Monitoring Dietary Supplements

February 25/Pharma Business Week -- "The U.S. Food and Drug Administration is studying the need to monitor dietary supplements for mycotoxins such as total aflatoxins and ochratoxin A. An effective mycotoxin-monitoring program requires knowledge of the sampling and analytical variability associated with the determination of total aflatoxins (AF) and ochratoxin A (OTA) in dietary supplements," researchers in the U.S. report.

"Three lots of ginger sold as a powder in capsule form and packaged in individual bottles were analyzed for both AF and OTA. The total variability associated with measuring AF and OTA in powdered ginger was partitioned into bottle-to-bottle, within bottle and analytical variances. The variances were estimated using a nested design. For AF and OTA, the within-bottle variance associated with the 5g laboratory sample size was the largest component of variability, accounting for about 43% and 85% of the total variance, respectively; the analytical variance accounted for about 34% and 9% of the total variability, respectively; and the bottle-to-bottle variance accounted for about 23% and 7% of the total variance, respectively," wrote M.W. Trucksess and colleagues, Food & Drug Administration.

The researchers concluded, "When the total variance is converted into the coefficient of variation (CV or standard deviation relative to the mean concentration), the CV is lower for AF (16.9%) than OTA (24.7%)."

Trucksess and colleagues published their study in the Journal of Agricultural and Food Chemistry ("Sampling and Analytical Variability Associated with the Determination of Total Aflatoxins and Ochratoxin A in Powdered Ginger Sold As a Dietary Supplement in Capsules." Journal of Agricultural and Food Chemistry, 2009;57(2):321-325).

For additional information, contact M.W. Trucksess, Food & Drug Administration, College Park, MD, USA.

From the February 16, 2009, Prepared Foods E-dition