An investigation on the effect of heat-moisture treatment on baking quality of wheat by using response surface methodology

Effect of heat-moisture treatment on quality properties of two bread wheats (cvs. Tosunbey and Bayraktar) were investigated by using response surface methodology (RSM). Temperature and moisture conditions in the experimental design were in the range of 55–95 °C and 13–19%. Heat-moisture treated grains were milled into flour and quality properties were determined. The optimum moisture-temperature combination for the highest dry gluten, Zeleny sedimentation, Alveograph W and bread volume values were estimated as 14%-63 °C for Tosunbey and 19%-55 °C for Bayraktar samples. Alveograph W seems to be a good indicator of baking quality for wheats treated at higher temperatures. In order to describe the relationship between the dependent and independent variables (moisture, temperature), the response values were fitted by second order polynomial models. Significance analysis showed that the effect of both moisture and temperature on dry gluten content, sedimentation and falling number values for Tosunbey; falling number and damaged starch values for Bayraktar were significant (p < 0.05). The effect of temperature on Farinograph water absorption, W and P/G, bread volume and firmness values were significant for both cultivars (p < 0.05). It can be concluded that improvement in baking quality can be achieved and flours with different properties can be produced by heat-moisture treatments on wheat.     

Identification of CIMMYT spring bread wheat germplasm maintaining superior grain yield and quality under heat-stress

Unpredictable temperatures and rainfall associated with climate change are expected to affect wheat (Triticum aestivum L.) production in various countries. The development of climate-resilient spring wheat cultivars able to maintain grain yield and quality is essential to food security and economic returns. We tested 54 CIMMYT spring bread wheat genotypes, developed and/or released over a span of 50 years, in the field for two years under optimum sowing dates, as well as using two delayed sowing dates to expose crops to medium and severe heat-stress conditions. The grain yield and yield components were severely affected as the heat-stress increased. Two contrasting groups of 10 lines each were identified to determine the effect of heat-stress on bread-making quality. The first set included entries that produced high yields in optimal conditions and maintained higher yields under heat-stress (superior-yielding lines), while the second set included genotypes that did not perform well in the environment with high temperature (inferior-yielding lines). We identified genotypes exhibiting bread-making quality stability, as well as the quality traits that had higher correlation with the loaf volume in the environment without stress and under heat-stress. Of all the quality traits tested, dough extensibility (AlvL) and grain protein content had a significant influence in heat-stress adaptation. Most of the lines from the superior-yielding group were also able to maintain and even improve quality characteristics under heat-stress and therefore, could be used as parents in breeding to develop high-yielding and stable quality wheat varieties.     

水肥因子对小麦籽粒及面包烘烤品质的影响

 就水肥因子对小麦籽粒品质及面包烘烤品质的影响进行了初步研究。结果表明：籽粒蛋白质含量，干、湿面筋含量，沉降值等籽粒品质性状及多数面包烘烤品质性状均受水肥措施的显著影响。增加灌水会降低小麦籽粒品质，对烘烤品质有一定的稀释效应，但这种稀释效应可通过增加施肥得以缓冲。在面包烘烤品质性状中，面包体积和比容是两个重要的品质指标，一定的水肥措施可使之得以改善。     

面包小麦育种早代品质鉴定方法

介绍了面包小麦对品质的要求和育种早代品质鉴定方法。     

面包用小麦的改良与选育途径

通过对小麦不同亲本材料的单交、正反交、复合杂交的后代主要品质性状分析 ,探讨选育优质面包小麦的有效方法。杂交早代进行沉降值测试和SDS -PAGE电泳谱带分析 ,可快速测定早代的主要品质性状和优质基因。     

我国春麦区部分小麦品种品质状况分析

1999年将 38份春小麦品种 (品系 )种植于内蒙古呼和浩特 ,对其磨粉品质和面包烘烤品质进行了评价。结果表明 ,我国春小麦品种的面包烘烤品质较差 ,不同地区品种间品质差异较大 ,辽宁和内蒙品种的磨粉品质和面包烘烤品质优于其它地区的品种。回归分析表明 ,蛋白质含量和单位蛋白质含量的面包体积决定了面包体积总变异的 99.9% ,硬度、沉淀值和吸水率对面包总分有重要作用。品种的出粉率主要取决于 1心槽路出粉率 ,2心和 1皮槽路出粉率对出粉率贡献也较大。高分子量麦谷蛋白亚基 (HMW GS)Glu A1和Glu D1位点的等位变异与品质性状密切相关。面包烘烤品质的改良应在分析HMW GS的基础上 ,将硬度作为选择指标之一 ,适当提高蛋白质含量 ,重点加强对沉淀值的选择     

