大麦醇溶蛋白与麦芽品质关系的研究进展

综述了近年来有关大麦醇溶蛋白和麦芽品质之间关系的研究进展,分析了醇溶蛋白电泳条带模型与麦芽品质之间的关系。多数研究结果表明,二者之间没有关系,但是采用聚类分析发现,醇溶蛋白电泳模型以麦芽品质为依据进行分类是有效的;有关D醇溶蛋白与麦芽品质之间关系的研究结论也不一致,有研究认为D醇溶蛋白与麦芽浸出率之间呈显著负相关,并且这种关系不受品种和年份的影响。但有人利用Hor3缺失的近等基因系进行的研究结果则并不支持这一观点。另据研究,由D醇溶蛋白和B醇溶蛋白组成的凝胶组分含量与麦芽品质呈负相关。     

The production and characterisation of Hor 3 null lines of barley provides new information on the relationship of D hordein to malting performance

Six pairs of near isogenic lines, differing in the presence of absence of D hordein, were produced in backgrounds with different B and C hordein alleles by introducing a Hor 3 null gene discovered in a barley germplasm collection. Biochemical and cytochemical studies were performed on the harvested and malted grains. Statistical comparisons of the composition of the grains and their malting performance revealed that neither presence or absence of D hordein, nor gel protein levels related to differences in malting performance of the different lines. However, differences in hordein amount and in the grain ultrastructural characteristics could be related to some differences in malting performance between and within some pairs of lines.     

Protein and hordein content in barley seeds as affected by nitrogen level and their relationship to beta-amylase activity

Two barley cultivars differing in grain size and protein content were used to investigate the effects of nitrogen nutrition, cultivar and their interaction on grain protein content, hordein content and beta-amylase activity and the relationship between hordein content and beta-amylase activity during in vitro spike culture. The content of protein and hordein fraction, and beta-amylase activity in barley grains increased as the nitrogen level in culture solution increased. Grain protein content was significantly affected by nitrogen treatment and cultivar, and there was no significant interaction between nitrogen treatment and cultivar. Hordein content and beta-amylase activity were significantly affected by nitrogen treatment and cultivar as well as their interaction. Beta-amylase activity was positively correlated with grain protein and hordein contents, and the ratio of hordein B:C was negatively correlated with total protein content and beta-amylase activity.     

Grain composition of Virginia winter barley and implications for use in feed,food, and biofuels production

Grain compositional components impacting barley (Hordeum vulgare L.) use in food, feed and fuel products, must be combined with improved agronomic traits to produce a commercially viable barley cultivar. Little current information is available on grain composition and variability among winter barley genotypes. This study was conducted to determine the variability among modern hulled and hulless winter barley genotypes in grain composition. Barley types varied significantly in grain and kernel weight, starch, beta-glucan, oil and ash content, but not in protein concentration. Hulless barley had significantly higher grain test weight and starch concentration than hulled and malting types, and significantly higher beta-glucan than malting barley. Hulless barley had significantly lower kernel weights, oil, and ash concentrations than hulled and malting types. Higher starch and lower fiber and ash in grain of hulless barley versus hulled feed or malting type barley are characteristics that increase hulless barley desirability. Selection for high starch concentration among all barley types is feasible and will facilitate development of barley cultivars better suited for use in feed, malt, and ethanol production.     

Relationship between specific weight of spring barley and malt quality

The assessment of malting barley to determine if it meets grain quality requirements is an integral step in ensuring an efficient malting process and a good quality malt output. Specific weight (SW) is an industry standard criterion, however links between SW and malting are not well understood. In this study the effect of a changing SW on malting was investigated. Samples were manipulated according to both grain size and weight, creating grain fractions with a range in SW. Prior to malting, grain quality traits were measured, and after malting, malt quality traits were examined. Increased SW resulted in a reduced number of whole, unmodified corns in malt, implying increased levels of modification. Specific weight correlated with both hot water malt extract (r = 0.82, P < 0.01) and predicted spirit yield (r = 0.84, P < 0.01), this highlights an increased malt output. Furthermore peak gelatinisation temperature of extracted starch from the malt correlated with both SW (r = 0.69, P < 0.05) and grain density (r = 0.65, P < 0.05). This could benefit malt efficiency by increased conversion of starch to fermentable sugars, but with the same energy input. The changes in SW and consequently malt output in this study are a result of changing grain density rather than packing efficiency.     

