Nitrogen analysis protein shake on crude protein or dry matter?
The protein percentage in your protein shake that is indicated on the label is not always correct, as you have noticed in the meantime. This is quite certainly always lower by using another trick, amino spiking is not necessary if you can do magic with numbers. Hocus pocus i measure the dry matter!, without moisture so that the protein percentage becomes higher on paper. Protein powders are not completely dry and contain approximately 4-5% moisture. So in some cases, if there is a manufacturer versed in the magic arts 4 to 5% of the indicated protein magically appears.
The protein content on dry matter is not of use for the consumer. How much protein there really is in your whey, that's what you want to know. Luckily, there are companies that take the moisture content into account and calculate on crude protein. Unfortunately, this is not a common practice, but a simple yet clear nitrogen analysis can make this trick quickly fail. This allows the curtain to fall quickly for the whey magician in question.
Here you can see how the manufacturer transforms the crude protein measurement into dry matter (droge stof). There has been found a crude protein (ruw eiwit) content of 76.3%. The moisture (vocht) will be extracted by warming up the whey in order to measure on dry substance. In this case they have calculated the moisture and you can calculate back to dry matter.
If a manufacturer only indicated the value on dry matter it can be easily recalculated to crude protein. On average, you can count fo 5% moisture.
80 grams / 100 grams of protein on dry matter = 80%
80 / (100 + 5) x 100 = 76.2% crude protein, as it is in you whey protein.