Changes in Barley Kernel Hardness and Malting Quality Caused by Microwave Irradiation

The effect of sowing date on grain protein, hordein fraction content and malting quality of two-rowed spring barley was investigated by using ten commercial cultivars with different grain protein content and the relationships among these traits were examined. The results showed that grain protein content and B hordein content increased as the sowing date postponed and were significantly affected by sowing date, while C and D hordein contents were less influenced by sowing date. There were significant differences in grain protein and hordein fraction content among the ten cultivars. The coefficient of variation of D hordein content was much larger than that of B and C hordein contents, suggesting its greater variation caused by different sowing dates. Beta-amylase activity and diastatic power were also significantly affected by sowing date, with malt extract being less affected. Significant differences in measured malt quality were found among the ten cultivars. Grain protein was significantly correlated with B hordein and malt extract positively and negatively, respectively. There was no significant correlation between beta-amylase activity or diastatic power and grain protein content. B hordein was negatively and significantly correlated with malt extract, but no significant correlations between C hordein, D hordein and malting quality traits.

Malting and brewing are major uses of barley (Hordeum vulgare L.) worldwide, utilizing 30–40% of the crop each year. A set of complex traits determines the quality of malted barley and its subsequent use for beer. Molecular genetics technology has increased our understanding of genetic control of the many malting and brewing quality traits, most of which are quantitatively inherited. The objective of this study was to further dissect and evaluate a known major malting quality quantitative trait locus (QTL) region of about 28 cM on chromosome 1 (7H). Molecular marker-assisted backcrossing was used to develop 39 isolines originating from a ‘Steptoe’ / ‘Morex’ cross. Morex, a 6–row malting type, was the donor parent and Steptoe, a 6–row feed type, was the recurrent parent. The isolines and parents were grown in four environments, and the grain was micro-malted and analyzed for malting quality traits. The effect of each Morex chromosome segment in the QTL target region was determined by composite interval mapping (CIM) and confirmed and refined by multiple interval mapping (MIM). One QTL was resolved for malt extract content, and two QTLs each were resolved for α-amylase activity, diastatic power, and malt β-glucan content. One additional putative malt extract QTL was detected at the plus border of the target region by CIM, but not confirmed by MIM. All QTLs were resolved to intervals of 2.0 to 6.4 cM by CIM, and to intervals of 2.0 cM or less by MIM. These results should facilitate marker-assisted selection in breeding improved malting barley cultivars.

Although environmental conditions during grain filling are often cited as the reason for decreases in malting quality of barley, little is actually known about the specific effects of different environmental conditions on grain yield and quality of barley. In the present study, an attempt was made to assess in the field the effects of short periods of high temperature (>35¦C), using portable chambers with thermostatically controlled electric heaters, on grain yield and quality of barley. Two experiments were carried out in 2 consecutive years, involving the malting barley cultivars Schooner (first year) and Parwan (second year). The treatments were (i) control (no chamber, no heating) during the whole grain-filling period, (ii) plots with chambers heated to ca. 40¦C for 6 h per day over 5 days starting 17 days after anthesis, and (iii) plots with non-heated chambers for 5 days from 17 days after anthesis. High temperature treatments reduced individual grain weight by 14% in Schooner and 25% in Parwan. There was a reduction in starch content and an increase in nitrogen content in the heat treatments compared to the control, but the G-glucan content was similar to the control. The resulting malt extract was reduced from 79 to 73% in Schooner and from 68.4 to 66.2% in Parwan in ,the heat stress treatment. The starch granule size distribution was also measured. Results indicate that decreases in grain dry matter were due to reductions in number rather than size of starch granules. It is concluded that high temperature reduced the amount of 'maltable' grain by reducing grain size and increasing the screening percentage, and also reduced malt extract by 3-7%, which represents a large decrease for the malting industry.

Barley malt quality analysis is essential for craft malt houses, commercial producers, and barley breeding programs, yet traditional methods are resource-intensive and time-consuming. We combined attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy with automated multivariate regression models to predict eight malt quality traits. Using super partial least-squares (sPLS) and super support vector regression (sSVR), quality metrics were evaluated using 460 barley lines from three U.S. locations. External validation coefficients of determination (Rv2) were the highest for barley protein (BP), soluble protein/total protein (S/T), and malt extract (ME). These values were respectively 0.946, 0.907, and 0.880 for sSVR and 0.942, 0.901, and 0.867 for sPLS. Average validation errors for ME, BP, and S/T were 1.3%, 4.6%, and 6.3%, respectively, for sSVR and 1.4%, 4.7%, and 6.5% for sPLS, respectively. Variable selection methods─binning, wavelet, and variance feature ranking (VFR)─were compared, with binning and wavelet techniques retaining information effectively even when measurements were reduced by 95%. The ratio of performance to deviation (RPD) values of BP, S/T, and ME models for sPLS to sSVR were 4.2 to 4.3, 3.2 to 3.3, and 2.7 to 2.9, respectively. These models provide an efficient, nondestructive alternative for rapid barley malt quality analysis, offering scalable tools for research and industry applications in barley breeding and malt production.

