There are many way of aminospiking. In order to be able to defend ourselves against them, it is essential to understand the logic behind.
Out of the macronutritients (protein, carbohydrate, fat), only protein contains nitrogen, what’s more, in a fairly constant ratio. Therefore, conventional protein tests actually measure only the nitrogen content of a product, and calculate the supposed protein content out of that.
Many unfair manufacturers have recognized this loophole: if hey add extra nitrogen to the product, then the apparent protein content will also rise and the product can be sold for a higher price (as it is of “higher quality” – they say)