基于氨基酸模式的牛奶蛋白掺假分析
Adulteration analysis of milk protein based on amino acid pattern
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摘要: 以市售合格牛奶及奶粉为材料,采用面粉及淀粉对其进行模拟掺假,通过柱前衍生化-高效液相色谱法(HPLC)对样品中的色氨酸(Trp)、苏氨酸(Thr)、缬氨酸(Val)、赖氨酸(Lys)进行检测,建立判别牛奶蛋白掺假的氨基酸简洁模式。结果表明,建立的牛奶氨基酸模式为:色氨酸∶苏氨酸∶缬氨酸∶赖氨酸=1.0∶2.7∶3.5∶5.4,与世界卫生组织(WHO)提出的牛乳标准氨基酸模式吻合;奶粉氨基酸模式为:色氨酸∶苏氨酸∶缬氨酸∶赖氨酸=1.0∶3.0∶4.5∶5.4;掺假牛奶、奶粉的氨基酸模式与上述氨基酸模式相比有明显差异。利用柱前衍生化-高效液相色谱法建立牛奶及奶粉的氨基酸简洁模式可有效判别出牛奶及奶粉的蛋白掺假,能满足常规检测及乳品的安全控制需要。Abstract: To establish a method for identifying of milk protein adulteration based on amino acid pattern. With on sale qualified milk and milk powder as material, flour and starch were used to simulate adulteration. Tryptophan (Trp) , threonine (Thr) , valine (Val) and lysine (Lys) of the samples were determined by pre-column derivation-high performance liquid chromatography (HPLC) to establish amino acid concise patterns for identifying milk protein adulteration. The result indicated that the amino acid pattern of qualified milk was Trp∶Thr∶Val∶Lys=1.0∶2.7∶3.5∶5.4, which was highly anastomosed with the standard one proposed by World Health Organization (WHO) . And the amino acid pattern of qualified milk powder was Trp∶Thr∶Val∶Lys=1.0∶3.0∶4.5∶5.4. The amino acid patterns of adulterate milk and milk powder were significantly different from these of qualified ones. In conclusion, it was feasible to apply amino acid concise patterns of milk and milk powder to analyze milk protein adulteration, and this method could meet the requirements of routine determination and food safety control of dairy.