MacLeod, A. L., Langrell, D. E. and Edney, M. J. 2014. Comparison of harvest and export surveys of Canadian malting barley quality. Can. J. Plant Sci. 94: 587–592. The Canadian Grain Commission conducts an annual harvest survey to determine the quality of each year's malting barley crop. Throughout the year, quality testing is also performed on export shipments of malting barley as part of a quality monitoring program. The testing protocol includes barley quality parameters as well as micro-malting and malt quality analysis. In this study, results from the two surveys were compared over an 11-yr period. Overall, the harvest survey was a reliable predictor of the quality of barley exports. Barley quality was more closely correlated between the two surveys than malt quality. Several factors were identified which contributed to differences between the two survey programs.

A set of 92 genetic resources of spring barley split into groups according to the areas of origin was studied in terms of grain malting quality. The following malting parameters were monitored in this study: nitrogen content in barley grain, malt extract, relative extract at 45 °C, Kolbach index, diastatic power, apparent final attenuation, friability, β-glucans in wort, haze of wort measured at the angles of 15° and 90°. In the studied set, the largest variability was found in the haze of wort (90°), the smallest in the apparent final attenuation. The optimal values of the extract content in the malt dry matter according to the malting quality index were only detected in the genotypes originating from Europe. The group of the genetic resources from South America and Australia, together with the genotypes from the Middle East and Africa, differed statistically significantly in the values of the Kolbach index from other groups. The two-row genotypes differed statistically significantly in the values of the malt extract content, relative extract at 45 °C, Kolbach index, diastatic power, friability and β-glucan content in wort. Although the European and non-European groups differed in a number of traits, the non-European groups also included genetic resources that in their malting parameters approached or equaled the European malting varieties (such as Psaknon). In this study, several significant correlations were found; the strongest correlations were between friability and malt extract (r = 0.85), friability and Kolbach index (r = 0.84).

Effects of sulphur on yield and malting quality of barley

This investigation presents a holistic and comprehensive assessment of the stepwise changes in barley quality during the malting process for multiple batches of two Australian malting varieties (Buloke and Gairdner), in two modern, commercial scale pneumatic malthouses. The study sought to analyse and compare malting plant and variety with respect to basic changes in malt quality for protein (total protein and free amino nitrogen), fermentability (apparent attenuation limit and diastatic power), extract yield, along with filtration indicators (lautering efficiency, viscosity and β-glucan). Overall, comparing the two malt plants, it was observed that although malt batches and varieties followed different malting pathways, the finished and kilned malt was of satisfactory quality in terms of FAN, viscosity, friability, fermentability and extract. © 2020 The Institute of Brewing & Distilling

Correlations between all possible pairs of 8 agronomic and 9 malting quality traits were calculated from a population of 102 random lines of the F4 generation from an intervarietal malting barley cross. A strong positive correlation between head erectness and lodging should prove useful for selection purposes, since head erectness can be determined in th absence of differential lodging. Plump barley was negatively correlated with barley color and positively with malt extract. Extract was positively correlated with bushel weight and the wort N/malt N ratio. Beta amylase was positively associated with diastatic power and the beta/alpha ratio. Diastatic power and beta/alpha ratio were positively correlated. Alpha amylase was positively correlated with the wort N/malt N ratio. Alpha and beta amylases were not correlated, indicating that these two traits are independently inherited.Grain yield exhibited no really large correlations with any of the other traits, indicating that it should be possible to select for most quality traits without seriously reducing yield.Correlations among three malting quality and two agronomic traits were compared with published reports by other workers.

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.

The total 43 Slovak spring barley genotypes with a year of cultivation or registration from 1938 to 2009 were evaluated in terms of selected parameters like protein, starch, and β-glucan contents. Collection of genetic resources consisted of barley malting qualities such as elite - A, standard quality - B, no malting quality - C and five genotypes of unspecified malting quality. Significant (P < 0.01) influence of genotype and environmental conditions (years) and also genotype × year interaction on protein, starch, and β-glucan content in the barley grain were detected. The highest average protein content was observed in genotypes from the group with undetermined malting quality. The protein and β-glucan contents in older genotypes were higher in comparison with more recent genotypes. The average starch content in both older and modern genotypes in the studied set was nearly identical, which confirms a high quality of the older malting varieties. According to malting quality groups, the highest average value of β-glucan content was in the group of no malting quality (C) and the lowest in the group of best malting quality (A), which is in correspondence with barley malting quality requirements. In individual years differences in the β-glucan content were found among genotypes. Despite the atypical years, good sources of β-glucan were found out along with modern genotypes such as Cyril and older genotypes such as Orbit and Vladan, but also historically old genotypes were created in the year 1946 such as Diosecký 802 and Slovenský Dunajský trh. Our study has confirmed that these genotypes are donors of not only significant agronomic traits but also qualitative properties, usable in the food industry.

