Texturized Dairy Proteins

ABSTRACT: Dairy proteins are amenable to structural modifications induced by high temperature, shear, and moisture; in particular, whey proteins can change conformation to new unfolded states. The change in protein state is a basis for creating new foods. The dairy products, nonfat dried milk (NDM), whey protein concentrate (WPC), and whey protein isolate (WPI) were modified using a twin-screw extruder at melt temperatures of 50, 75, and 100 °C, and moistures ranging from 20 to 70 wt%. Viscoelasticity and solubility measurements showed that extrusion temperature was a more significant (P < 0.05) change factor than moisture content. The degree of texturization, or change in protein state, was characterized by solubility (R²= 0.98). The consistency of the extruded dairy protein ranged from rigid (2500 N) to soft (2.7 N). Extruding at or above 75 °C resulted in increased peak force for WPC (138 to 2500 N) and WPI (2.7 to 147.1 N). NDM was marginally texturized; the presence of lactose interfered with its texturization. WPI products extruded at 50 °C were not texturized; their solubility values ranged from 71.8% to 92.6%. A wide possibility exists for creating new foods with texturized dairy proteins due to the extensive range of states achievable. Dairy proteins can be used to boost the protein content in puffed snacks made from corn meal, but unmodified, they bind water and form doughy pastes with starch. To minimize the water binding property of dairy proteins, WPI, or WPC, or NDM were modified by extrusion processing. Extrusion temperature conditions were adjusted to 50, 75, or 100 °C, sufficient to change the structure of the dairy proteins, but not destroy them. Extrusion modified the structures of these dairy proteins for ease of use in starchy foods to boost nutrient levels. Practical Application: Dairy proteins can be used to boost the protein content in puffed snacks made from corn meal, but unmodified, they bind water and form doughy pastes with starch. To minimize the water binding property of dairy proteins, whey protein isolate, whey protein concentrate, or nonfat dried milk were modified by extrusion processing. Extrusion temperature conditions were adjusted to 50, 75, or 100 °C, sufficient to change the structure of the dairy proteins, but not destroy them. Extrusion modified the structures of these dairy proteins for ease of use in starchy foods to boost nutrient levels.     

Fatty acid composition of muscle fat and enzymes of storage lipid synthesis in whole muscle from beef cattle

Enhanced intramuscular fat content (i.e., marbling) in beef is a desirable trait, which can result in increased product value. This study was undertaken with the aim of revealing biochemical factors associated with the marbling trait in beef cattle. Samples of longissimus lumborum (LL) and pars costalis diaphragmatis (PCD) were taken from a group of intact crossbred males and females at slaughter, lipids extracted, and the resulting FAME examined for relationships with marbling fat deposition. For LL, significant associations were found between degree of marbling and myristic (14∶0, r=0.55, P<0.01), palmitic (16∶0, r=0.80 P<0.001), stearic (18∶0, r=−0.58, P<0.01), and oleic (18∶1c-9, r=0.79, P<0.001) acids. For PCD, significant relationships were found between marbling and palmitic (r=0.71, P<0.001) and oleic (r=0.74, P<0.001) acids. Microsomal fractions prepared from PCD muscle were assayed for diacylglycerol acyltransferase (DGAT), lysophosphatidic acid acyltransferase (LPAAT), and phosphatidic acid phosphatase-1 (PAP-1) activity, and the results examined for relationships with degree of intramuscular fat deposition. None of the enzyme activities from PCD displayed an association with marbling fat content, but DGAT specific activity showed significant positive associations with LPAAT (r=0.54, P<0.01), total PAP (r=0.66, P<0.001), and PAP-1 (r=0.63, P<0.01) specific activities. The results on FA compositions of whole muscle tissues provide insight into possible enzyme action associated with the production of specific FA. The increased proportion of oleic acid associated with enhanced lipid content of whole muscle is noteworthy given the known health benefits of this FA.     

