麦谷蛋白与面条品质关系的研究

研究了酸可溶麦谷蛋白、酸不溶性麦谷蛋白、高相对分子质量麦谷蛋白亚基、低相对分子质量麦谷蛋白亚基对面条质构品质的影响.结果表明:酸不溶性麦谷蛋白能增强熟面条的硬度、粘结性、粘合性、咀嚼性、最大剪切应力和拉断力;低相对分子质量麦谷蛋白亚基能增强熟面条的硬度、粘合性、咀嚼性、回复性、拉断力和拉伸应变.     

冻藏时间对麦谷蛋白和麦醇溶蛋白二级结构及面团性能的影响研究

分别对小麦醇溶蛋白和麦谷蛋白在-18℃下冻藏0²8d后其巯基和二硫键含量以及二级结构的变化情况进行研究,并分析了变化可能的内在机理;进一步探讨了冻藏导致的面团质构变化与两种面筋蛋白结构变化的对应关系。结果表明:冻藏处理使麦醇溶蛋白和麦谷蛋白中巯基含量增加、二硫键含量减少,α-螺旋和β-转角结构含量下降,β-折叠结构含量升高;其中,冻藏处理对麦谷蛋白二级结构的影响程度要明显大于麦醇溶蛋白。质构研究结果表明:两种蛋白质中二硫键、α-螺旋和β-转角结构含量的减少,对冻藏后面团粘性、弹性、硬度的降低有着重要影响。      

小麦粉面包烘烤品质指标的研究 Ⅰ.逐步回归分析筛选关键性指标

本实验应用逐步回归方法研究了河南50个小麦品种(系)的面包烘烤品质各指标间的关系,结果表明:面包评分、体积和比容均是评价面包品质优劣的综合性指标。和体积,比容相比较,以面包评分和烘烤品质各指标建立的回归方程具有更高的F值,复相关系数也较高。用面包评分代表面包烘烤品质可能较体积和比容更可靠更稳定。面包评分可看作是评价值和粉力二者综合作用的结果。     

不同面筋蛋白组分对小麦淀粉消化特性的影响机理

分别将面筋蛋白、谷蛋白及醇溶蛋白与淀粉按一定质量比（14∶86）混合,运用流变仪、热重分析仪及激光共聚焦显微镜等手段分析不同面筋蛋白组分与淀粉/α-淀粉酶之间的相互作用,以明确面筋蛋白及其不同组分对淀粉消化特性的影响及潜在机理。结果表明：与纯小麦淀粉相比,添加面筋蛋白、谷蛋白及醇溶蛋白使酶解120 min的淀粉消化率分别下降了39.93%、49.48%及26.61%。淀粉与不同面筋蛋白组分之间通过氢键相互作用形成了更稳定的复合物,提高了样品的热稳定性。与面筋蛋白和醇溶蛋白相比,添加谷蛋白在淀粉基质周围形成了更加致密的物理性屏障,更大程度地抑制了酶对淀粉的水解。此外,谷蛋白对α-淀粉酶的抑制率最高（约79%）,激光共聚焦观察到的结果也证实了谷蛋白和α-淀粉酶之间的结合程度更高。研究结果有助于丰富典型蛋白质组分调控食品体系中淀粉消化的机理,为低血糖指数食品的开发提供一定理论指导。     

High‐molecular‐weight glutenin subunit composition of Pakistani hard white spring wheats grown at three locations for 2 years and its relationship with end‐use quality characteristics

Eleven Pakistani hard white spring wheat cultivars, along with one durum wheat and two hard white American‐grown wheat cultivars, were evaluated for their high‐molecular‐weight (HMW) glutenin subunit composition via sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE). The relationships among different quality characteristics and between these characteristics and HMW glutenin subunits were computed. Three to six HMW glutenin subunits were observed in Pakistani bread wheat cultivars. The presence of HMW glutenin subunits was not affected by growth locations or crop years. However, variations in intensities were observed. Correlations were noticed between certain HMW glutenin subunits and some quality attributes, such as protein, farinograph dough development time, farinograph water absorption, loaf volume and mixograph peak height. The presence of HMW glutenin subunit 20 in the older wheat cultivars C591 and C273, known for excellent chapati quality, indicated a possible relationship between this band and chapati quality. This observation will need to be confirmed by testing a larger number of wheat samples known to have characteristics for both good and poor chapati quality. © 2000 Society of Chemical Industry     