Influence of sulphur application on hordein composition and malting quality of barley (Hordeum vulgare L.) in northern European growing conditions

The influence of sulphur (S) application on yield formation, hordein composition and malting quality of 2-rowed spring barley (Hordeum vulgare L.) was studied in Nordic conditions for the first time. In a greenhouse experiment, S deficiency was indicated when 10 mg S/kg soil or less was available, by an increase in the malate:sulphate ratio in leaves. The contents of aspartic acid and cystine in grains increased and decreased, respectively. Also a substantial decrease of total hordein and the proportion of B hordein, and an increase in the proportion of C hordein were associated with S deficiency. The effect of S was further assessed in field experiments by applying N and S in four different combinations prior to sowing. No apparent S deficiency occurred in the field conditions based on the malate:sulphate and grain N:S ratio. However, in a site where the grain S content was slightly but significantly increased by S application, a change in hordein composition and malting quality was observed. Thus even in S-sufficient conditions, the end use quality of malting barley may be affected by S application.     

Relationships Between Barley Hordeins and Malting Quality in a Mutant of cv. Triumph I. Genotype by Environment Interaction of Hordein Content

The genetic (G), environmental (E) and G×E effects on total grain protein and hordein fractions, have been studied in a mutant (TL43) and its parent cultivar, the malting barley Triumph, in various seasons at Dundee (E Scotland) and Lleida (NE Spain). The grain protein content of TL43 was consistently about 2% higher than that of Triumph across environments. Differences in hordein composition were shown by SDS-PAGE electrophoresis. TL-43 had three B-hordein bands not present in Triumph which had a further three bands of the same hordein group not present in TL43. TL43 showed higher B-hordein content than Triumph in Scotland but lower in Spain, whereas the mutant showed consistently higher C- and D-hordein content than Triumph across environments, i.e. there was crossover G×E interaction for B-hordein and non-crossover for C- and D-hordein content. There were also differences in grain ultra-structure between the two lines, as TL43 showed a more dense protein matrix than Triumph, together with thinner pericarp, testa and aleurone layers. It was concluded that the mutation in TL43 had a significant effect on storage protein composition.     

啤酒大麦品种的蛋白质含量和环境变异研究

大麦是兼食用、饲用、酿造于一体的作物 ,蛋白质含量是各种用途大麦的重要品质性状。本研究在我国南方冬大麦区设置 8个试点 ,测定分析了 10个大麦品种在各试点种植两年的蛋白质含量。结果表明 ,蛋白质含量在品种间、地区间以及年度间均存在着显著差异 ,两年平均 ,浙农大 6号和盐引一号分别为蛋白质含量最高和最低的品种 ,泰安和杭州是蛋白质含量最高和最低的试点。年度间和品种与地区及品种与年份之间的互作均达极显著水平。     

十个外引啤酒大麦品种产量及品质分析

为筛选适合甘肃河西地区种植的优质啤酒大麦品种,在甘肃民乐、张掖、山丹、黄羊镇、永昌5个试验点进行两个生长季的品比试验,对10个外引啤酒大麦品种和当地主栽品种的生育期、产量及主要品质性状进行了比较。结果表明,与当地主栽品种甘啤4号相比,10个引进品种生育期相对偏长,有8个品种比对照晚熟;品种Beatrix和Belana表现增产,两年多点试验平均产量分别较对照甘啤4号增产13.31%和8.45%。10个外引啤酒大麦品种的千粒重、发芽势、发芽率达国标一级标准;麦芽品质指标α-氨基氮和糖化力达国标优级标准,浸出物除品种Marnie外均达国标一级标准,库尔巴哈值除品种Xanadu外均达国标一级标准。经产量与品质综合分析,外引啤酒大麦品种Beatrix和Belana在甘肃河西走廊及沿黄灌区气候及土壤条件下表现优良,适宜推广种植。     

Factors predicting malt extract within a single barley cultivar

The amount of extract a malting barley cultivar can produce in the brewhouse will always be of crucial economic importance, and malts with high extract are desired. While the extract level of a particular cultivar is influenced, by genetics, environment and malting practice, it is anticipated that if quality grain is selected and optimally malted, extract levels will not vary much within samples of the same cultivar. Nevertheless, differences are observed in commercial practice, and the objective of this study is to determine which factors are most important in determining extract within a narrow population by use of statistical analysis. Four barley samples of the six-rowed malting cultivar, Tradition, were selected for the current study. All were of acceptable quality for malting. A randomized complete block design using barley sample, kernel size, germination days, and malting type as independent variables was carried out to give a wide variation in extract. Using analysis of variance and stepwise regression, results showed that soluble protein contributed the major variation (79%) in extract under different modification levels. However, under the same modification level, barley protein, 1000-kernel weight, and diastatic power explained the most (74.3%) variation in extract. The predicted extract equation takes the form: Extract=89.3−1.64Pr+0.16KW+0.019DP$\mathrm{Extract}=89.3-1.64\mathrm{Pr}+0.16\mathrm{KW}+0.019\mathrm{DP}$.     

