不同小麦品种蛋白质含量与面团稳定时间的相关回归分析

试验选取河南地区8个主栽小麦品种,采用近红外光谱技术对其蛋白质含量和面团稳定时间进行测定,并对试验材料进行相关回归分析。试验结果表明,大部分小麦品种的蛋白质含量介于13.55%～15.09%之间,蛋白质含量最高的是‘淮麦29’,最低的是‘鲁农116’。面团稳定时间4.6～8.9 min在之间,有7个品种的面团稳定时间是<7.0 min。结合相关国家标准,8个小麦样品有4个品种为中强筋小麦品种;3个为强筋小麦。将试验测得的蛋白质含量与面团稳定时间两项指标进行相关回归分析,结果显示两者之间存在着显著正相关关系。试验结果期望为小麦品种培育、栽培及后续加工预测提供参考依据。     

不同灌溉处理对小麦蛋白组分和面团流变学特性的影响

为阐明不同灌溉处理对强筋和弱筋小麦品质的影响,以藁城8901（强筋）和山农1391（弱筋）品种为材料,设3个灌溉处理,于花后7~35 d分别测定其籽粒蛋白质及其组分含量、以及粉质仪和拉伸仪参数。结果表明,对于籽粒清蛋白和球蛋白,随灌溉量的增加,藁城8901和山农1391的含量均提高;适量灌溉（浇起身水和孕穗水各75 mm）能提高强筋品种籽粒醇溶蛋白和谷蛋白含量,降低弱筋品种的含量。藁城8901籽粒谷蛋白、GMP含量、HMW-GS含量、面粉沉淀值、粉质仪参数和拉伸仪参数显著高于山农1391。灌溉能显著提高藁城8901面粉沉淀值、粉质仪参数和拉伸仪参数,山农1391面团流变学特性对灌溉的反应较迟钝,这与不同灌溉处理对不同品种籽粒醇溶蛋白、谷蛋白、GMP和HMW-GS含量的影响密切相关。     

淀粉和面筋蛋白对面团流变特性的影响

不同的面制食品对原料面粉的加工性能有不同的要求。面团的加工性能包括弹性、塑性、流动性、黏性和延伸性等。面团主要成分是淀粉和面筋蛋白，内部呈蜂窝状结构，是一种典型的生物高分子黏弹性材料。它既有黏性流体的某些性质，也具有弹性固体的某些特征。面团的流变学特性直接影响产品的加工品质。另外，研究面团的流变学特性对理解面团的化学性质及结构也非常重要。所以，有必要对影响面团流变特性，尤其是黏弹性的各种因素进行探讨。[编者按]     

不同套种模式对小麦产量的影响

通过对不同套种模式小麦群体发育情况的调查分析,在6：2式套种（6行小麦占地1．25m,2行棉花占地0．6m）模式下,小麦理论减产率为32．43％,绝对边行优势为18．62％,套种实际减产率为14．71％,相对边行优势为26．98％;12：2：2式套种（12行小麦占地2．6m,2行棉花和2行西瓜占地1．2m）模式下,小麦理论减产率为33．33％,绝对边行优势为18．62％,套种实际减产率为14．71％,相对边行优势为38．38％。     

不同淀粉对面团流变学特性的影响

通过向面粉中添加不同性质的淀粉,运用粉质仪进行面团粉质试验,研究不同淀粉对面团流变学特性的影响。结果表明,随着玉米淀粉、木薯淀粉、红薯淀粉添加量的增加,面团的吸水率、形成时间、稳定时间、弱化度等都有着显著的变化,均可改善面团的流变学特性、面团的韧性、延伸性和筋力。与对照相比,玉米淀粉能有效改善面团的硬度和弹性,添加量应在8%以下;木薯淀粉对面团的影响不明显,添加量应在2%以下;红薯淀粉由于颗粒比较大,面团的吸水率随之变化较明显,最适添加量不得超过10%。     

小麦基础日粮添加不同水平木聚糖酶对猪生产性能的影响

结果表明，小麦日粮猪的日增重与日粮中添加木聚糖酶呈显著正相关；料重比显著降低，提示对小麦日粮来讲，木聚糖酶在提高猪生产性能方面具有重要作用。经济效益分析表明，当小麦价格低于玉米时，简单地用小麦大量代替玉米，添加木聚糖酶，在养猪生产上是可行的，适当增加酶的添加量，可提高生产性能和经济效益。     

