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United States Department of Agriculture

Agricultural Research Service


Location: Nutrient Data Laboratory

Title: The History and Current Status of Protein Measurement in the USDA National Nutrient Database for Standard Reference

item Patterson, Kristine - Kris
item Holden, Joanne

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/11/2009
Publication Date: 6/17/2009
Citation: Patterson, K.K., Holden, J.M. 2009. The history and current status of protein measurement in the USDA National Nutrient Database for Standard Reference. U.S. Pharmacopeia Meeting, Food Protein Workshop, June 16-17, 2009, Rockville, Maryland.

Interpretive Summary:

Technical Abstract: For more than 110 years the US Department of Agriculture (USDA) has disseminated nutrient data on the protein content of foods. The current data on nutrient content of foods is in the National Nutrient Databank which is maintained and updated by the Nutrient Data Laboratory that is part of the USDA's Agricultural Research Service. This database provides the foundation for most other U.S. food composition database applications, including the databases for the U.S. What We Eat in America: NHANES and for epidemiological applications. Protein data in this database have come from a variety of sources including the food industry, scientific literature, other government agencies, USDA studies, and from imputation from other data using recipes and algorithms. Through a collaboration with the U.S. National Institutes of Health, USDA has developed the National Food and Nutrient Analysis Program (NFNAP) to generate original analytical data for important foods. Protein is not analyzed directly in foods. Nitrogen is determined and protein is estimated using nitrogen-to-protein conversion factors. Depending on the amino acid composition of the food and the presence of non-protein nitrogen components, the factor may vary with the type of food. For labeling purposes the Food and Drug Administration has set the default factor at 6.25. As a result, data provided by industry will generally use that factor regardless of the type of food. Nitrogen data from NFNAP for commodity-level foods are converted to protein using Jones factors, when available for the particular food, that take into account the sources of the nitrogen giving a more accurate estimation of protein content. For a multi-component food, the default factor is used. Data from the National Nutrient Databank is disseminated to the public annually on the internet as the USDA National Nutrient Database for Standard Reference.

Last Modified: 10/18/2017
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