Wheat grain quality under increasing atmospheric CO2 concentrations in a semi-arid cropping system

We investigated wheat (Triticum aestivum) grain quality under Free Air CO₂ Enrichment (FACE) of 550 ± 10% CO₂ μmol mol⁻¹. In each of two full growing seasons (2008 and 2009), two times of sowing were compared, with late sowing designed to mimic high temperature during grain filling. Grain samples were subjected to a range of physical, nutritional and rheological quality assessments. Elevated CO₂ increased thousand grain weight (8%) and grain diameter (5%). Flour protein concentration was reduced by 11% at e[CO₂], with the highest reduction being observed at the late time of sowing in 2009, (15%). Most of the grain mineral concentrations decreased under e[CO₂] - Ca (11%), Mg (7%), P (11%) and S (7%), Fe (10%), Zn (17%), Na (19%), while total uptake of these nutrients per unit ground area increased. Rheological properties of the flour were altered by e[CO₂] and bread volume reduced by 7%. Phytate concentration in grains tended to decrease (17%) at e[CO₂] while grain fructan concentration remained unchanged. The data suggest that rising atmospheric [CO₂] will reduce the nutritional and rheological quality of wheat grain, but at high temperature, e[CO₂] effects may be moderated. Reduced phytate concentrations at e[CO₂] may improve bioavailability of Fe and Zn in wheat grain.     

新疆面包小麦品质性状环境变异及配粉效果的研究

为了进一步了解面包小麦品种在不同生态区的品质变异状况，通过实验室方法对新疆引进和选育的优质面包小麦新春9号和Y20在新疆乌鲁木齐市、石河子市和奇台县三个不同生态环境下的品质性状表现进行了检测分析。结果表明，小麦的加工品质易受环境影响，同一品种在不同地区种植其加工品质性状存在一定差异，但不同品种对环境反应的敏感性不同，新春9号在不同地区的品质性状差异小于Y20。虽然两个品种的综合品质性状都达到了国家一、二级面包小麦标准，但两个品种的加工品质性状差异还是较大的，其中，石河子产Y20的品质性状表现最为理想。因此，在进行品质性状环境变异研究的同时，对两个品种不同比例的搭配进行了粉质、拉伸、吹泡参数及烘焙品质的测定，结果表明将不同点的新春9号与石河子产Y20搭配，随着Y20比例的增加，其搭配后的品质在不断优化；对奇台产Y20与乌鲁木齐产新春9号以不同比例配粉，其中40%奇台产Y20与60%乌鲁木齐产新春9号配粉的效果最好；考虑到生产成本，则后者配粉效果更理想。     

小麦EST—SSRs分子标记的特性及其遗传作图

为了解普通小麦EST来源的微卫星的多样性,从大约1000个包含微卫星的ESTs中设计了300对引物,研究和评估了它们的多态性水平,并且将多态性标记加入到现有的遗传图谱中。在五种不同类型的重复单元中,三个碱基的重复单元出现最多,占到77％。几乎所有的EST—SSRs标记（99．3％）的重复单元都含有G-C碱基对。37．4％的微卫星都是四次重复。对于扩增和多态性,300对引物中有60对没有扩增,21．3％的扩增引物没能产生预期的扩增片断。58％的标记至少在所用8个材料的一个中显示出多态性。W7984和Opata组合表现出最高的多态性水平。大多数普通小麦EST—SSRs标记的重复次数小于10,并且4次重复是最为普遍的。81个新的EST—SSR位点被添加到两个已有的参照遗传图谱中（62个加到ITMI,19个加到CTCS）。研究结果表明小麦EST-SSRs标记展示了一些不同于基因组微卫星的特异特征,在标记发展和其他遗传应用中,这就使得它们能够成为一种非常有价值的资源。     

优质强筋小麦与运黑101复配粉的面包品质研究

为更广泛利用黑小麦,用优质强筋小麦运旱115、运旱618的面粉分别与中筋黑小麦运黑101的面粉进行搭配,研究了不同复配粉的面筋指数变化规律和面包加工特性。结果表明,两个优质强筋小麦粉与中筋黑小麦运黑101复配,可以显著改善中筋黑小麦运黑101的面筋指数、抗延阻力、稳定时间;优质强筋小麦粉与运黑101面粉占比相等时,运旱115、运旱618对运黑101的面筋指数改进率较大,分别为10.57%、10.51%。综合分析对面包品质影响较大的硬度、胶黏性、咀嚼性等质构指标,发现运旱115与运黑101配粉比例为8∶2、5∶5时,运旱618与运黑101配粉比例为7∶3、6∶4时,运黑101面粉品质改善显著,用其制作的面包体积大、品质好。