不同乳化剂对冷冻面团酵母活性的影响

研究了面包生产中常用的5种乳化剂硬脂酰乳酸钠(SSL)、蔗糖酯(SE)、单甘酯、二乙酰酒石酸单甘酯(DATEM)以及卵磷脂对冷冻前后面团发酵性能的影响。结果表明,添加乳化剂会影响面团的胀发力,其中添加0.5%SE、0.5%单甘酯和0.5%DATEM对冷冻前新鲜面团的胀发力有改善效果,并可显著降低冷冻对面团胀发力的负面影响,SSL和卵磷脂对新鲜面团的胀发力影响不显著,卵磷脂会显著降低冷冻面团的胀发力;5种乳化剂均可提高面团冷冻后酵母菌的存活率,其中以0.5%单甘酯和0.5%DATEM的效果为好,与未添加任何乳化剂的面团相比,达显著差异水平。总体上,SE、单甘酯和DATEM这三种乳化剂在保持冷冻面团酵母菌的活性及胀发力方面更具有优势。     

蛋白质和淀粉含量对小麦面团流变学特性的影响

以小麦强筋品种山农12和中筋品种山农11为材料,利用面团重组方法,在保持面粉中其他成分不变的情况下,配成不同蛋白质和淀粉含量的样品,研究了蛋白质和淀粉含量对面团流变学特性的影响。结果表明,当蛋白质含量依次为120%、140%和160%时,两品种面团的峰值高度和峰值宽度呈显著增加趋势(P<0.05),最大抗延伸阻力山农12分别为40.7 CK）、49.8 g、59.0 g和71.6 g,山农11分别为20.6（CK）、29.5 g、32.1 g和36.0 g,呈增加趋势,而延伸性变化不大;当淀粉含量依次为85%、90%和95%时,两品种面团的峰值高度和峰值能量呈显著降低趋势(P<0.05),延伸性山农12 分别为110.8 mm（CK）、68.8 mm、59.2 mm和36.5 mm,山农11分别为81.6 mm（CK）、75.8 mm、59.1 mm和50.3 mm,呈降低趋势,而最大抗延伸阻力变化不大。     

普通小麦面筋蛋白和面团流变学性质间的相关性

本文报道了28个普通小麦栽培品种的面团流变学性质与胚乳蛋白类型和数量间的相关性。采用不同方法来分析了这些品种的等位基因组成以及影响面筋结构的各种蛋白质的相对数量。无论是面团强度（W）还是抗拉强度／伸长性（P／L）都与等位基因组成无关。具有相同等位基因组成（即对麦谷蛋白而言）的不同小麦表现出不同的面团流变学性质。麦谷蛋白尤其是高分子量（HMW）麦谷蛋白亚基和x型麦谷蛋白对W和P／L性状是最具影响力的成分。这些蛋白质好象能增强面团强度，并且是面筋网纹的主要组分。     

不同收获期对小麦种子活力及物理性状的影响

为研究黄淮麦区小麦种子成熟过程中种子活力与物理性状变化之间的关系,确定适宜的收获期,以西农20和周麦18为试验材料,研究收获期对种子活力和物理性状的影响.结果表明,不同品种、不同收获期对种子的活力指标的影响达到极显著水平;西农20活力指标均在花后34 d趋于稳定,周麦18的物理指标和活力指标在花后40 d达到峰值;典型...     

Effects of the 6VS.6AL translocation on agronomic traits and dough properties of wheat

Nineteen common wheat cultivars and advanced lines carrying a 6VS.6AL translocation and five parents were sown at two locations in Jiangsu in 2004–05 season to assess the effects of the translocation on grain yield and dough properties. In general, there were no significant differences between 6VS.6AL lines and their recurrent parents in agronomic, mixograph and starch pasting traits, including grain yield, grains/spike, grain weight/spike, mixing time and peak viscosity. 6VS.6AL lines showed slightly but significantly higher thousand-kernel weight and plant height, and small negative effects on test weight, flour yield and flour colour. However, significant variation occurred for all traits among sister lines from the same cross, indicating that additional selection could lead to further improvement. It was concluded that the 6VS.6AL translocation can be used in wheat breeding programs as a donor of resistance to powdery mildew with no obvious undesirable effects on agronomic and quality traits.     

