The USDA National Nutrient Database for Standard Reference (SR) is the major source
of food composition data in the United States. It provides the foundation for most
food composition databases in the public and private sectors. As information is
updated, new versions of the database are released. This version, Release 21 (SR21),
contains data on 7,412 food items and up to 140 food components. It replaces SR20
issued in September 2007.
Data have been compiled from published and
unpublished sources. Published sources include the scientific literature. Unpublished
data include those obtained from the food industry, other government agencies, and
research conducted under contracts initiated by USDA’s Agricultural Research Service
(ARS). These analyses are currently conducted under the National Food and Nutrient
Analysis Program (NFNAP), in cooperation with the National Cancer Institute and
16 other offices and institutes of the National Institutes of Health (Pehrsson et
al., 2000). Data from the food industry represents the nutrient content of a specific
food or food product at the time the data is sent to NDL. The values may change
due to reformulations or other processing changes by individual companies between
the time that SR is released and the next update of this database. Values in the
database may be based on the results of laboratory analyses or calculated by using
appropriate algorithms, factors, or recipes, as indicated by the source code in
the Nutrient Data file. Not every food item contains a complete nutrient profile.