The Hagberg Falling Number measurement, widely used in the milling industry for assessing the baking quality of wheat flour, has been modified and used as a rapid mashing technique to assess malt quality. Barley Malt flour is mixed with cold mashing liquor containing 0.1% calcium chloride and 15 mM beta-mercapto-ethanol. The slurry is heated and mixed by the Falling Number apparatus, and the starch is gelatinized. After one minute of heating/mixing the stirring rods are raised and released. As the gelatinized starch is hydrolysed by amylases, the viscosity of the slurry decreases allowing the stirring rods to fall. The time taken for these rods to fall a fixed distance is called the Falling Number. A relationship has been determined between the Falling Number obtained for a malt and the quality of the malt. Poor quality malts had a high Falling Number (e.g. >200s) whilst good malts had a low Falling Number (e.g. <150s). The correlation coefficient between Falling Number and Hot Water Extract (IOB coarse grind) was −0.89, and between Falling Number and Friability was −0.96. These good correlations indicate the measurement was influenced by the degree of endosperm modification. Being a mashing technique, however, the Falling Number was also influenced by other factors which influence mashing such as enzyme complement and water binding. This technique has the potential to measure malt quality using a commercial apparatus more rapidly than present malt analyses. No significant relationship could be determined between the Falling Number and the malting quality of barley.

After the harvest 2023, three varieties were registered in the Slovak Republic after three years of testing: the spring barley variety LG Rhapsody, the two-row winter barley variety Claudia, and the six-row winter barley variety MH Irén. The malting quality was determined for the varieties LG Rhapsody and Claudia. LG Rhapsody gave extract in malt dry matter of 83.2%. Proteolytic modification of this variety was high (Kolbach index 52.3%). The diastatic power (343 WK), the quality of the sweet wort (apparent final attenuation 82.1%), and the cytolytic modification (friability 94% and β-glucan content 60 mg/l) were at an optimal level. In all cases, the variety gave a clear sweet wort. The winter two-row barley variety Claudia gave a sweet wort with an extract of 81.5%. Kolbach index (46.2%) and diastatic power (508 WK) were at optimal levels. The quality of the sweet wort (apparent final attenuation 80.5%) and the cytolytic modification (friability 83% and β-glucan content of the wort 169 mg/l) were at an average level.

Malting barley is of high economic and scientific importance. Determining barley grains that are suitable for malting involves measuring malting quality, which is an expensive and complex process. In order to decrease the cost of phenotyping and accelerate the process of developing superior malting barley cultivars, markers for marker-assisted breeding are needed. In this study, we identified quantitative trait loci (QTLs) for malting traits in a Stellar/01Ab8219 F6:8 recombinant inbred line population grown at Aberdeen and Tetonia, Idaho, USA in 2009 and 2010. We identified QTLs associated with malt extract (ME), wort protein, soluble/total protein (S/T), diastatic power (DP), alpha-amylase, beta-glucan (BG) and free amino nitrogen (FAN) at a logarithm of odds score ≥2.5 using a high-density genetic map produced by merging Diversity Arrays Technology markers with the current single nucleotide polymorphism map. Novel QTLs were identified for DP and FAN on chromosome 5H, S/T on 6H, and BG and ME on 7H. Dissection of the genetic regions associated with malting traits suggests the involvement of multiple molecular pathways. The resulting molecular markers may prove useful for barley improvement.

The rapid growth in the craft brewing industry is increasing the demand for winter barley production. Little recent research exists on producing winter barley for malting in the lower Midwestern United States, with a lack of understanding how previous legumes crops grown in rotation with winter barley interact with nitrogen (N) fertilization rates to affect grain yield and malting quality. To investigate these topics, a preliminary, 1‐year study was conducted in Missouri, USA, to test how growing soybean, a common rotational crop, and sunn hemp, a specialty forage crop, prior to winter barley, as well as two fall N fertilization rates (22.4 and 44.8 kg N ha−1), affected barley grain yield. Barley grain yield was unaffected by the previous legume crop choice or the fall N fertilization rate, suggesting that either crop provided adequate residual N to the succeeding barley crop. Additionally, malting quality was analyzed from representative grain samples to reveal adequate levels suitable for use in the craft brewing industry. This study's results reveal preliminary data supporting winter barley production in the lower Midwestern United States, with an indication that previously grown legume crops impact crop yield greater than fall N fertilizer rate.