in complex mixtures

BACKGROUND: Mixtures of cereal cultivars grown together generally enhance yield and reduce disease but end‐users will not accept them for quality uses. Some combinations with very different quality may be problematic, others complementary. The common origin of Maris Otter for quality in winter barley may enable the benefits of complex mixtures to be exploited without quality compromises. RESULTS: Seven winter barley cultivar monocultures and all their equal proportion mixtures were trialled and data analysed by ANOVA, REML and principal component analyses to determine the contribution of particular varieties or combinations to crop performance. Agronomic yield was positively correlated with component number. Pipkin contributed negatively to thousand grain weight (TGW), but positively to several quality traits; Gleam negatively to the same quality traits but strongly positively to yield; and Melanie combined strong yield and TGW characteristics with neutral quality traits. Interactions in mixtures with Maris Otter, from which most of the cultivars are likely to derive some of their quality traits, were less apparent for quality than for yield. CONCLUSIONS: Complex mixtures gave yield benefits generally without compromising quality, and analysis methods were developed to identify the beneficial or negative effects of component cultivars on malting quality traits, thereby providing data for optimising mixtures design. Copyright © 2008 Society of Chemical Industry     

MALT PROCESSING STABILITY OF BARLEY CULTIVARS — A STATISTICAL ANALYSIS

This paper presents a simple statistical analysis of malting process stability of barley cultivars grown for three years in the Mississippi Valley Six-rowed Uniform Barley Nursery and in the Western United States Two-rowed Uniform Barley Nursery. The effects of variety, location, and year on barley and malt quality were investigated. First, the Duncan Multiple Range Test was used to determine whether there were any varietal, location and year differences in barley and malt properties. The effects of variety, location, and year on various characteristics were further studied by comparing differences between extremes for the two-rowed and six-rowed barleys. Second, correlations between various properties were determined by calculating simple correlation coefficients. Barley nitrogen is the single most important parameter which affects extensively the processing characteristics of barley in malting and brewing, so the partial correlation coefficients, independent of total barley nitrogen, also were calculated. Third, the effects of variety, location, year, variety × location, variety × year, and location × year, were tested with variety × location × year as the estimate of error for each of the barley and malting properties. The stability model was designed to evaluate stability of all barley and malt properties. Based on the principle of regression analysis, the stability was measured by regression coefficient and the varietal mean of each barley and malting property. Stability (over years and locations) for kernel weight was significantly higher in the new than in the old cultivars. Improvements in stabilities of total extract and fine-coarse grind extract were greater and more consistent for the six-rowed than for the two-rowed barley malts. This reflects, presumably, the generally more satisfactory total extract and fine-coarse grind extract in the two-rowed barley malts than in the six-rowed barley malts.     

Micromalting triticale: Optimising processing conditions

Small-scale trials were carried out to optimise the conditions for micromalting triticale grain, using three varieties grown in the UK. Compared with barley, triticale grains required short steeping periods with a short air rest. They malted rapidly, and produced malts with high hot water extracts after 4 or 5 days' germination. Applications of gibberellic acid and potassium bromate during malting significantly altered the qualities of malts. Gibberellic acid increased hot water extracts, soluble nitrogen levels and malting losses. When the additives were used in combination, high hot water extracts were obtained and malting losses were reduced relative to controls, but unexpectedly the level of total soluble nitrogen was elevated and did not significantly differ from that obtained using gibberellic acid alone. Both additives usefully reduced wort viscosities, which were unacceptably high by barley malt brewing standards. Wort separation from small-scale mashes was slow.     

