反相高效液相色谱法测定牛奶中的主要蛋白质

建立了测定牛奶中的主要蛋白质的反相高效液相色谱法,对前处理方法进行了优化,采用Agilent Zorbax 300SB-C8(250 mm×4.6 mm,5 μm)色谱柱,三氟乙酸-水-乙腈流动相梯度洗脱,214 nm检测,柱温45 ℃,外标法定量.测定κ-CN, αs2-CN, αs1-CN, β-CN, Whey和Igg的线性关系良好,相关系数均大于0 999,加标回收率在74.8%～132.5%之间.大豆蛋白质不影响分离与检测.采用本方法分析了9种牛奶样品中上述蛋白质的含量与总量,结果表明,本方法测定结果准确可靠.不同样品中4种酪蛋白与乳清蛋白的比例基本接近,但是不同品牌之间存在一定差异.

Determination of Major Bovine Milk Proteins by Reversed Phase High Performance Liquid Chromatography

A RP-HPLC method for the quantification of the six major bovine milk proteins (κ-casein (CN),α_(s2)-CN,α_(s1)-CN,β-CN,Whey,immunoglobulins (Igg) ) is described. Separation and quantification were achieved by a reversed phase analytical column (Agilent Zorbax 300SB-C_8,250 mm×4.6 mm ,5μm) and the gradient elution solvents of 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in acetonitrile at a flow rate of 0. 8 mL/min. Column temperature was set at 45℃ and the sample was monitored with photodiode array detector at 214 nm. A linear relationship( r >0. 999) between the concentrations of proteins and peak areas was observed over the concentration range. Recoveries of six target proteins spiked in milk were form 74. 8% to 132.5%. Nine kinds of milks of different brands were analyzed,and the difference of the concentration and relative ration of κ-CN,α_(s2)-CN,α_(s1)-CN,β-CN and Whey were found.