Abstract: A liquid chromatographic (LC) method was established for the determination of α-casein, β-casein, κ-casein, α-lactalbumin and β-lactoglobulin in ultra high temperature (UHT) milk. The proteins in milk were denatured by adding a buffer solution containing bis[tris(hydroxymethyl)aminomethane (BisTris), guanidine hydrochloride, sodium citrate, dithiothreitol, etc. The analytes were detected by an ultraviolet (UV) detector and quantified by the external standard method. The results showed that the calibration curve of each protein had good linearity with a correlation coefficient above 0.995. The recoveries of spiked samples were between 95.2% and 105.0%, the detection limit was 0.01–0.02 g/100 mL, and the relative standard deviation was 0.78%–2.70%. The method is characterized by good separation effect, good repeatability and simple operation, and is suitable for quantitative analysis of α-casein, β-casein, κ-casein, α-lactalbumin and β-lactoglobulin in UHT milk.

Key words: ultra high temperature milk; α-casein; β-casein; κ-casein; α-lactalbumin; β-lactoglobulin; protein content; liquid chromatography

摘要： 建立一种超高温（ultra high temperature，UHT）灭菌乳中α-酪蛋白、β-酪蛋白、κ-酪蛋白、α-乳白蛋白及β-乳球蛋白含量的液相色谱检测方法。采用含双[三(羟甲基)氨基甲烷]、盐酸胍、柠檬酸钠、二硫苏糖醇等的缓冲液及试剂使蛋白溶解变性，运用液相色谱仪紫外检测器进行检测，外标法定量。结果表明：各蛋白标准曲线线性良好，相关系数在0.995以上，加标回收率为95.2%～105.0%，检出限为0.01～0.02 g/100 mL，相对标准偏差为0.78%～2.70%。该方法具有分离效果好、重复性好、操作简便的特点，适用于UHT灭菌乳中α-酪蛋白、β-酪蛋白、κ-酪蛋白、α-乳白蛋白及β-乳球蛋白的定量分析。

关键词: 超高温灭菌乳；α-酪蛋白；β-酪蛋白；κ-酪蛋白；α-乳白蛋白；β-乳球蛋白；蛋白含量；液相色谱法