共查询到18条相似文献，搜索用时 218 毫秒
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随着消费者对A2 β-酪蛋白的关注度提升,A2 β-酪蛋白相关产品不断更新换代。A2 β-酪蛋白常用检测方法有反相高效液相色谱法（RP-HPLC）、液相色谱–高分辨串联质谱法、毛细管区带电泳法、试剂盒检测法等。本文对β-酪蛋白遗传变体A1 β-酪蛋白和原始形态A2 β-酪蛋白的功能特点、检测方法、定量分析进行综述,说明检测方法的原理和试剂药品的作用机理,加强对A1 β-酪蛋白、A2 β-酪蛋白检测方法的改进与优化,为A2 β-酪蛋白应用于功能性食品、婴幼儿配方食品提供理论依据。 相似文献
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[目的]研究生乳蛋白质稳定性评价方法、稳定性体系评价模型。[方法]通过酒精试验、煮沸试验、热冲击试验、安定度试验、磷酸盐试验的原理、检验方法、结果判定、优缺点的研究分析,建立生乳蛋白质稳定性综合评价方案,及酒精、煮沸、热冲击、安定度、磷酸盐试验等多项指标。利用数字化工具建立蛋白质稳定性评价模型。通过模型分析判定生乳的使用等级,提高优质原料生乳的准确使用率。[结果]模型评价生乳质量,高效准确。[结论]通过质量评价数据共享,指导牧场提升生乳品质,以及乳制品加工厂分级使用,准确用于加工不同类型的产品。 相似文献
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为比较九龙藏黄牛和九龙牦牛β-酪蛋白（β-CN）的遗传变异体,试验采用酸性尿素聚丙烯酰胺凝胶电泳分析了九龙藏黄牛（n=42）和九龙牦牛（n=17）β-CN的基因型。结果表明,在九龙藏黄牛、九龙牦牛的β-CN中共检测到4 种等位基因,包括A1、A2、B、C,其中在九龙藏黄牛中有7 种基因型：A1A1、A1A2、BB、A1B、A2B、A1C、BC,优势等位基因为A1（频率0.702 4）,优势基因型为A1A1（频率0.547 6）;在九龙牦牛样本中有2 种基因型：A1A2、A2A2,优势等位基因为A2（频率0.764 7 ）。试验表明,九龙藏黄牛与九龙牦牛β-CN均表现出多态性,但优势等位基因明显不同。 相似文献
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酪蛋白占牛奶总蛋白80%,具有很高的营养价值和重要的生理功能。A1和A2型β-酪蛋白是牛奶中两种主要的β-酪蛋白遗传变异体。牛奶A2型β-酪蛋白和人乳中的β-酪蛋白结构和消化特点相似,对人体更亲和,也更容易被消化吸收。开发A2型牛奶对增加乳制品品种、细分乳制品市场、提高乳制品档次具有积极意义。本文介绍了牛奶β-酪蛋白基因多态性、中国荷斯坦牛群β-酪蛋白基因型频率和等位基因频率、A2奶牛和A2牛奶的检测、以及A2乳制品开发现状,并对新疆开发A2牛奶及乳制品提出意见和建议。 相似文献
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[目的] 建立同时测定蒙古族传统奶酪中VA、VD2、VD3、α-生育酚、β-生育酚、γ-生育酚、δ-生育酚、VK1共8种脂溶性维生素及天然色素β-胡萝卜素含量的高效液相色谱方法（high performance liquid chromatography,HPLC）。[方法] 选取蒙古族传统奶酪为试样,经无水乙醇提取,酶解后用正己烷萃取,旋蒸浓缩,复溶过滤膜。经Agilent poroshell 120 EC-C18（150 mm×4.6 mm,4 μm）色谱柱分离,以甲醇和水（体积比为95∶5）为流动相,采用FLD和VWD检测器检测,外标法定量。[结果] VA、α-生育酚、β-生育酚、γ-生育酚、δ-生育酚、VK1、β-胡萝卜素在0.1~1.0 μg/mL浓度范围内线性关系良好,VD2、VD3在0.05~1.00 μg/mL浓度范围内线性关系良好,相关系数R2均大于0.998。[结论] 建立的HPLC方法具有简便、快捷、灵敏度高、回收率高、分析时间短等优点,可为蒙古族传统乳制品中多种脂溶性维生素及天然色素的快速检测提供技术支撑。 相似文献
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奶牛被称为“人类的保姆”,牛奶是能为人类提供最优质、最完善的营养物质之一。而乳中蛋白质直接决定着乳制品的品质和风味。研究发现乳中蛋白质主要有两类：酪蛋白和乳清蛋白,两者占乳中蛋白质总量的95％,酪蛋白包括αS1,酪蛋白（αS1-CN）、αS2-酪蛋白（αS2-CN）、β-酪蛋白（β-CN）、 κ-酪蛋白（κ-CN）;乳清蛋白包括α-乳清蛋白（α-La）、 相似文献
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牛αS1酪蛋白基因变异及其与生产性状的关系 总被引：1，自引：0，他引：1
αS1酪蛋白是牛乳中含量最高的蛋白,其基因的多态类型会影响奶牛的产奶性状和牛乳的一些加工特性,人们已经对其进行了广泛研究.牛αS1酪蛋白基因编码区全长17 508 bp(不计启动子序列),由19个外显子和18个内含子构成,外显子与内含子长度比例为1∶14.4.尽管其编码区突变率较高,但侧翼序列比较保守.到目前为止,牛αS1酪蛋白共发现有9种变异体,由核苷酸非同义替换、插入或缺失及外显子跳跃造成.牛αS1酪蛋白蛋白质序列及DNA序列的高度差异性揭示其编码基因可能是一个高速进化的基因家族.αS1酪蛋白基因与泌乳性状之间的关联性可以用基因调控区,特别是转录因子结合位点存在突变位点来解释.但是,有关牛αS1酪蛋白基因变异体还存在一些未探明的结果,因此,阐明其基因的结构特点并进一步揭示它们与生产性状之间的关系是非常必要的. 相似文献
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Denise R. Freitas Leorges M. Fonseca Fernando N. Souza Cristiane V. G. Ladeira Soraia A. Diniz João Paulo A. Haddad Diêgo S. Ferreira Mônica M. O. P. Cerqueira 《Animal Science Journal》2015,86(5):553-556
Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitable to cheese production. 相似文献
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N. A. Poulsen A. K. Rosengaard B. D. Szekeres V. R. Gregersen H. B. Jensen L. B. Larsen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2016,66(4):190-198
