DEVELOPMENT OF ACCURATE AND REPRESENTATIVE FOOD COMPOSITION DATA FOR THE U.S. FOOD SUPPLY
Location: Nutrient Data
Title: QUALITY CONTROL MATERIALS IN THE USDA NATIONAL FOOD AND NUTRIENT ANALYSIS PROGRAM (NFNAP)
Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 12, 2006
Publication Date: January 12, 2006
Citation: Phillips, K., Patterson, K.K., Rasor, A., Exler, J., Haytowitz, D.B., Holden, J.M., Pehrsson, P.R. 2006. Quality control materials in the usda national food and nutrient analysis program (nfnap). Analytical and Bioanalytical Chemistry. 384:1341-1355.
Interpretive Summary: The National Food and Nutrient Analysis Program (NFNAP) was initiated by NDL to update and improve the quantity and quality of data in USDA nutrient database products. One of the principal aims of NFNAP calls for the analysis of samples with a rigorous quality control (QC) program. The QC protocol includes a selection process for choosing competent laboratories, as well as ongoing assessment of each laboratory’s analytical performance. The QC needs of the NFNAP are unique due to the need to coordinate work among multiple commercial laboratories along with a number of university researchers, the analysis of many types of nutrients and foods, and the number of years the project spans. Work among multiple sites is coordinated to achieve NFNAP goals from sample procurement through data dissemination. This approach is necessary since the USDA does not have an analytical facility dedicated to the receipt, processing, and analysis of the number of samples required for the NFNAP. The Food Analysis Laboratory Control Center (FALCC) at Virginia Polytechnic Institute and State University in Blacksburg, Virginia was selected to fulfill this role in the project because they had considerable experience in doing this sort of work. A critical component of the NFNAP QC program is the development of an extensive array of food-based control materials specifically for the NFNAP, which are used along with commercially available certified reference materials. The objective of this paper is to discuss the development and use of these control materials to facilitate monitoring the accuracy and precision of analyses conducted as part of the NFNAP. The importance of submitting independent, blinded, food specific control samples along with test samples to contract laboratories to validate analytical results and provide comprehensive analytical quality control is illustrated. This work has resulted in the generation of high-quality food composition data which has been used to update and expand the data in the USDA National Nutrient Database for Standard Reference, the foundation of many public and private food composition databases in the United States and internationally, along with a number of special interest tables.
The U.S. Department of Agriculture (USDA) Nutrient Data Laboratory (NDL) develops and maintains the USDA National Nutrient Databank System (NDBS). Data are released from NDBS for scientific and public use through the USDA National Nutrient Database for Standard Reference (SR) (www.nal.usda.gov/fnic/foodcomp). In 1997 NDL initiated the National Food and Nutrient Analysis Program (NFNAP) to update and expand its food composition data. The program included: 1) nationwide probability based sampling of foods; 2) central processing and archiving of food samples; 3) analysis of food components at commercial, government, and university laboratories; 4) incorporation of new analytical data into the NDBS; and 5) dissemination of these data to the scientific community. A key feature and strength of the NFNAP was a rigorous quality control program that permitted independent verification of the accuracy and precision of analytical results. Custom-made food control composites and/or commercially available certified reference materials were sent blinded to the laboratories along with the samples. Data for these materials were essential to ongoing monitoring of analytical work and to the identification and resolution of suspected analytical problems, to assure the accuracy and precision of results for the NFNAP food samples.