美藤果油水包油型乳液的制备及其稳定性研究

应用高压匀质法制备美藤果油水包油型乳液。以乳液的平均粒径和分散系数(PDI)为指标,探究Tween乳化剂类型、油质量分数、乳化剂添加量、剪切速率及均质压力对乳液的平均粒径以及PDI的影响。通过测量储藏期内乳液的粒径变化、油相氧化程度(过氧化值和硫代巴比妥酸含量)、液滴的自扩散系数以及游离脂肪酸含量变化,进一步探究储藏期内乳液的物理、氧化以及水解稳定性。结果表明:制备乳液的优化工艺条件为Tween60添加量1%、油质量分数10%、剪切速率16 000 r/min、均质压力40 MPa,此条件下制备的乳液平均粒径为(218. 27±2. 21) nm,PDI为0. 118±0. 002;该工艺条件下制备的美藤果油乳液在14 d的储藏期间内具有较好的耐受pH、盐离子的物理稳定性和较高的氧化稳定性,并且未发生明显的水解作用。     

米酒老面添加量对面团及馒头品质的影响

本文研究了米酒老面添加量(40%、50%、60%、70%和80%)对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明:随着米酒老面添加量的增加,面团pH呈现下降的趋势。米酒老面添加量为60%的面团中湿面筋含量显著低于其他四种添加量(P<0.05),馒头的比容、硬度、白度和感官评分显著高于其他四种添加量(P<0.05)。相关性分析表明,面团pH与馒头的感官评分呈极显著负相关(P<0.01);面团湿面筋含量与馒头比容呈显著负相关(P<0.05),与馒头硬度呈显著正相关(P<0.05),与馒头白度呈极显著负相关(P<0.01)。面团面筋指数与馒头比容呈极显著正相关(P<0.01),与馒头硬度呈极显著负相关(P<0.01),与馒头白度呈显著正相关(P<0.05)。米酒老面的添加会改变面团和馒头的品质,其最适添加量为60%。     

碱添加量对米酒酸面团及馒头品质的影响

该实验研究了碱添加量对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明,碱添加量与pH值呈线性关系。碱添加量为0.20%时,显著降低了面团中湿面筋含量,但提高了面筋指数。碱添加量＞0.20%之后,馒头的感官评分、白度、比容呈现降低趋势,硬度呈现上升趋势。相关性分析结果表明,面团pH值与馒头的比容、白度呈极显著负相关（P＜0.01）;与馒头的感官评分呈极显著正相关（P＜0.01）。面团湿面筋含量与馒头比容呈显著负相关（P＜0.05）,与馒头硬度呈极显著正相关（P＜0.01）。面团面筋指数与面团比容呈显著正相关（P＜0.05）,与馒头硬度呈极显著负相关（P＜0.01）。     

超声-转谷氨酰胺酶改善红豆蛋白功能性质及结构

采用超声联合转谷氨酰胺酶（transglutaminase,TG）处理红豆分离蛋白（red bean protein isolate,RBPI）,对其功能性质和结构特征进行分析,以探究其结构修饰与功能性质的构效关系。结果表明：超声处理5 min能够使RBPI的乳化活性和发泡能力提高,但会降低泡沫稳定性,对乳液稳定性没有显著影响,同时增加表面疏水性和游离巯基含量;TG能够提高RBPI的乳化活性、乳化稳定性及泡沫稳定性,但会降低发泡能力、表面疏水性和游离巯基含量;超声-TG联合处理的RBPI具有更高的乳化活性和泡沫稳定性,更低的表面疏水性和游离巯基含量,且酰胺Ⅰ带处吸收峰强度增加,更多的无规卷曲结构转变为有序的β-折叠结构,这可能是导致RBPI功能性质改善的原因。超声处理5 min联合TG诱导的蛋白凝胶具有更加均匀、致密的微观结构,且凝胶硬度和黏附力增加,脱水收缩作用降低;峰值温度（Tp）和热焓变（ΔH）显著增加（P＜0.05）,改善了RBPI的热稳定性或三级结构稳定性。以上结果表明RBPI经过超声处理后更利于TG对蛋白质的交联作用,超声-TG联合处理促进了蛋白质功能性质的发挥。     

Properties of edible sodium caseinate films and their application as food wrapping

Sodium caseinate solutions (2.5 g protein/100 g solution) containing glycerol (gly) at gly:protein ratios of 0, 0.08, 0.16, 0.24 or 0.32 w/w were dried over 48 h at 50±5% RH and 23±2 °C to form transparent flexible films of approximately 35 μm thickness. Maximum load, tensile strength and elastic modulus of films decreased and the moisture content increased significantly with increasing glycerol content. Elongation and water vapour permeability of films increased significantly only at gly:protein ratios of 0.24 and 0.32. Wrapping bread samples in the caseinate films reduced hardness during 6 h storage at ambient temperatures relative to unwrapped controls. However, the caseinate films were not as effective in this regard as synthetic polyvinyl chloride film.     

Genome shuffling improved acid-tolerance and succinic acid production of Actinobacillus succinogenes

Food Science and Biotechnology - Succinic acid is widely applied to chemical, pharmaceutical, food, and agricultural industries. With the rapid development of these industries, a great demand of...     

Biomass for residential and commercial heating in a remote Canadian aboriginal community

Most residents of Canada's 300 remote communities do not have access to natural gas and must rely upon higher cost and/or less convenient heat sources such as electric heat, heating (furnace) oil, propane, and/or cord wood. This research sought to determine the techno-economic feasibility of increasing biomass utilization for space and hot water heating in remote, off-grid communities in Canada and abroad using a two-option case study approach: 1) a district energy system (DES) connected to a centralized heat generation energy centre fuelled by wood chips; and 2) a decentralized heating option with wood pellet boilers in each individual residence and commercial building. The Nuxalk First Nation Bella Coola community was selected as a case study, with GIS, ground surveys, and climate data used to design DES routes and determine heat demand. It was determined that biomass has the potential to reduce heat costs, reduce the cost of electricity subsidization for electrical utilities, reduce greenhouse gas emissions, and increase energy independence of remote communities. Although results of the analysis are site-specific, the research methodology and general findings on heat-source economic competitiveness could be utilized to support increased bioheat production in remote, off-grid communities for improved socio-economic and environmental outcomes.     

Measuring Corner Properties

We describe methods to measure the following properties of gray level corners: subtended angle, orientation, contrast, bluntness (or rounding of the apex), and boundary curvature (for cusps). Unlike most of the published methods for extracting these properties these new methods are relatively simple, efficient, and robust. They rely on the corner being predetected by a standard operator, thus making the measurement problem more tractable. Using 13,000 synthetic images the methods are assessed over a range of conditions: corners of varying orientations and subtended angles, as well as different degrees of noise.     

A model of combustion chambers,including nitrogen oxide generation,in thermal power plants

In the light of increasing concern related to atmospheric pollution, the cutting of nitrogen oxide emission is one of the fundamental tasks these days in the control design of a thermal power plant. This paper aims at the development of an extended one-dimensional, steady-state model, with nitrogen oxide control in mind, describing the fundamental furnace phenomena. The modelling activity is developed in two steps, on the assumption that the nitrogen oxide generation process has no influence on the overall combustion process. A model of the flame and of the gas fluxes in the combustion chamber is first developed; then the model of the nitrogen oxide production is worked out. In the model, a number of the parameters are uncertain, and are identified from real data by suitable fitting criteria. Validation tests demonstrate the good performance of the model in interpreting experimental data related to nitrogen oxide outlet concentrations.