Evaluation of malting quality of spring barley genetic resources from different regions of origin

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.

This study presents the results of malting quality and agronomic characters obtained within state varietal testsof malting barley in the Slovak Republic. After the harvest of 2019, new spring malting barley varieties of Avus,Bernet, and LG Nabuco were registered. The spring barley varieties provided malt with extract content above 83%. All varieties degraded nitrogenous substances easily. The values of Kolbach index ranged from 47.5 to 49.5%. Diastatic power was at the optimal level and moved above the level of 300 WK un. in all the studied varieties. Also, cell wall degradation was optimal and friability was higher than 90%. Content of β-glucans in wort reached favourable values (72–141 mg/l). Quality of wort characterized by apparent final attenuation was at the above average value to the optimal level (81–81.8%) in the studied spring barley varieties.

The relationship of limit dextrinase, limit dextrinase inhibitor and malt quality parameters in barley and their genetic analysis

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.

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.

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.

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.

After completing the state varietal tests, the spring barley malting varieties Chimbon, Laureate and LG Aurus, and were registered in the Slovak Republic. Extract content in dry matter in the studied varieties was high and moved in the scope of 83.1 – 83.5 %. The varieties had strong proteolytic modification (Kolbach index 49.5 – 50.7 %). Amylolytic and cytolytic modification was at the optimal level. Wort quality was optimal (apparent final attenuation 81.5 – 82.2 %). The studied varieties gave clear wort, with the exception of the variety Accordine with the weakly opalizing wort.

To date, relatively few studies analyzed the motherhood penalty as experienced by immigrant women. The principal objective of this research is to establish whether the negative effect of motherhood on wages is higher for immigrants than it is for the native population; and how this effect may vary across different immigrant regions of origin. Using data from the Enquête Revenus Fiscaux et Sociaux from 2009 to 2012 (INSEE, 2009–2012)1, a series of linear regression models were calculated to examine whether the effect of motherhood on wages differs for immigrant women and native women; and to what extent this effect varies across different immigrant origin groups. Specifically, this study explores the effect of motherhood on immigrant labor market integration in France from three regions of origin, as compared to native French women: immigrants from sub-Saharan Africa, the Maghreb (Algeria, Tunisia, and Morocco), and from European countries (each and every region of origin is considered separately in comparison to native French women). The results revealed substantial differences in the motherhood penalty between the different regions of origin and assert the existence of an especially pronounced motherhood penalty for mothers from the Maghreb. Given the gap in the research with regards to the cost of motherhood for immigrants in the labor market of the host country, this research sheds light on specific mechanisms influencing the integration patterns of immigrant women. Moreover, by choosing France, which is one of the main immigration destinations in Europe, and a country where the motherhood penalty for the native population is almost non-existent, this study provides a new perspective on the intersection of motherhood, immigration, and region of origin in the immigrants' labor-market integration process.

Pilot (50 litre) and small scale (700 mL) brewing trials conducted using, similar brewing protocols with 25 different malts, indicated that differences in malt quality influenced foam stability (Rudin head retention value) by up to 24%. In addition to conventional measures of malt quality, enzyme-linked immunosorbent assays (ELISA) were used to measure the level of the putative foam-positive proteins, BSZ4 (protein Z4), BSZ7 (protein Z7), BSZ7b and lipid transfer protein 1 (LTP1). Regression analysis performed on the combined pilot and small scale data sets identified that malt BSZ4, wort β-glucan and wort viscosity, and beer protein, β-glucan and arabinoxylan were positively correlated with foam stability, while malt Kolbach index (KI), and beer FAN were negatively correlated with foam stability. Potentially foam-positive proteins such as BSZ7 and LTP1 were not correlated with foam stability. The negative correlation of BSZ4 level with KI suggested an additional role for BSZ4 in influencing protein modification. Step-wise multiple regression indicated that up to 82% of the variation in foam stability could be predicted from the malt and beer characteristics measured, demonstrating that there are a number of inter related malt derived factors that influence beer foam stability.

