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%.     

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.     

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四川目前生产的天然气中含硫天然气占７１％，而含硫天然气对高强度钻杆会产生硫化物应力腐蚀玻裂，因此，在含硫气井进行钻杆测试时，应重视钻杆的安全问题。文章探讨了高强度钻杆硫化物应力腐蚀玻裂的机理和影响钻杆脆断时间的各种因素，并提出在一定的条件下，高强度钻杆在含硫气并中进行测试是安全的。采用向钻杆内加缓蚀剂或内涂层钻杆，防硫油管测试，钻杆测试更加安全。建议继续开展高强度钻杆硫化物应力腐蚀玻裂时间的试验研究，以确定合理的钻杆测试安全时间。     

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。     

Compressibility factor model of sweet,sour, and condensate gases using genetic programming

Gas compressibility factor (z-factor) is necessary in most petroleum engineering calculations. The most common sources of z-factor values are experimental measurements, equations of state (EOS) and empirical correlations. There are more than twenty correlations available with two variables for calculating the z-factor from fitting Standing–Katz chart values in an EOS or just through fitting techniques. However, these correlations are too complex, which require initial value and longer computations, and have significant error. This work presents a new model for estimating z-factors of sweet gases, sour gases and gas condensates using genetic programming (GP). The z-factor model was developed using pseudo-reduced pressure, and pseudo-reduced temperature. Moreover, two new models of pseudo-critical pressure and temperature were built as a function of the gas composition (mol percent of C₁–C₇₊, H₂S, CO₂, and N₂) and the specific gravity of the C₇₊. The developed new GP-based model yields a more accurate prediction of gas z-factor compared to the commonly used correlations and EOS's.     

Hydrogen permeation in high strength steel under load in aqueous environment

Abstract

The hydrogen assisted cracking problem is one of the major causes of the failure occurring in the high strength steel structures used in various industries. In aqueous environment, hydrogen is generated by the hydrogen reduction reaction on the steel surface. With depletion of the high quality resources in oil and gas industry, the hydrogen assisted cracking problem becomes severe in sour environment, which contains high amount of H₂S. Understanding on the hydrogen permeation behaviour is crucial to deal properly with the hydrogen related problems since they are primarily determined by the hydrogen uptake and transport in the steel. The Devanathan–Stachurski method is widely used to evaluate electrochemically the hydrogen permeation behaviour. This method has been successfully used for the steel with no load. Under loading condition, this electrochemical test method has been modified to accommodate the externally applied load. However, the data require careful examination to validate the technical importance because of the stability and homogeneity of palladium layer coated on the steel surface under load. In this paper, the hydrogen permeation test method under loading condition will be reviewed for the high strength steels used in oil and gas industry. The factors affecting the hydrogen permeation in the high strength steel will be discussed in terms of the applied stress level and the sulphide film forming on the steel surface in sour environment.     

Effect of packaging materials and storage temperature on the quality of sour cherry nectar

The purpose of this research was to determine the effects of the packaging materials and size on the stability of monomeric anthocyanins, polyphenols, antioxidant activity, ascorbic acid, colour index and hydroxyl methyl furfural (HMF) during the 12‐month shelf life of sour cherry nectars at 4 °C and 20 °C. Sour cherry nectars were aseptically filled out into packaging of different sizes and materials. The packaging included cartons of two different sizes (200 and 1000 mL) and aluminium cans (330 mL). Results showed that the nectars were of better quality when stored at lower temperatures. HMF generally increased significantly for all nectars during storage. Conversely, the total polyphenol content and the antioxidant activity of the nectars stored in aluminium cans and the larger‐sized carton packaging decreased during storage. Lower anthocyanin loss and colour change were found in the nectars stored in aluminium cans. However, the better packaging material was found to be the large‐sized carton package when HMF was analysed.