Polymerization and Mechanical Degradation Kinetics of Gluten and Glutenin at Extruder Melt-Section Temperatures and Shear Rates

Thermal polymerization and mechanical degradation rates were measured for wheat gluten and glutenin at 25–30% moisture. Changes in soluble protein and disulfide bonds were measured at 85°C to 180°C, residence times of 2–60 set and shear rates of 10–275 sec^-l. Polyrnerization rates without shear were evaluated using isothermal analysis. An extrusion rheometer was used to simulate extruder conditions to determine the combined polymerization-degradation rates. Molecular weight distributions of soluble reaction products were determined using liquid size exclusion chromatography. Activation energies were 0.60–2.1 kcal/ mol, 2.0–8.2 kcal/mol, and 0.50–0.90 kcaVmo1 and reaction orders were 0.5–2.0, 0.8–1.5, and 0.6–0.7, respectively for polymerization without shear, polymerization with shear, and degradation.     

谷蛋白大聚体在小麦加工中的作用

谷蛋白大聚体(GMP)是小麦籽粒中最重要的蛋白质聚合体,不溶于1.5%SDS溶液,且分子质量较大,以颗粒形式存在,粒径范围为1~300μm;其含量和分子结构与食品加工品质密切相关,在面制食品加工中的作用远大于可溶性谷蛋白聚合体和单体蛋白。谷蛋白大聚体含量高的小麦品种,其面筋、面团的强度和弹性较大,面包烘烤品质较好,面条拉伸特性较好。谷蛋白大聚体在面团和面过程中会发生解聚,其含量、粒径和分子质量均降低;而在面团醒发过程中又会发生重聚。面条面坯形成过程中,谷蛋白大聚体含量的降低程度远低于传统面团,而凝胶强度的变化趋势则与传统面团相反。     

应用灰色关联分析对麦谷蛋白各组分含量与小麦面包烘烤品质指标间关系的探讨

本文应用灰系统理论中的关联分析方法,初步探讨了麦谷蛋白各组分含量与面包烘烤品质指标间的关系。文中将面包烘烤品质中的面包评分,面包体积,评价值三项指标作为母因素,讨论了与其它11项指标的联系密切程度,不仅验证了剩余蛋白含量可以作为评价小麦面包烘烤品质的重要指标,同时得出了评价面包烘烤品质的其它几个指标的重要程度。     

方便面制作过程中麦谷蛋白提取率变化的研究

研究了方便面制作过程中 ,麦谷蛋白提取率在面粉、熟化后面团、湿面条、蒸制后面条及油炸后面条 5个状态点上的变化情况 .结果表明 ,在方便面制作的整个过程中 ,麦谷蛋白含量呈不断下降趋势 .小麦品种不同 ,麦谷蛋白在各阶段的下降程度也不相同 .总体来看 ,其衰减程度在由湿面条至蒸熟后面条的过程中最大 ,在由蒸制后面条到油炸后面条的过程中最小 .麦谷蛋白提取率的降低主要来源于 2个因素 ,一是其肽链上二硫键数目的增加 ,二是蛋白质的热变性作用     

The relationship between HMW glutenin subunit composition and the bread-making quality of British-grown wheat varieties

Based on previous work, which related individual HMW glutenin subunits to bread-making quality by genetical analysis, quality scores were assigned to each of the commonly occurring subunits. The grain proteins of 84 home-grown wheat varieties were fractionated by SDS—PAGE to determine their HMW glutenin subunit composition. The quality scores of each of the subunits were summed to create a Glu-1 quality score for each variety. The results indicated that 47-60% of the variation in the independently established bread-making qualities of this set of varieties could be accounted for by variation in HMW subunits of glutenin. The presence or absence in the varieties of a translocated chromosome, which consisted of the long arm of 1B and the short arm of 1R from rye, was also established because of its known association with poor bread-making quality. A correction factor was applied to the Glu-1 quality score of those varieties that contained the 1 BLURS chromosome. The variations in the rye-adjusted Glu-1 quality scores were compared with those of the bread-making qualities of the varieties, and the proportion of variation in quality accounted for was raised to 55-67%. The Glu-1 quality score and the biscuit-making qualities of the same set of varieties were negatively related. The results are discussed in relation to future strategies recommended to wheat breeders for developing new varieties with improved bread-making quality.