Variation across environments in patterns of water uptake and endosperm modification in barley varieties and variety mixtures

The malting barley varieties Chalice, Chariot, Optic and Prisma and all four three‐component mixtures derived from them were grown at three sites in eastern Scotland in 2000. Following harvest, malting samples were obtained for each trial entry from grain retained by a 2.5 mm sieve. Water uptake during the steeping phase of malting was determined on all samples at two of the sites. Of the varieties, Chariot was shown to have more extensive and also, at one site, more even hydration than the other varieties, whereas the mixtures were generally similar to the other three varieties in water uptake. Malt samples were tested for cell wall modification using a fluorescence method that assessed individual grains, so enabling both homogeneity and extent of modification to be calculated. There were significant differences between genotypes and between sites, with Chariot and Chalice showing poor modification at one site, which led to reduced levels of hot water extract. The variety Prisma had a lower level of predicted spirit yield at another site, possibly owing to over‐modification, and Optic was the only variety to give consistently high spirit yield at all three sites, despite considerable variations in levels of modification. The mixtures had better consistency in their malting results than the varieties, with the exception of Optic, and also performed well at sites where modification was sub‐optimal. Differences in spirit yield were greater between sites than between varieties, indicating that genotypic constitution may not always be a reliable predictor of phenotypic expression of malting quality. Copyright © 2006 Society of Chemical Industry     

VARIATION IN A BARLEY COLLECTION FOR ENDOSPERM ATTRIBUTES THAT RELATE TO MALTING QUALITY

Éstimates of grain hardness from measurements of milling energy were made on four hundred and eighty barley cultivars. The same cultivars were also subjected to an infra-red analysis used to predict soluble β-glucan and nitrogen contents. The results demonstrated variation for these endosperm characters, with eighteen cultivars having a lower milling energy, and more than a hundred cultivars with a lower soluble β-glucan content than Gerkra, a barley with good malting quality. Of these, nine cultivars were lower for both characteristics. Information about this variation is, therefore, potentially useful when breeding for malting quality.     

Floatation,a Bulk-Selection Method for Breeders which Permits the Selection of Faster Modifying Barley Grains

We have confirmed that floatation in salt solutions can be used to separate less-dense, more mealy, lower nitrogen-containing barley from more dense barley with less good malting quality having more steely grains and higher nitrogen contents. This gives breeders a useful tool for mass-selecting barley with potentially favourable characteristics for malting. We have now shown that green malt can be fractionated by floatation on sucrose solutions into fractions the least dense of which contains grains which are the most completely modified. This allows grains that have malted well to be selected. Using this novel technique it has been possible to substantially enrich fractions with green malt corns of the better quality malting variety when mixtures of a good and a less-good malting barley had been micromalted. The green malt fractions can be grown on to maturity. This technique gives breeders a powerful mass-selection tool for enriching their genetically mixed breeding lines with strains of better malting quality. This approach should be particularly powerful if applied several times in successive generations. The best results are likely to be obtained by fractionating the barley, collecting the lightest material, micromalting it and then collecting the lightest fraction of the green malt for further propagation.     

Barley and Malt Proteins and Proteinases: III. A Simple Method for Estimating the Combined Actions of Malt Proteinases and the Extent of Protein Degradation during Malting

The activities of barley and malt proteinases have been measured using haemoglobin and the highly degradable barley protein fraction (HDBPF) in malting and feed barley varieties. In conjunction, the barley and malt total protein and its components: hordein, glutelin, soluble proteins and free amino nitrogen (FAN) as well as Kolbach index were investigated. The comparative analysis of results revealed that the general grain modification index of Kolbach (KI), which was higher in malting varieties, was much more strongly associated with the levels of hordein degraded during malting than any other parameter investigated. The KI levels were also correlated with the increase in the levels of FAN, but not with the increase in the levels of soluble protein or changes in the glutelin component. The changes in total proteinase activity were low and cannot account for the increase in KI or the degraded hordein. The levels of total proteinase activity in both feed and malting barley varieties were similar. The results suggest that estimation of the levels of degraded hordein, during malting, is a sensitive indicator of the total proteolytic action of proteinases as well as the degradability of the reserve proteins. Therefore, we recommend measuring the amounts of hordein degraded during malting for the assessment of the impacts of grain protein and proteinases on malting barley quality of different varieties, in addition to KI and FAN.     

COMPARATIVE STUDIES OF THE β-D-GLUCAN RELEASED INTO SORGHUM AND BARLEY WORTS

Worts prepared from two cultivars of Nigerian grown sorghum six day melts — LI87 end SK5912 had β-D-glucan levels off five to seven times more than that of proctor barley. In contrast to barley, malting of the sorghums results in the release off more β-D-glucan into wort. Apparently, this is due to increasing levels of β-glucan solubilase and (1→3)-β-glucanase during malting with no significant (1→3, 1→4)-β-glucanase activity.     

