乳蛋白作为食品配料的价值与应用

通过对乳蛋白质体系的组成、结构、营养和物理化学性质的分析，阐述乳蛋白的价值以及富含优质蛋白的乳制品作为蛋白性配料的应用。同时介绍一些特殊乳蛋白如乳铁蛋白、免疫球蛋白等的市场前景。     

乳蛋白肽及其在食品中的应用

结合乳蛋白肽的生物活性，讨论了其在婴儿配方粉、运动员食品以及医疗食品中的应用。     

婴幼儿配方食品和乳粉中乳清蛋白的测定

国家质量技术监督局最近通过并制定婴幼儿配方食品和乳粉中营养素的国家标准,并将于今年9月1日实施。本文将介绍《婴幼儿配方食品和乳粉乳清蛋白的测定》(GB/T 5413.2-1997)。     

婴儿配方乳粉的配方设计与制作

婴儿配方乳粉又称母乳化奶粉,是专供六个月以内婴儿食用的母乳代用品。其配方有四种类型:①以牛乳为主要原料;②以牛乳和乳清为主要原料;③以大豆蛋白为主要原料;④以蛋白质水解物为主要原料。目前我国大多数生产单位都采用以牛乳为主,添     

婴儿配方食品中添加牛磺酸的探讨

一、前言自Hayer等1975年发现幼猫因牛磺酸缺乏导致视网膜退化而失明后,从此确定了牛磺酸的营养作用。十几年来,众多的学者对牛磺酸的生理功能及营养学作用进行了广泛地研究。1978年Gaull发现,生长发育中的动物大脑中牛磺酸含量显著高于成年动物大脑中该物质的含量。动物实验表明,牛磺酸具有促进大鼠大脑及智力发育作用,表现在学习、记忆能力上的提高。用母乳喂养的婴儿血浆及尿中牛磺酸浓度都维持在较高的     

低温微滤技术制备富含β-酪蛋白和乳清蛋白的新型功能性乳蛋白配料

以市售的巴氏杀菌脱脂乳为原料,探究膜孔径、温度、洗滤液和洗滤次数等条件对β-酪蛋白和乳清蛋白分离效果和膜通量的影响,最终制备了富含β-酪蛋白与乳清蛋白的新型功能性乳蛋白配料。研究采用聚丙烯酰胺凝胶电泳和高效液相色谱对蛋白做定性和定量分析。研究表明,在4℃条件下,使用30 nm孔径的陶瓷膜,以水作为洗滤液,可使得β-酪蛋白的分离效果最佳;在最优条件下,脱脂乳经微滤浓缩3倍后,再在相同条件下补水洗滤4次,将膜过滤各阶段所得的透过液混合,可得到β-酪蛋白和乳清蛋白的产率分别为51.7%和99.7%,复合蛋白中β-酪蛋白和乳清蛋白所占比例分别为51.1%和40.0%,而αs-酪蛋白的含量得以大大降低,该功能性复合蛋白可作为一种新型的功能性蛋白配料用于配方乳粉等婴幼儿食品的研制。     

干混法婴儿配方乳粉脂肪氧化问题的研究

本文阐述的实验，查明了干混法生产的婴儿配方乳粉，短期内出现脂肪氧化的原因，并提出有效的解决办法。     

乳铁蛋白的功能特性及其在婴儿配方奶粉中的应用

介绍了母乳中乳铁蛋白的功能特性，及其应用在婴儿配方奶粉中对非母乳喂养婴儿营养的重要性，国外有关乳铁蛋白在婴幼儿配方奶粉中的应用情况。探讨了乳铁蛋白在婴儿配方奶粉中应用的研究过程，包括有关配方设计依据、使用的原料、生产工艺流程、检验方法、检验结果等。     

