Tag: Protein conversion factor

Approximately 16% of an average protein's weight is nitrogen. Understanding how much nitrogen (%) can be found in 100 grams of protein requires looking at this historical average and the specific amino acid makeup of different protein sources.

Based on research from the 19th century, scientists determined that most proteins contain approximately 16% nitrogen, a discovery that led to the universal practice of multiplying the nitrogen content of feed by 6.25 to estimate its total protein value. This conversion, while widely used, has significant implications for feed analysis and regulatory standards, creating a crucial distinction between 'crude' and 'true' protein measurements.

Developed in 1883, the Kjeldahl method is a standard analytical technique, and central to its calculation is the factor 6.25, but what is 6.25 in the Kjeldahl method and where does this conversion number originate? This factor is the universal average used to convert the nitrogen content of a sample into a crude protein estimate.