Individual and combined effects of pre- and post-anthesis temperature on protein composition of two malting barley cultivars

The present study has investigated the individual and combined influence of pre- and post-anthesis temperatures and cultivars on the protein composition in barley grains. Two barley cultivars were grown in soil and hydroponic systems in daylight chambers with different pre- and post-anthesis temperatures. Size exclusion (SE)-HPLC was used to evaluate the protein composition in mature barley grains. The results showed that individual and interactive effects of pre- and post-anthesis temperatures and cultivar variations influenced protein composition in the barley grains. Pre-anthesis temperature greatly affected the amounts of total sodium dodecyl sulphate (SDS) extractable proteins (TOTE) and explained 30% of the variation in TOTE. The barley cultivars accounted for 20% of the variation in TOTE. Variation in malting barley cultivars was found to influence the SDS extractable small monomers (41% of the variation). Percentage of SDS un-extractable polymeric proteins in total amount of polymeric proteins (%UPP) was governed by post-anthesis temperature, accounting for 11% of the variation and cultivar differences accounted for 7% of the variation. Thus, the climatic conditions during the specific growing period and a choice of cultivars played a major role in determining the protein composition and ultimately the malting quality of spring barley.     

Amplified Fragment Length Polymorphism (AFLP) Markers for Barley Malt Fingerprinting

Barley is the cerealpar excellencein the production of malt for beer and other alcoholic beverages. In this work, biochemical (hordein A-PAGE) and molecular (RAPDs, AFLPs) markers have been compared for their efficiency in malt fingerprinting. To overcome the difficulties related to the quality of the DNA extracted from grain malt, malted coleoptiles are proposed as useful tissue for the extraction. On the basis of our data, we exclude a fingerprinting system based on A-PAGE hordein analysis because of the degradation of these proteins during the malting process. Comparing molecular markers for their efficiency and repeatability, we indicate AFLP analysis based on template DNA extracted from the tissue of grain malt coleoptile as an excellent tool for malt fingerprinting.     

啤酒大麦品种的千粒重和环境变异研究

千粒重是啤酒大麦重要的产量与品质性状。本研究通过来自全国各地的 10个品种在我国不同地区 8个试验点种植的结果分析 ,表明千粒重在品种间、地区间以及年度间均存在显著差异。两年平均 ,浙农大 6号和单二大麦分别为千粒重最高和最低的品种 ;8个试点中以荆州点的平均粒重最高 ,泰安点最低。     

氮肥运筹对啤酒大麦籽粒品质及产量的影响

为了揭示氮肥运筹对啤酒大麦籽粒品质和产量的调节效应,以啤酒大麦花30为材料,在施纯氮总量225kg.hm-2条件下,研究了不同氮肥运筹对千粒重、β-淀粉酶活性、蛋白质组分含量动态变化和产量及其构成因子的影响。结果表明:(1)随花后天数的增加,大麦籽粒千粒重、β-淀粉酶活性、醇溶蛋白和谷蛋白含量呈现由低到高的变化,而清蛋白和球蛋白含量先急剧上升,后略微下降;(2)增加拔节肥比例能显著增加β-淀粉酶活性、醇溶蛋白和谷蛋白含量,而对清蛋白和球蛋白含量影响较小;(3)千粒重、β-淀粉酶活性及蛋白质组分含量的相关性均达极显著水平;(4)随着氮肥用量后移,有效穗数、产量呈上升趋势,千粒重呈下降趋势。综合考虑各项指标,建议在类似本试验条件下的啤酒大麦生产区,基肥、苗肥、拔节肥比例以6∶3∶1为宜。     

Spectroscopic and chemical fingerprints in malted barley

A unique “Matrix” of malted barley samples was produced to validate spectroscopic procedures for monitoring the malting process. Three critical factors that were examined in controlling the rate of germination were moisture content, temperature and germination time. Of interest to the malting industry, the analysis indicates the potential to identify new germplasm that, under optimized malting conditions, would produce suitably modified malt in three days of germination. It is also clear that the control of both moisture and temperature is essential for undertaking malting studies. The study suggests that Raman and FTIR could usefully complement NIR spectroscopy for monitoring grain during the malting process. For whole grain NIR measurements, the differences between test grain and control grain at optimal wavelengths of 1280 nm and 2224 nm were found to be valuable parameters for tracking progress during the malting process. The study showed the whole grain NIR most likely assessed changing properties of the periphery of the grain. This research suggested that specific calibration models using NIR for predicting malt quality attributes such as diastatic activity on whole malt are misleading and difficult to interpret because they are highly correlated with other carbohydrate/protein-related attributes of the malt.     

