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主题:【原创】三鹿事件的一个疑问和一个担忧 -- 抱朴仙人

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家园 【原创】我来帮仙人做个简单计算吧

从质检总局官方网站上表2 理化指标

外链出处

每100克奶粉中蛋白质应该是12-18克

从联合国粮农组织网站上关于蛋白质含氮量的分析大致是16%

外链出处

For many years, the protein content of foods has been determined on the basis of total nitrogen content, while the Kjeldahl (or similar) method has been almost universally applied to determine nitrogen content (AOAC, 2000). Nitrogen content is then multiplied by a factor to arrive at protein content. This approach is based on two assumptions: that dietary carbohydrates and fats do not contain nitrogen, and that nearly all of the nitrogen in the diet is present as amino acids in proteins. On the basis of early determinations, the average nitrogen (N) content of proteins was found to be about 16 percent, which led to use of the calculation N x 6.25 (1/0.16 = 6.25) to convert nitrogen content into protein content.

所以按照国家标准,12-18克蛋白质含氮量是1.92-2.88克.

三鹿是2563毫克三聚氰胺每千克, 相当于0.2563克三聚氰胺每100克奶粉.

三聚氰胺(C3H6N6)含氮量是6*14/(12*3+6+6*14)=66.67%. 所以0.2563克三聚氰胺含氮量是0.171克.

换算成蛋白质是1.068克,也就是说5.9%-8.9%的蛋白质是用三聚氰胺顶替的。

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