A proteomic approach was applied to characterize genetic variation and relative protein content of β-casein (β-CN) in milk from two minor native dairy breeds in Denmark; Red Danish 1970 and Jutland cows in comparison to the major dairy breeds; Danish Holstein and Danish Jersey. Genetic β-CN variants were related to the relative concentration of β-CN. Furthermore, a very high frequency of variant F in the native breeds was found. This was remarkable as this variant is only found in a very low frequency in the major Danish breeds. Novel associations were found between β-CN variant F and milk coagulation properties in the native breeds, which is an important finding for understanding the genetic background for non- and poor coagulating milk and potential exploitation of β-CN variants in selective breeding programs. Furthermore, in Red Danish 1970 a very high prevalence of non-coagulating milk was found (18%). 相似文献
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Peciulaitiene N Miseikiene R Baltrenaite L Miceikiene I 《Polish journal of veterinary sciences》2007,10(1):35-41
The intrabreed and interbreed genetic diversity of Lithuanian cattle breeds - two native, namely Lithuanian Light Grey and Lithuanian White-Backed and two modern, namely Lithuanian Red and Lithuanian Black and White was investigated by determination of genetic markers: 4 milk protein systems, Alpha(s1)-casein, Kappa-casein, Beta-casein and Beta-lactoglobulin, which are comprised of 12 different milk protein types. According to results, the B type of Alpha(s1)-casein was found as predominant in all four studied breeds. The most common A and B types of Kappa-casein were found at high frequency in all investigated cattle breeds. All investigated Lithuanian dairy cattle breeds had high frequency of Beta-lactoglobulin whey protein B types, with the highest frequency in Lithuanian Red breed, and the lowest in Lithuanian Light Grey. After investigation the diversity of alleles and genotypes of milk proteins in Lithuanian dairy cattle breeds was determined that, Lithuanian Red breed was distinguished private C allele and BC genotype of Beta-lactoglobulin and CC genotype of Alpha(s1)-casein. The interbreed genetic diversity was estimated by a principal component analysis (PCA). The first principal component (PC) explains 63.39% and the second principal component (PC) explains 33.67% of the genetics diversity between the breeds. Principal component analysis, suggests the hypothesis that native Lithuanian White Backed and Lithuanian Light Grey breeds still have traits tracing to old native populations. 相似文献
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近年来我国乳品消费量持续增加,乳品质量安全关乎着人们身体健康和生命安全.金黄色葡萄球菌及其肠毒素引起的乳品中毒事件时有发生,逐本求源地针对原料乳开展金黄色葡萄球菌风险评估研究是十分必要的.本文根据国际食品法典委员会拟定的微生物风险评估的原则和指导方针,从危害识别、危害特征描述、暴露评估、风险描述四方面综述了关于原料乳中金黄色葡萄球菌国内外风险评估的研究现状.通过国外成熟的定量风险评估案例,介绍关于原料乳中金黄色葡萄球菌定量风险评估的基本框架,提出未来应加强构建肠毒素预测模型,较为系统的对原料乳从牧场到餐桌进行全程监控和风险评估的建议. 相似文献