高效液相色谱法测定婴幼儿配方奶粉中酪蛋白磷酸肽含量

目的建立高效液相色谱法(highperformanceliquidchromatography,HPLC)测定婴幼儿配方奶粉中酪蛋白磷酸肽(casein phosphopeptide, CPP)的含量的方法。方法对样品静置温度、静置时间、沉淀分离方式进行优化,用高效液相色谱法对婴幼儿配方奶粉中CPP的含量进行测定。结果最优的前处理条件为样品溶解后调整pH至4.6,于4℃条件下静置1 h,过滤后上清液经0.22μm滤膜过滤,以Ultimate AQ-C_(18)色谱柱(250mm×4.6mm,5μm)分离。经钼蓝比色法鉴定,保留时间为8.387min的组分为CPP。该方法在10～1000mg/L范围内线性关系良好,相关系数为0.9993,定量限为4.40 mg/L,婴幼儿奶粉中添加量为500、1000、5000 mg/kg时, CPP的回收率为96.63%%～101.42%。结论该方法样品前处理简单,稳定性和可靠性良好,检测结果符合定性定量要求,可用于婴幼儿配方奶粉中CPP含量的测定。     

液态乳制品中乳清蛋白和酪蛋白含量分析

随着居民对乳制品消费能力的提升,消费者对乳制品的品质提出了更高的要求,乳中功能蛋白因其重要的生物学功能成为研究热点。该实验采集13种风味发酵乳和风味酸乳以及15种其他液态乳制品,共计28个样品,采用高效液相色谱-串联质谱法测定28种液态乳制品中乳清蛋白和酪蛋白的含量。结果显示,不同来源、不同加工方式液态乳制品中乳清蛋白和酪蛋白的含量存在一定差异,鲜牛奶和纯牛奶中乳清蛋白和酪蛋白的含量普遍高于风味发酵乳和风味酸乳。该文评价了28种液态乳制品中乳清蛋白和酪蛋白的差异性,以期分析不同加工方式对乳品中功能蛋白含量的影响,为消费者购买高品质液态乳制品提供数据支撑。     

Invited review: Microfiltration-derived casein and whey proteins from milk

Milk, a rich source of nutrients, can be fractionated into a wide range of components for use in foods and beverages. With advancements in filtration technologies, micellar caseins and milk-derived whey proteins are now produced from skim milk using microfiltration. Microfiltered ingredients offer unique functional and nutritional benefits that can be exploited in new product development. Microfiltration offers promise in cheesemaking, where microfiltered milk can be used for protein standardization to improve the yield and consistency of cheese and help with operation throughputs. Micellar casein concentrates and milk whey proteins could offer unique functional and flavor properties in various food applications. Consumer desires for safe, nutritious, and clean-label foods could be potential growth opportunities for these new ingredients. The application of micellar casein concentrates in protein standardization could offer a window of opportunity to US cheese makers by improving yields and throughputs in manufacturing plants.     

牛羊乳蛋白组分比较研究

羊乳被国际营养学界誉为"奶中之王",逐渐被人们列为日常生活的营养保健佳品。该文对羊乳和牛乳的蛋白组分(主要是酪蛋白和乳清蛋白)含量、氨基酸组成及变异体等方面的差异进行了综述,并且对两者酪蛋白胶束的差异进行了比较,为羊乳检验和加工提供理论依据。     

膜技术在乳品工业中的应用

综述膜的设计及结构,以及膜技术在乳品工业中应用的研究进展。随着膜技术的发展以及人们对乳成分知识的深入了解,膜技术在液态乳的除菌、乳蛋白的分离、干酪的加工、乳清的处理、初乳的处理,乃至干酪盐水及废水处理与纯化等方面的应用日益广泛。膜技术将为提高乳制品质量、新产品开发、提高生产效率及增加产品利润提供新的途径,成为在不破坏乳成分的前提下保证乳制品安全的强有力的加工手段。     

Symposium review: Characterization of the bovine milk protein profile using proteomic techniques