Two aspects concerning quality test in relation to AA (alpha-amylase activity) in malt were investigated for the breeding of malting barley using 11 to 36 cultivars and superior lines of barley as materials. In the first place, a new simplified method was tested for analysing AA of many small scale samples in practical breeding. The method was a modification of the BANASIK method (1971), and in the modified method, the procedure for heating-inactivation of beta-amylase in the sample solution was automated and the centrifugation of the sample solution after heating-inactivation of beta-amylase was omitted. As a result, the whole analysis could be performed with an Auto-Analyser. The data obtained with this method were closely correlated with those obtained with the standard ASBC method. Secondly, environmental conditions affecting AA in malt and interrelations between AA and the other malt quality characters were investigated. The years of harvest and the locations were selected as experimental factors representing the crop cultivation environment, and malting procedures (sample scale fcr malting) were selected as those relating to the malting conditions. The results of statistical analysis suggested that the quality tests in relation to AA might be used for selection in practical breeding but were somewhat difficult to evaluate as compared with DP (diastatic power) tests since AA was more liable to vary with environmental conditions. AA showed a high positive or negative correlation with soluble nitrogen content (SN), Kolbach index (KI), malt yield (MY) and wort colour (WC). Comparison between AA and DP led to the conclusion that the AA test should be performed independently of the DP test.

Malting quality of feed and malting barley treated by microwave irradiation for 0, 4, 5, 8, 10, 15, 20, and 25 sec was evaluated. Microwave irradiation periods longer than 10 sec increased kernel temperature higher than the physiological limit and significantly affected germination. With 4 sec of microwave irradiation, barley kernel hardness decreased and transformed into malt of good quality. The feed barley Adabella without treatment showed double the hardness (49.3 N) and Pastor Ortiz showed almost three times the hardness (59.8 N) of malting barley Esmeralda without treatment (23.7 N). With 8 sec of irradiation, kernel hardness increased. Irradiation of feed and malting barleys for 4 sec increased the extract content in malt. Barley kernel hardness showed a significantly high correlation with malt extract (r = −0.61; P ≤ 0.001). Extract viscosity decreased with microwave irradiation in all cases. Diastatic power and α-amylase were not affected by the treatments selected for this study. Microwave energy is a new alternative that allows modification of the kernel endosperm in a few seconds and increases the industrial quality of feed and malting barley.

In 2007 wort osmolyte concentration (OC) was introduced as a method of measuring malt quality. The OC (molar concentration of solutes) of a mash is predominantly due to the conversion of starch to sugars and storage proteins to smaller nitrogenous compounds. Malt extract (ME) (mass of material in wort) has been used since the 1700’s as a measure for malt quality. Here we compare OC and ME to wort sugar concentrations in lines from three U.S. barley breeding programs. Lines were malted using standard protocols. Worts were analyzed for OC with a vapor pressure osmometer, ME by the ASBC Method, and sugars by pulsed amperometric detection of HPLC separated sugars. Correlations between OC and the combined molar concentrations of glucose, maltose, maltotriose, fructose and sucrose (TFS) for lines from breeding programs A, B, and C were (A) r = 0.930, P < 0.0001, (B) r = 0.625, P = 0.0014, and C) r = 0.667, P < 0.0001. Correlations between ME and TFS were (A) r = 0.408, P = 0.850, (B) r = 0.646, P = 0.0009, and (C) r = 0.081, P = 0.650. Correlations between OC and wort maltose were (A) r = 0.904, P= <0.0001, (B) r = 0.262, P = 0.2279, and (C) r = 0.105, P = 0.5534. Correlations between ME and wort maltose lines were (A) r = 0.009, P = 0.966, (B) r = 0.272, P = 0.2094, and (C) r= −0.011, P = 0.9504. This study indicates that OC is far superior to ME in the prediction of fermentable sugars in wort for some breeders’ lines and about equal to ME for others. These data also indicate that those lines that correlated well with fermentable sugars also correlated well with sucrose.

The effect of malting conditions on pearl millet malt quality was investigated. Grains were steeped for 24 h at different temperatures of 25, 30 and 35 °C and germinated at 25 °C for 24, 48 and 96 h. Generally, malt quality parameters such as malting loss, diastatic power, α- and β-amylase activity, free amino nitrogen (FAN), water extracts were significantly affected (P<0.05) by steeping temperature and germination time. Malting loss, FAN, hot water extract, diastatic power of the malt increased with increase in germination time as well as steeping temperature However germination time from 24 h onwards to 48 h exerted more pronounced enhancing effect on malting loss (140%), hot water extract (145%) and FAN (41%) of the malt. A steeping temperature of 30-35 °C and germination time of 4 days were found to be optimal for pearl millet malting as these conditions resulted in high diastatic power, α- and β-amylase activity, hot water extract, FAN and moderate malting loss.

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.