Relationship between common wheat (Triticum aestivum L.) gluten proteins and dough rheological properties

This paper reports the correlation between the rheological properties of bread wheat dough and the types and quantities of endosperm proteins in 28 common wheat cultivars. Different methods were used to analyse the allelic composition of these cultivars and the relative quantities of the different proteins contributing to the gluten structure. Neither dough strength (W) nor tenacity/extensibility (P/L) correlated with allelic composition. Different wheats with the same allelic composition (i.e., with respect to glutenins) showed different rheological properties. The glutenins were the most influential components of W and P/L, especially the high molecular weight (HMW) glutenin subunits and in particular the type x form. These proteins seem to increase W and are the main constituents of the gluten network. The gliadins and low molecular weight (LMW) glutenin subunits appear to act as a “solvent”, and thus modify the rheological properties of the dough by either interfering with the polymerisation of the HMW glutenin subunits, or by altering the relative amounts of the different types of glutenin available. Thus, the protein subunits coded for by the alleles Glu-B1x7 and Glu-D1x5 stabilised the gluten network, whereas those coded for by Glu-B1x17 and Glu-D1x2 had the opposite effect. Dough properties therefore appear to depend on the glutenin/gliadins balance, and on the ratio of the type x and type y HMW proteins. The influence of external factors seems to depend on the allelic composition of each cultivar.     

Glutenin allelic variation and 1AL.1RS effects on dough mixing properties of wheat grown in irrigated and rainfed environments

Wheat (Triticum aestivum L.) glutenin allelic variation and presence of the 1AL.1RS wheat-rye (Secale cereale L.) translocation play important roles in determining end-use quality. This study was conducted to evaluate the effects of high and low molecular weight glutenin alleles and 1AL.1RS on dough mixing properties of 189 recombinant inbred lines (RILs) from the cross TAM 107-R7/‘Arlin’ grown in irrigated and rainfed Colorado (USA) environments. The results indicated that (1) higher values (P < 0.05) of some dough mixing properties were observed for Glu-A1b versus Glu-A1a, Glu-B1b versus Glu-B1c, Glu-D1d versus Glu-D1a, and non-1AL.1RS versus 1AL.1RS; (2) no differences in Mixograph properties were found for Glu-A3c versus Glu-A3e, Glu-B3e versus Glu-B3g, or Glu-D3a versus Glu-D3b; (3) although variation at some glutenin loci had little effect on Mixograph properties, pairwise combinations of glutenin loci or a glutenin locus combined with 1AL.1RS affected most Mixograph traits; and (4) in general, the effects of glutenin alleles and 1AL.1RS on dough mixing properties did not differ greatly between the irrigated and the rainfed environment. These results will be useful for assessing potential wheat quality and directing wheat breeding efforts in Colorado and similar environments.     

Effect of cooling rate on high temperature mechanical properties of weathering steel

High temperature mechanical properties are key factors which affect fracture production during deforming process of continuous casting. High temperature properties of weathering steel Q450NQR1 are tested in 3 cooling rates (1.65, 5, 10 ℃/s) using Gleeble thermo-mechanical simulator. Specimens appear austenite dynamic recrystallization at 1 050 ℃, and the ductility reaches the lowest point and the reduction of area approaches 23% at 850 ℃ in 3 cooling rates. As the cooling rate increases, the low ductility area where cracks are easy to be produced in slabs is enlarged and extended towards low temperature, and the ductility troughs are deepened. The increase of the cooling rate decreases the tensile stress and yield stress, while when the cooling rate increases to some degree, it doesn’t affect the stress. The low cooling rate decreases the film or network ferrite producing in austenite grain boundary, and the carbonitride of microalloy is enwrapped in matrix, which is helpful to improve the ductility of steel.     

Effect of high proton beam irradiation on pasting properties of rice starch

Rice seed was treated by high proton beam irradiation up to 1,200 Gy in order to elucidate physicochemical properties of irradiated rice starch. The decrease of amylose content in two rice cultivars ranged 3.5 to 3.6% compared to the non-irradiated rice under the highest proton beam irradiation (1,200 Gy). Gel consistency in japonica rice cultivar Ilpum was significantly increased with increasing proton beam irradiation. Its values approached 9.7 in the Ilpum rice cultivar and 8.7 cm in the Hanmaum rice cultivar. The peak viscosity, hot peak viscosity, cool peak viscosity, and setback were significantly decreased with increasing proton beam dose. High proton beam irradiation caused a significant decrease in the onset temperature (T _o ), peak temperature (T _p ), conclusion temperature (T _c ), and enthalpy change (ΔH). Gelatinization range (R) in two rice cultivars was more broaden in higher proton beam irradiation than in low proton beam irradiation. The crystallinity degree of two rice starches irradiated with high proton beam was significantly increased and it ranged from 3.25 and 4.39% compared to the non-irradiated rice starches. It might be deduced that proton beam irradiation causes changes of starch, especially at high irradiation of proton beam.     