Identification and characterization of the comprehensive bovine milk proteome has historically been limited due to the dichotomy of protein abundances within milk. The high abundance of a select few proteins, including caseins, α-lactalbumin, β-lactoglobulin, and serum albumin, has hindered intensive identification and characterization of the vast array of low-abundance proteins in milk due to limitations in separation techniques and protein labeling capacity. In more recent years, the development and advancement of proteomics techniques have yielded valuable tools for characterization of the protein profile in bovine milk. More extensive fractionation and enrichment techniques, including the use of combinations of precipitation techniques, immunosorption, gel electrophoresis, chromatography, ultracentrifugation, and hexapeptide-based binding enrichment, have allowed for better isolation of lower abundance proteins for further downstream liquid chromatography–tandem mass spectrometry approaches. The different milk subfractions isolated during these processes can also be analyzed as individual entities to assess the protein profile unique to the different fractions—for instance, investigation of the skim milk-associated proteome versus the milk fat globule membrane-associated proteome. Updates to high-throughput methods, equipment, and software have also allowed for greater interpretation and visualization of the data. For instance, labeling techniques have enabled analysis of multiplexed samples and more accurate comparison of specific protein abundances and quantities across samples, and integration of gene ontology analysis has allowed for a more in-depth and visual representation of potential relationships between identified proteins. Inclusively, these developments in proteomic techniques have allowed for a rapid increase in the number of milk-associated proteins identified and a better grasp of the relationships and potential functionality of the proteins within the milk proteome.     

The balance between caseins and whey proteins in cow's milk determines its allergenicity

Cow's milk allergy is quite common in the first years of human life. Protein composition plays an important role in this pathology, particularly the casein/whey protein ratio. It is known that milks from different species have different sensitization capacities although their protein sources are quite similar. Thus, the objective of this work was to compare the allergenicity of native cow's milk and milk with a modified ratio of casein and whey proteins in a murine model of atopy. Twenty-four Balb/c mice were orally sensitized to native cow's milk or modified cow's milk with a casein/whey protein ratio of 40:60. During the sensitization period, the number of mice suffering from diarrhea was significantly higher in the native cow's milk-sensitized group than in the modified milk-sensitized group. Once mice were killed, plasma histamine levels were shown to be significantly higher in native cow's milk-sensitized mice. In addition, cow's milk proteins induced a higher lymphocyte sensitization in the native milk-sensitized mice, with a significant increase in the specific proliferation ratio of these cells.These results suggest that the balance between caseins and whey proteins plays an important role in the sensitization capacity of cow's milk, and its modification might be a way to reduce the allergenicity of cow's milk.     

Milk Proteins Affect Yield and Sensory Quality of Cooked Sausages

Sausages were produced with seven different mixtures with skim milk powder, sodium caseinate and whey protein (1.5, 3, 5%) according to a simplex-centroid design, where the proportion of each ingredient varied from 0 to 100%. Principal component analysis (PCA) identified that sausages with 1.5% milk protein were most similar in sensory quality to the controls and had minimum cooking loss. PCA was effective to reduce the number of attributes to five to describe the main variation among the 1.5% milk protein sausages. A mixture of 1:1 blend of skim milk powder and whey protein resulted in the product with lowest cooking loss.     

Invited review: Microbial evolution in raw-milk,long-ripened cheeses produced using undefined natural whey starters

The robustness of the starter culture during cheese fermentation is enhanced by the presence of a rich consortium of microbes. Natural starters are consortia of microbes undoubtedly richer than selected starters. Among natural starters, natural whey starters (NWS) are the most common cultures currently used to produce different varieties of cheeses. Undefined NWS are typically used for Italian cooked, long-ripened, extra-hard, raw milk cheeses, such as Parmigiano Reggiano and Grana Padano. Together with raw milk microbiota, NWS are responsible for most cheese characteristics. The microbial ecology of these 2 cheese varieties is based on a complex interaction among starter lactic acid bacteria (SLAB) and nonstarter lactic acid bacteria (NSLAB), which are characterized by their different abilities to grow in a changing substrate. This review aims to summarize the latest findings on Parmigiano Reggiano and Grana Padano to better understand the dynamics of SLAB, which mainly arise from NWS, and NSLAB, which mainly arise from raw milk, and their possible role in determining the characteristics of these cheeses. The review is presented in 4 main sections. The first summarizes the main microbiological and chemical properties of the ripened cheese as determined by cheese-making process variables, as these variables may affect microbial growth. The second describes the microbiota of raw milk as affected by specific milk treatments, from milking to the filling of the cheese milk vat. The third describes the microbiota of NWS, and the fourth reviews the knowledge available on microbial dynamics from curd to ripened cheese. As the dynamics and functionality of complex undefined NWS is one of the most important areas of focus in current food microbiology research, this review may serve as a good starting point for implementing future studies on microbial diversity and functionality of undefined cheese starter cultures.