Application of AFM from microbial cell to biofilm

Atomic Force Microscopy (AFM) has proven itself over recent years as an essential tool for the analysis of microbial systems. This article will review how AFM has been used to study microbial systems to provide unique insight into their behavior and relationship with their environment. Immobilization of live cells has enabled AFM imaging and force measurement to provide understanding of the structure and function of numerous microbial cells. At the macromolecular level AFM investigation into the properties of surface macromolecules and the energies associated with their mechanical conformation and functionality has helped unravel the complex interactions of microbial cells. At the level of the whole cell AFM has provided an integrated analysis of how the microbial cell exploits its environment through its selective, adaptable interface, the cell surface. In addition to these areas of study the AFM investigation of microbial biofilms has been vital for industrial and medical process analysis. There exists a tremendous potential for the future application of AFM to microbial systems and this has been strengthened by the trend to use AFM in combination with other characterization methods, such as confocal microscopy and Raman spectroscopy, to elucidate dynamic cellular processes. SCANNING 32: 134–149, 2010. © 2010 Wiley Periodicals, Inc.     

iPhone出奇“智”胜系列——爱疯又爱聊

在这新新人类的社会里,人人都喜爱在网络中聊天,不管是与同学胡乱调侃、与另一半传达爱意,还是与同事召开网络会议。生活中,我们都离不开它。在家聊天可以靠电脑,但是出门在外,想聊个QQ或是MSN的话,该怎么办呢？这时候“爱疯”的“疯子”肯定会说“用iPhone嘛!”没错,iPhone作为以服务和程序为重点的手机产品,相关的聊天工具怎么可能会少呢？     

用单个按钮实现多种功能

如果你拥有一部智能电话（例如,BlackBerry、Palm…等）、个人数字助理（PDA）、笔记本电脑或PC,那么你也许已经熟悉了用单一按钮就可以利用的多种电源功能。这些设备仅是这类例子中的几个,在这类设备中,用来给设备加电和断电的主按钮常常具有附加功能,通常是“备用”或“冬眠”模式,这种模式将设备置于一种省电模式。在笔记本电脑中,当你暂时离开时,备用模式切断对硬盘驱动器和显示屏的供电,将数据存储到存储器中,保持笔记本电脑基本部分的运行。在冬眠模式,笔记本电脑完全停机,将数据保存到硬盘驱动器而不是存储器中,     

蓝青蛙酒廊与录音棚

Serie建筑师事务所是一个国际化事务所,涉及的领域包括建筑、城市的设计。事务所关注于当代城市中建筑类型的进化和变异以及这些智慧形式在空间解决方案上的应用。类型学式的研究,或者用他们的名词,“连续”（SERIES）的思考和探索（利用建筑类型的累积智慧）是Serie作品的关键。     

Support for a full program: Last year's lessons on company conflict resolution efforts resonate

Gerald F. Phillips , of Los Angeles, organized an American Bar Association company ADR program session for a conference last year, and attended another. The sessions demonstrated results, and the experiences resonated. He describes what was discussed, and why the messages delivered need to be spread for better business productivity.     

An investigation of the aerodynamic admittances and aerodynamic weighting functions of trains

Increasing train speeds combined with the predicted reduction in the weight of new trains ensure that the effect of crosswinds on train stability is of continued interest to the rail industry. Changes in the approaching wind velocity can in turn lead to changes in both the lift and side force on a vehicle. Calculations of the wind induced force can either be undertaken in the frequency domain with knowledge of aerodynamic admittance characteristics or in the time domain using aerodynamic weighting functions. This paper investigates the applicability of developing a universal aerodynamic admittance function and a corresponding analytical weighting function for a variety of train types based on a range of experimental data. It is suggested that only two variables are required to parameterise both the admittance and weighting functions. It is also argued that for certain train types one of these variables can be considered as a constant across a wide range of yaw angles.