Effects of Genotype and Environment on Malt β-Glucanase Activity

Fifteen genotypes of barley grown in two different locations (Gönen and Besni) were used in this study. The malting characteristics and β-glucanase activities of their malts were determined. Although, malt β-glucanase activities of the samples grown in the Besni location were much higher than those of Gönen samples, the malting quality of the samples from both locations were comparable. The results indicate that both genotype and environment affected β-glucanase activity with a more pronounced effect of the latter.     

Effects of Malting on Phase Transition Behaviour of Starch in Barley Cultivars with Varying Amylose Content

The effect of malting on the phase transition behaviour of starch in barley cultivars with varying amylose content was studied using differential scanning calorimetry (DSC). A slight elevation in the melting transition temperature of amylopectin of malt starch and a pronounced decrease in gelatinisation enthalpy for both malt flour and starch were observed for all samples. Evidence was provided from the calorimetric data and the ¹³C CP/MAS NMR spectra that starch-lipid interactions in the form of complexes are enhanced as a result of malting. There was also a large reduction in the melting transition temperature of the amylose-lipid complexes of malt flours, presumably due to partial degradation of amylose in malt, whereas the transition enthalpies of the complexes increased for both malt flours and starches. The DSC transition characteristics of the three good malting barley cultivars grown in different locations and of their respective malts showed that environmental conditions during starch synthesis have a great influence on starch granule organization, and thereby affect the thermal stability of amylopectin crystallites.     

Malting Behaviour of Barleys Grown in Canada and Spain as Related to Hordein and Enzyme Content

To continue our effort to analyse the genetic (varietal) and environmental (sites and years) effects on malting quality of barley, we have field‐tested four barley varieties, two‐ and six‐rowed, European and North American, in Spain and Canada in 1998 and 1999. The Spanish trials were autumn‐sown whereas the Canadian ones were spring‐sown. Barley grain was analysed for total protein and hordein contents and micromalted. Canadian‐grown barleys had significantly lower contents of grain protein and all‐three hordein fractions than the Spanish ones. They also had lower malt respiratory losses, wort β‐glucan and viscosity but lower fine‐ and coarse‐ground malt extract yield, friability, free amino nitrogen, Kolbach index, α‐amylase and diastatic power. In other words, the Canadian‐grown barleys, despite showing lower protein and hordein contents, produced malt of inferior quality than their Spanish counterparts, which, overall, produced higher quantities of degrading enzymes (amylolytic, proteolytic and cytolytic) during germination, thus being able to attain higher extract yield levels.     

Genetic and environmental impact on protein profiles in barley and malt

Canadian barleys have higher protein content and better protein modification than Australian barleys. Protein and protein modification was investigated in two Australian and two Canadian barley varieties under different levels of nitrogen fertilisation. Mass spectrometry was used to analyse protein profiles in grain and malt to assess how genetic and environmental factors modified the proteins in grain and malt. The differences in grain protein between the Australian and Canadian varieties were mainly in the high molecular weight proteins, less in water soluble proteins and rarely in salt‐soluble proteins, while malt protein variations were observed in all three groups. Generally, Canadian varieties contained more proteins in grain, but less water soluble and salt soluble proteins in malt. Monitoring the protein modification during the malting indicated that more proteins were digested in Canadian varieties. Genetic factors were dominant for protein variation, although environment also affected the protein composition. Barley varieties growing in Canada generally contained slightly higher protein content, and nitrogen fertiliser influenced proteins in grain that ranged from 43,000 to 47,000 Da. The protein pattern of high fermentability and lower fermentability varieties mainly varied from 30,000 to 40,000 Da. © 2018 The Institute of Brewing & Distilling     

Japanese Barley Meets Australia: Quality Performance of Malting Barley Grown in Different Countries

