Combined effects of wheat gluten and carboxymethylcellulose on dough rheological behaviours and gluten network of potato–wheat flour-based bread

Incorporating high level of potato flour into wheat flour enhances nutritional values of bread but induces a series of problems that lead to the decline of the bread quality. To overcome the barrier, wheat gluten and carboxymethylcellulose (CMC) were added into potato–wheat composite flour to improve dough machinability and bread quality. The rheological properties, thermo-mechanical properties and microstructures of dough were investigated. The results showed that the interaction between gluten and CMC mitigated the discontinuity of gluten matrix and gluten protein aggregation caused by the addition of potato flour, which yielded a more branched and compact gluten network. The compact three-dimensional viscoelastic structure induced improvements of gas retention capacity and dough stability, making it mimic the machinability properties of wheat flour dough. Bread qualities were apparently improved with the combined use of 4% gluten and 6% CMC, of which specific volume increased by 42.86%, and simultaneously, hardness reduced by 75.93%.     

Origin and practical significance of the sticky dough factor in 1BL/1RS wheats

When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, β‐glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water‐soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non‐1BL/1RS doughs. Significant genotype–environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non‐1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high‐speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture. © 2002 Society of Chemical Industry     

Dough mixing and breadmaking properties of quinoa-wheat flour blends

Flour blends of quinoa-wheat containing 0, 5, 10, 15, and 20% of manually dehulled quinoa meal or flour were evaluated for dough mixing and breadmaking properties and liking of the bread by a small panel. Increasing amounts of quinoa meal or flour increased farinograph absorption and dislike of bread for most of the panel. Dough development time increased with increase in meal but decreased with increase in quinoa flour. At 10% inclusion levels differences in liking from control 100% wheat flour bread were smaller for flour or water extracted meal to most of the panel, than with 10% non-extracted meal. This suggests that 10% inclusion of flour or water extracted meal may have potential for further investigation.     

《盲杖第1部分:安全色标志》国家标准色度性能和光度性能指标的确定

以标准GB 16930.1-1997《盲人手杖安全色标志》为基础,参考GB 2893-2008《安全色》、GB/T 18833-2012《道路交通反光膜》等标准,选择国内外不同企业生产的30种反光膜样品,针对其色度性能和光度性能进行试验验证,包括色度坐标范围、亮度因数和最小逆反射系数.综合考虑盲杖使用者的实际出行特点、产品特性、国内行业现状、使用安全性,确定盲杖安全色标志逆反射材料色度性能和光度性能的技术指标.为修订强制性国家标准GB 16930.1《盲杖第1部分:安全色标志》提供数据支持.     

面皮快餐食品工业化生产的调查及工艺研究

通过对面皮传统手工制作工艺的调查分析,提出了面皮工业化生产的工艺和方法,进而对面皮作为方便快餐食品的开发进行了论述。利用先前开发的面皮机和小麦淀粉厂的有关设备,进行了中试试验,在此基础上提出了有关工艺和经济技术指标。     

玉米种皮膳食纤维对面团流变学特性及饺子皮品质的影响

采用粉质仪和拉伸仪研究了不同添加量玉米种皮膳食纤维面团的粉质拉伸特性和质构特性,采用物性测试仪(TPA)研究了不同添加量玉米种皮膳食纤维对制作的生饺子皮和熟饺子皮质构的影响.结果表明:玉米种皮膳食纤维的添加,使面团的吸水率增大、形成时间与稳定时间显著延长、弱化度下降;使面团的拉伸曲线面积、抗拉伸阻力和拉伸比例增大,面团延伸性变小;使生饺子皮硬度和黏附性减小,其弹性、内聚性、胶凝性、咀嚼性和回复性增大,熟饺子皮黏附性减小,硬度、弹性、胶凝性、咀嚼性和回复性增大,内聚性基本不变.     

玉米粉的品质改良

玉米作为主食材料其淀粉呈多角形,蛋白质中缺少醇溶谷蛋白,不能形成粘弹性面团,限制了其应用,产品形式较少,口感较粗糙。对玉米粉进行改性处理,使其具有与小麦粉类似的加工性质,从而开发更多的产品,充分利用玉米的营养,扩大玉米粉的应用范围,改善产品的食用品质。     

Weight loss of frozen bread dough under isothermal and fluctuating temperature storage conditions

Evaporative weight loss from food leads to both loss of saleable weight and quality deterioration so it need to be minimized. The effect of isothermal and fluctuating conditions on frozen dough weight loss was measured and compared with kinetic, physical and artificial neural network (ANN) models. Frozen dough samples were regularly weighed during storage for up to 112 days in loose-fitting plastic bags. The storage temperatures were in the range of −8 to −25 °C with fluctuations of ±0.1 °C (isothermal), ±1, ±3 or ±5 °C about the mean. For each combination of temperature and fluctuation amplitude, the rate of dough weight loss was constant. The rate of weight loss at constant temperature was nearly proportional to water vapour pressure consistent with standard theories for evaporative weight loss from packaged foods but was also accurately fitted by Arrhenius kinetics. Weight loss increased with amplitude of temperature fluctuations. The increase could not be fully explained by either the physic model based on water vapour pressure differences or the kinetic model alone. An ANN model with six neurons in the input layer, six neurons in hidden layers and one neuron in the output layer, achieved a good fit between experimental and predicted data for all trials. However, the ANN model may not be accurate for product, packaging and storage systems different to that studied.