Gaucheron F, Le Graet Y
INRA, Laboratoire de Recherches de Technologie Laitière, Rennes, France.
J Chromatogr A. 2000 Sep 29;893(1):133-42. doi: 10.1016/s0021-9673(00)00695-6.
To control the quality and the biochemical evolution of milk and dairy products during their technological transformations, it is interesting to determine their ammonium concentrations. A chromatographic method for the determination of this compound is proposed. The method is based on the separation of ammonium by cation-exchange chromatography and its detection by suppressed conductivity. With an appropriate sample preparation, this method enabled identification and quantification of ammonium with good repeatability (relative standard deviation of about 5%). Moreover, good sensitivity (less than 0.5 mg/kg) and no interference between ammonium and other matrix components were determined. It was also shown that this method offers a very promising alternative for studying changes in ammonium concentration of milk or caseinate after their heat treatments and in different dairy products such as yoghurt and cheeses (hard cooked and mould ripened cheeses).
为了在牛奶和乳制品的工艺转化过程中控制其质量和生化演变，测定它们的铵浓度很有意义。本文提出了一种用于测定该化合物的色谱方法。该方法基于通过阳离子交换色谱分离铵，并通过抑制电导检测。经过适当的样品制备，该方法能够以良好的重复性（相对标准偏差约为5%）对铵进行鉴定和定量。此外，还测定出该方法具有良好的灵敏度（低于0.5mg/kg），并且铵与其他基质成分之间无干扰。研究还表明，该方法为研究牛奶或酪蛋白酸盐热处理后以及酸奶和奶酪（硬煮奶酪和霉菌成熟奶酪）等不同乳制品中铵浓度的变化提供了一个非常有前景的替代方法。