The aim of this study is to establish whether it is possible to select malting barley showing high quality under Australian conditions on the basis of malting quality data from the crop of the same genotype grown at a breeding station in Japan. Two approaches were taken to analyse the data obtained over several years. The first was a bivariate mixed model used to obtain variety estimates for the various quality traits of interest. The second approach used a univariate mixed model to determine the correlation between the same genotype grown in Australia and Japan, as well as the correlation between the same genotype grown at trial sites within a country. The first analysis found that nitrogen was related to most malting quality traits except for viscosity. The second analysis showed that the performance in Australia and Japan is similar for all malting quality traits. It may therefore be possible to select barley showing high malting quality under Australian conditions on the basis of malting quality data from the Japanese crop of the same genotype.     

Genotypic and environmental variation in phytic acid content and its relation to protein content and malt quality in barley

Phytic acid or phytate is a chelating agent, which is involved in binding minerals (such as K⁺, Ca²⁺, Zn²⁺, Fe²⁺, etc.) and making them unavailable for dietary absorption. It is also involved in forming complexes with protein, making protein less soluble, and affecting enzymatic degradation, gastric absorption, and malting processes. The phytic acid and protein contents of barley grains are influenced by genetic and environmental factors. This study investigated differences in phytic acid and protein contents in grains of 100 barley (Hordeum vulgare L.) genotypes or cultivars. Eight barley cultivars were selected and grown at seven locations for two years to study the effects of genotypic and environmental factors on phytic acid content (PAC) and its relation to malt quality. The phytic acid contents of 100 barley genotypes ranged from 3.85 mg g⁻¹ to 9.85 mg g⁻¹, with a mean of 7.01 mg g⁻¹. The effects of cultivars, locations, time and their interactions were highly significant, but the variation was mainly attributed to the environment (location and time). The correlation between grains phytic acid and protein content was significant and positive. Whereas, the correlation between grain phytic acid content and malt extract was significant and negative. The relationship between phytic acid and protein contents of barley is important as it affects the malting process, malt yield and quality, and final beer quality. Barley grain for malting and feed uses should have low phytic acid content.     

Changes in saccharide,amino acid and S‐methylmethionine content during malting of barley grown with different nitrogen and sulfur status

BACKGROUND: Changes in saccharide, amino acid and S‐methylmethionine (SMM) concentrations and enzyme activities during the malting of barley grown with different nitrogen (N) and sulfur (S) supplementation were investigated in order to clarify their relationship with N and S fertiliser levels. RESULTS: Concentrations of N and S in barley grain were significantly increased by the addition of N to the culture soil. Application of N decreased the starch concentration in grain. On the other hand, higher N fertilisation increased the β‐glucan concentration in grain and malt, thus decreasing the accessibility of β‐glucanase to its substrates. Proteolytic enzyme activity was significantly higher in the absence (?N treatment) than in the presence (+N treatment) of N fertiliser, making the concentration of the majority of amino acids in malt slightly higher in the ? N treatment. SMM was synthesised in grain after imbibition, and application of N increased the SMM content in malt. CONCLUSION: Although SMM can be controlled to a certain extent during kilning, a balanced supply of N and S during cultivation can also be helpful for the production of malt with lower SMM concentration. Adequate soil management is desirable to maintain the balance between good agronomic performance and high malt quality. Copyright © 2010 Society of Chemical Industry     

Investigation of Protein Composition of Barley by Gel Electrophoresis and MALDI Mass Spectrometry with Regard to the Malting and Brewing Process

The protein composition of barley partly determines its quality in terms of malting and brewing. For this reason, the water‐soluble proteins of two different barley cultivars were investigated by gel electrophoresis and matrix‐assisted laser desorption/ionization mass spectrometry. Mass spectra were obtained directly from barley extracts by using three matrices. According to the quality of the measured spectra, it was possible to establish which matrix was the most suitable for the analysis of water‐soluble proteins from barley. We found that the protein patterns did not differ significantly between Jersey and Tolar varieties. However, our results showed the influence of the malting process on the posttranslational modification of some water‐soluble barley proteins. These proteins also survive the brewing process and they are very important for the formation and stability of beer foam. Several barley proteins were also identified by proteomic analysis.