Crude Protein is a measure of how much protein is in food, based on laboratory tests studying the food’s chemical composition. When you look for protein content on a food’s nutrition label, the number you see refers to crude protein.
- There are two types of protein measurement: crude protein and true protein. Crude protein is measured by calculating the nitrogen levels in food. Since protein is made up of amino acids and amino acids contain nitrogen, the total nitrogen content in food allows us to estimate the total protein level. When looking at nutrition labels, the protein content is typically expressed using the crude protein measurements.
- High protein content and high nutritional value.
- There’s some evidence that the facts listed on menus don’t accurately report the actual nutrient — including protein — content of the food. One study, published in Appetite in 2015, found that the actual protein content of restaurant food offered on a college campus differed significantly from the nutrition info posted on the menu. In addition, the real protein content of milk can differ from the amount of crude protein, according to a report from Cornell University. This difference can have a significant effect on making dairy products, like cheese, notes the report.
Source: LiveStrong, http://www.livestrong.com/article/519702-what-is-crude-protein/