Effect of nitrogen on microstructure and properties of SWRH82B wire rod

The microstructure, mechanical properties, tensile fractures and the precipitation of the second phase of vanadium microalloyed wire rods with different nitrogen contents are studied by hydraulic universal testing machine, scanning electron microscopy(SEM) and transmission electron microscopy(TEM) . The results show that the interlamellar spacing of pearlite is smaller in high nitrogen steel; the high nitrogen steel has higher yield strength, tensile strength and lower elongation and reduction of area; there are more inclusions on the tensile fracture surfaces of the high nitrogen steel; and in high nitrogen steel, the size of precipitation, mainly precipitating at dislocation or the boundary of austenite, is finer than that of low nitrogen steel, what is more, fine V(C,N) particles are concluded in the precipitations.     

不同施氮量对秋播超甜玉米产量性状的影响

摘要：田间试验、常规考种分析6种不同施氮水平对秋播“华珍”超甜玉米产量性状的影响,为超甜玉米种植过程中合理施用氮肥提供科学的指导依据。结果表明：6组不同施氮量对超甜玉米叶面积、穗长、穗粗、穗行粒数、百粒鲜重和百粒干重都有显著的增产效果。其中有效增加促进叶片面积,穗长、穗粗、穗行粒数以及鲜苞产量的最佳氮肥施用量在225kg/hm2~300kg/hm2之间。不同氮肥水平对百粒鲜重和百粒干重也有显著增产效果,最佳施氮量在300kg/hm2~375kg/hm2之间,因此通过调控氮肥的施用量来增加超甜玉米产量是可行的,其中约300kg/hm2的氮肥施用量既能有效提高超甜玉米主要产量性状,降低生产成本,也能避免氮肥施用过多对玉米植株生长以及生态环境造成不良影响。     

Effect of turgor on micromechanical and structural properties of apple tissue: A quantitative analysis

The effect of turgor on the micromechanical properties of apples (Malus domestica Borkh. cv Jonagored) and its relation to structural parameters of the cells was investigated. Mechanical measurements were carried out using a miniature tensile stage mounted under a microscope. Turgor was manipulated by soaking tissue samples in iso-, hypo- or hypertonic mannitol solutions. Samples were then subjected to tensile and compression tests, during which the deformation of the individual cells was recorded. In both tests, sigmoidal stress–strain curves were found, where stiffness increases with strain. With increasing turgor, strain at maximum stress became significantly (p < 0.05) lower while stiffness increased, but no clear effect on failure stress was found. As expected, fresh apples proved to be firmer and stiffer than stored apples, while the influence of turgor was the same. Measurement of initial cell parameters (area, length, width, aspect, roundness) showed that the apples in the experiment were homogeneous, having comparable cell sizes. Manipulation of turgor did not affect initial cell parameters, but the magnitude of cell deformations was clearly influenced. Larger deformations were found in flaccid cells. Changes in length and width were closely related to strain measurements. In conformity with micromechanical parameters, deformations were smaller in stored than in fresh apples.     

秸秆覆盖对土壤理化性状、微生物及生态环境的影响

研究表明,相对秸秆焚烧,秸秆还田不但可以减少大气污染,更重要的是秸秆还田可以有效调节土壤水、肥、气、热,提高土壤孔隙度、提高水分渗透率、增加土壤水稳性团聚体含量、提高土壤有机质、提高土壤有效养分（N、P、K等）、提高土壤微生物生物量、增强各种土壤酶的活性,同时还可以有效降低各种重金属对土壤的污染;从经济效益来讲,还可以提高作物的产量。总之,秸秆还田可以使生态、社会和经济效益显著提高,是农业持续发展的有效措施和途径之一。     

生物黑炭对设施土壤理化性质及蔬菜产量的影响

选取典型日光温室,通过一年两季田间小区试验,研究生物黑炭不同用量对设施土壤理化性质及蔬菜产量的影响,以期为生物黑炭在设施土壤中合理运用提供参考。结果表明,设施土壤施用生物黑炭与习惯处理相比,能显著降低土壤容重2.65%~15.73%,提高土壤CEC 1.03%~5.46%,提高土壤有机碳含量7.28%~24.95%,增加土壤速效钾含量19.06%~168.5%,施用量越大效果越明显;施用生物黑炭也增加了土壤水解氮和速效磷含量,但与习惯处理相比差异不显著。生物黑炭本身pH较高,但经过蔬菜整个生长季后,对土壤pH影响不大;生物黑炭矿物质含量较高,增加土壤养分的同时也提高了土壤全盐含量。低量生物黑炭对蔬菜产量影响不大或有提高作用,但高量生物黑炭会造成蔬菜减产,因此,设施土壤生物黑炭施用量不宜过高。