Compilers' Toolbox™ - Non-Protein Nitrogen

Non-Protein Nitrogen in Foods

	Updated 2021-03-29

Apart from protein, foods and feeds contain many other nitrogenous compounds. These non-protein nitrogenous compounds are of interest, because the do not show any protein effect. As protein in foods is most often measured by determining the foods' nitrogen content, it is of great nutritional interest to adjust then total nitrogen content ("crude" nitrogen) found. This is done by subtracting the measured non-protein nitrogen from total nitrogen. Only the

The non-protein nitrogenous compounds include a long range of compounds like free amino acids, purines, pyrimidine, nucleotides, peptides, urea, ammonia compounds, e.g. biogenic amines, phospholipids, creatine/creatinine, nitrate/nitrite and many other compounds.

The amount of non-protein nitrogen varies immensely between different foods from almost none to more than 50% of the nitrogen content.

References

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Non-Protein Nitrogen in Foods