Casein Peptization, Functional Properties, and Sensory Acceptance of Processed Cheese Spreads Made with Different Emulsifying Salts

ABSTRACT:  " Requeijão cremoso " is a traditional Brazilian processed cheese spread, showing ample acceptance on the national market. Emulsifying salts (ES) are an important factor influencing the characteristics of processed cheeses, but the literature presents conflicting results about their action on cheese functionality.  Requeijão cremoso  obtained from anhydrous ingredients allows the study of the influence of each type of ES on the cheese properties, since it can be treated as a model system where the variables are limited and well known. The objective of this study was to evaluate the effect of different types of ES (TSC—sodium citrate, SHMP—sodium hexametaphosphate, STPP—sodium tripolyphosphate, and TSPP—tetrasodium pyrophosphate) on the sensory and functional characteristics of  requeijão cremoso -processed cheeses obtained from anhydrous ingredients. The physicochemical composition, degree of casein dissociation, fat particle size, melting index, color, texture profile, and sensory acceptance of the cheeses were determined. The functional behavior of processed cheeses was strongly influenced by the type of ES and its physicochemical properties including its ability to bind Ca, the casein dispersion during cooking, and the possible creation of cross-links with casein during cooling. The cheese made with SHMP was the one most differentiated from the others, presenting lower melting index, whiter color, and higher values for hardness, gumminess, and adhesiveness. The differences in texture had an impact on sensory acceptance: with the exception of the sample manufactured with sodium hexametaphosphate, all the samples presented good sensory acceptance.     

Comparative post‐harvest behaviour of traditional and virus‐resistant Muchamiel tomatoes

BACKGROUND: Nowadays, organoleptic quality is the primary objective for almost all tomato breeding programmes. In this study, post‐harvest behaviour of a breeding line with genetic resistance to important viruses (tomato mosaic virus, tomato spotted wilt virus and tomato yellow leaf curl virus) has been compared with the original traditional landrace (Muchamiel). The breeding line has been obtained by backcrossing, introgressing three resistance genes but aiming to keep the quality characteristics of the traditional variety. Tomatoes were picked at random and stored at 10 °C for 13 days. Quality analyses were made in both tomato samples: weight loss, colour, respiration rate, ethylene production, maturity index, instrumental hardness and sensory evaluation with trained panel. RESULTS: Fruits of the breeding line were characterized by higher hardness even with a higher maturity index. Results of sensory tests were in agreement with instrumental measurements. Organoleptic quality of Muchamiel virus‐resistant tomatoes was at least as high as that of traditional tomatoes, reaching the best scores in odour and aroma at the 13th storage day. CONCLUSION: Although a long time has been required to develop the breeding line, results indicate that organoleptic fruit quality has been recovered through backcrossing, confirming the success of the breeding programme. Copyright © 2010 Society of Chemical Industry     

Effect of high pressure processing on wheat dough and bread characteristics

Microbial, physical and structural changes in high pressured wheat dough were studied as a function of pressure level (50-250 MPa) and holding time (1-4 min). Thereafter, selected conditions of high hydrostatic processing (HPP) were applied to bread dough and the technological quality of the obtained breads was studied. The effect of HPP on wheat dough was investigated by determining microbial population (total aerobic mesophilic bacteria, moulds and yeasts), color and mechanical and texture surface related dough parameters (cohesiveness, adhesiveness, hardness and stickiness). HPP reduced the endogenous microbial population of wheat dough from 10⁴ colony forming units/g (CFU) to levels of 10² CFU. HPP treatment significantly (P < 0.05) increased dough hardness and adhesiveness, whereas treatment time reduced its stickiness. Scanning electron micrographs suggested that proteins were affected when subjected to pressure levels higher than 50 MPa, but starch modification required higher pressure levels. HPP treated yeasted doughs led to wheat breads with different appearance and technological characteristics; crumb acquired brownish color and heterogeneous cell gas distribution with increased hardness due to new crumb structure. This study suggests that high hydrostatic processing in the range 50-200 MPa could be an alternative technique for obtaining novel textured cereal based products.     

