FTIR光谱法和杜马斯燃烧法联用鉴定奶粉品质

Identification of Milk Powder Quality by the FTIR Spectroscopy and the Dumas Combustion Method

我国现行标准GB 5009.5-2016《食品中蛋白质的测定》中的杜马斯(Dumas)燃烧法是先将样品燃烧测出含氮量,然后根据氮元素与蛋白质换算系数计算蛋白质的含量,如果添加含氮量高的物质,如三聚氰胺,就可以测出较高的"蛋白质含量"。采用普通FTIR光谱定性鉴别出奶粉的主要组成成分,然后用杜马斯燃烧法准确测出奶粉中的氮元素和碳元素含量,通过蛋白质换算系数计算出蛋白质含量,可以避免上述由于添加违规化学物质造成测定蛋白质含量虚高的结果;同时通过C/N元素含量比,进一步印证奶粉中的营养成分组成。

The Dumas combustion method in the current standard GB 5009.5—2016'determination of protein in food'is to measure the nitrogen content of the sample first,and then calculate the protein content according to the conversion coefficient of nitrogen and protein.If those substances with high nitrogen contents are added,such as melamine,it can be used to measure the higher Protein content.In this paper,the main components of the milk powder are identified by the common FTIR spectrum,and the contents of nitrogen and carbon in the milk powder are accurately measured by the Dumas combustion method,and the protein content is calculated by the conversion coefficient of protein.At the same time,the nutrient compositions of milk powder were further confirmed by C/N element content ratio.