通过LTQ Orbitrap XL 组合型傅里叶变换高分辨质谱与反相高效液相色谱技术联用建立了南方水牛奶酪蛋白和大豆蛋白主要组分肽质指纹图谱，并对其氨基酸组成与序列进行了比较．结果表明:酪蛋白经胰蛋白酶酶解后得到的 28 个肽段中没有检测到与酶解大豆分离蛋白 181 个肽段相匹配的肽段;酪蛋白(CN)的主要组分是α_s1 - CN、β- CN、κ-CN，大豆蛋白的主要组分为大豆球蛋白(包括大豆球蛋白 G1 ～ G5 亚基)和 β 伴大豆球蛋白(α，α'，β 链);水牛奶酪蛋白和大豆蛋白在亚基组分的氨基酸数量、组成比例和排列方式均呈现出明显的差异，大豆蛋白的各组分亚基的氨基酸全序列均大于酪蛋白各组分的氨基酸全序列，且大豆蛋白各组分的分子质量均显著高于酪蛋白各组分．LTQ Or-bitrap XL 质谱技术对乳源蛋白肽质指纹的分析，为今后鉴定分析牛奶蛋白中是否添加廉价蛋白提供了高精度和高准确度的检测方法，也为复杂混合物中的痕量组分检测提供了理论依据．

Peptide mass fingerpringting spectra of south buffalo milk casein and soybean protein were established byusing a LTQ Orbitrap XL mass spectrometer combined with RP- HPLC techniques,and the corresponding aminoacid sequences were compared.The results indicate that,among the 28 detected peptides fractions obtained by thetryptic hydrolysis of α_s1 - CN,β- CN and κ- CN originated from south buffalo milk caseins,no fraction matches withthe 181 peptides fractions from the glycinin (glycinin G1 ～ G5 subunit) and the β- conglycinin (α,α',β subunit) ofsoybean protein components,Moreover,it is found that there exists great differences in the number,composition ra-tio and arrangement patterns of amino acid subunits between south buffalo milk caseins and soybean protein compo-nents,and that the full amino acid sequence of soy protein subunits is longer than that of casein amino acid compo-nents,the molecular mass of each component of soy protein is significantly higher than that of the components of ca-sein.The adopted LTQ Orbitrap XL mass spectrometry technique for analyzing the peptide mass fingerprint of milk-derived protein provides a high- precision tool for identifying cheap proteins in milk protein and lays a reliable theo-retical foundation for the detection of trace components in complex mixture.