表面复杂几何纹理的机械加工技术

介绍了表面复杂几何纹理在各种工业制品及日常用品的外观装饰上的再现与应用,并从现代加工技术的可行性角度,提出一套操作性较强且制造成本可接受的具体应用技术,实现用机械加工工艺对表面复杂几何纹理的高保真纹理映射。同时,提出与其相应的检测,仿真复现等方面的实用操作工艺。     

胖大海胶对猪肉糜品质的影响

以胖大海的中层皮层吸水胀润后形成的胶状物为研究对象,研究了胖大海胶对猪肉内糜蒸煮损失、色泽、质构及感官品质的影响.结果表明:胖大海胶的加入可明显减小肉糜的蒸煮损失,提高肉制品产率,且与胖大海胶的加入量和加入方式有关,0.2％的胖大海胶溶解后加入效果最好;胖大海胶的加入对内糜色泽有一定的影响:亮度减弱,红度和黄度有所增加;质构方面,胖大海胶可减小肉糜的硬度和咀嚼性,增大其弹性,感官评价结果基本与质构测定一致.     

An analytical approach for analysis and optimisation of slider bearings with infinite width parallel textures

This paper introduces an analytical approach to study the textured surfaces in hydrodynamic lubrication regime. For this purpose, a method of integrating the Reynolds equation for slider bearings with surface discontinuities is presented. By introducing appropriate dimensionless parameters, analytical relations for various texture profiles in both indented and projected forms are delivered. These relations express the nature of mathematical dependence between textured bearing performance measures and geometrical/operational parameters. An optimisation procedure is employed to achieve the optimum texturing parameters promoting maximum load capacity, load capacity to lubricant flow rate ratio and minimum friction coefficient for asymmetric partially textured slider bearings.     

分形在信息处理中的应用

分形是一门新兴的信息数学理论,具有广泛的应用价值。文中对分形原理及其实现算法做了分析和研究,阐述了其迭代函数系,总结了分形在信息处理中的一些应用。并利用分形吸引子对一些图形、数据等信息进行了处理。仿真实验表明,运用分形方法来处理信息可以有效地获得原始信息的纹理特征。     

基于SIFT的图像建模算法研究

为解决飞行或航海模拟器中建模手段单一、真实感较差等问题,研究了基于SIFT的图像建模算法.该算法针对目前图像建模算法中存在的人工参入图像匹配负担较大问题,实现了基于尺度不变特征的图像自动匹配;针对重建物体视觉外观真实感较差问题,采用了图像融合算法首先对纹理图像进行处理,然后再进行纹理映射的方法.实验结果表明,算法具有较好的鲁棒性,生成的三维模型准确真实,较之以往算法具有建模简单、操作方便,真实感强的特点.     

电解电容器高压阳极用高纯铝箔织构研究

采用蚀坑法、EBSD微观取向分析法,研究了电解电容器高压阳极用高纯铝箔制备过程中的织构演变。结果表明:热轧高纯铝板织构主要类型是高斯织构、立方织构和铜织构。随着冷轧变形率的增加,冷轧织构中的立方织构含量增加,冷轧变形率为96.3%时,立方织构体积分数为14%。再结晶织构中的立方织构含量随再结晶退火温度的增加而增加,再结晶退火温度为530℃时,立方织构体积分数为86%。     

一种基于图形处理器的压缩单纯形方法

 针对GPU通用计算环境CTM纹理资源的限制,研究了一种适于CTM的单纯形方法.依据单纯形方法每次变换最多只增加一列非单位元向量和矩阵求逆运算的特征,给出GPU上系数矩阵、基逆矩阵等的压缩存储策略及在该策略下求解基逆矩阵、单纯形乘子和检验数等步骤新的计算规则.CPU主要进行迭代控制;而计算密集类任务皆由GPU完成.理论分析证明该方法比标准方法在时空复杂度上提高了一个数量级.数值实验表明该方法不仅扩大了可求解问题的规模,且在获得正确优化结果的前提下,效率比CPU版本有数百倍的提高,甚至数倍领先于MATLAB R2007a.