Tag: Nitrogen to protein conversion

Protein typically contains an average of 16% nitrogen by weight, a fact that forms the basis for many calculation methods in food science. To accurately determine the protein content in food, researchers and manufacturers employ several standardized analytical techniques that measure nitrogen or other protein-specific properties.

Dating back to the 19th century, a standard assumption was made that proteins contain 16% nitrogen. This led to the creation of the factor 6.25 when calculating protein content, a conversion that remains in widespread use today for nutritional labeling and laboratory analysis.

Food manufacturers determine protein content by measuring a food’s nitrogen level and multiplying it by a conversion factor. This indirect measurement, while a universal standard, comes with limitations that can lead to slight inaccuracies in the final calculated value. Understanding the various laboratory techniques reveals why some methods are more precise than others for calculating the protein content in food.