Potential longevity (Ki) of malting barley (Hordeum vulgare L.) grain lots relates to their degree of pre-germination assessed through different industrial quality parameters

Barley (Hordeum vulgare L.) grain germination is required to perform the malting process. Maintenance of barley seed viability during storage is crucial for the malt industry; and modern cultivars are bred for rapid grain dormancy release after physiological maturity. Low dormancy level combined with rain close to harvest induces pre-germination/pre-harvest sprouting damage. Pre-germination might not affect viability in the short term after harvest, but it could reduce potential longevity (K_i) of a barley seed lot. K_i value is inherent for each barley lot; however, its determination is time-consuming which precludes its assessment at an industrial scale. In this study we sought quantitative relationships between K_i and the pre-germination degree of barley grain lots, assessed through quality tests routinely performed by malthouses [Falling Number (FN), α-Amylase Activity and Carlsberg]. Field pre-germinated lots from one old barley cultivar (Quilmes Palomar) and artificially pre-germinated lots from major varieties currently grown in Argentina were used. Associations between K_i and values obtained from all quality tests analysed were found for Q. Palomar. However, FN was the parameter that yielded the best and simplest explanation of K_i variability. A significant positive linear K_i -FN relationship was also obtained for each modern barley cultivar.     

Predicting pre-harvest sprouting susceptibility in barley: Looking for “sensitivity windows” to temperature throughout grain filling in various commercial cultivars

Pre-harvest sprouting (PHS) is common in cereals that lack grain dormancy if maturing grain is exposed to rain. This phenomenon leads to immediate loss of seed viability, and since the malting process requires germination, its occurrence is highly undesirable in malting barley crops. Dormancy release rate is genetically and environmentally controlled. We evaluated the effect of temperature during grain filling on the dormancy release pattern (and then on the PHS susceptibility) of grains from five malting barley (Hordeum vulgare L.) cultivars widely sown in Argentina, with the aim of predicting PHS susceptibility of a barley crop from easy-to-gather data. Barley cultivars (Quilmes Ayelén, Q. Palomar, Q. Painé, B1215 and Scarlett) were sown on different dates over a 3-year period for generating variability in the thermal environment during grain filling. The period from pollination to physiological maturity (PM) was adjusted to a thermal time (TT) scale, which was then arbitrarily divided into 50 °C d intervals. Mean air temperature within each interval and for the whole filling period was calculated for the different sowing dates. Dormancy release pattern was followed by determining a weighed germination index (GI) throughout grain filling and maturation. We sought a linear relationship between temperature during grain filling and GI at some moment after PM. For all barley cultivars, except B1215, a significant (p < 0.001) and positive correlation was found between the GI of grains with 10–20% moisture content (fresh basis) and mean temperature within TT intervals located at the last stages of seed development. Then, simply temperature-based models for predicting crop PHS susceptibility were generated for each barley cultivar. Moreover, we intended a single, universal prediction model constructed with data from all cultivars. Two general forms were proposed, but the relationships were slightly less tight when each barley cultivar model was used. A preliminary validation for each cultivar model was done for three genotypes with independent data from four sites of the major barley production area in Argentina. When comparing experimental and field data regressions we did not find significant differences in slope for any cultivar (p > 0.25). However, most of the observed GIs were higher than predicted. This upwards displacement of GI–temperature relationship suggests the role of other environmental factors (i.e. water and soil N availability, day length), differing among tested locations. We are currently evaluating and quantifying the effect of these factors with the aim of improving PHS susceptibility prediction in malting barley crops.     

Combining ability of barley flour pasting properties

Malt extract is one of the major traits contributing to high malting quality and thus a major objective in malting barley breeding programs. Understanding the genetic behaviour of this trait could make selection more efficient. However, the measurement of this trait is very time-consuming and cannot be done in a single plant since it needs a certain amount of grain. In this paper, 10 different varieties with different malting quality were selected to make two 6 × 6 half-diallel crosses for the purpose of studying the genetic behaviour of flour pasting properties, in particular pasting temperature which has been shown to be closely related with malt extract. The pasting properties were measured with a Rapid ViscoAnalyser. Both Australian malting varieties showed significantly higher general combining ability for lower pasting temperature (higher malt extract). The Japanese malting variety also appeared to be a good parent for lower pasting temperature. All the other feed varieties which are used in the breeding programs for improving waterlogging tolerance or salinity tolerance showed significantly higher pasting temperature. Since specific combining ability was not significant, the selection of parents when breeding for pasting temperature can be based on the pasting temperature of the parents. Combined with the fact that only a small amount of grain is needed for the measurement of pasting temperature, the selection can be made in early segregating generations. Preliminary study showed that a major QTL associated with pasting temperature was located on chromosome 7H, indicating the possibility of marker assisted selection for this trait.