| Abstract: | Twelve popular ready‐to‐eat breakfast cereals fortified with folic acid were sampled in the United States in 2006, and the data have been incorporated into the USDA National Nutrient Database for Standard Reference. Cereals were collected from three statistically selected retail outlets in each of four primary census regions, and four composites of each product were prepared using random groupings of three locations each. Folic acid was determined using a validated LC‐MS method, with 13C‐folic acid as an internal standard, after trienzyme treatment and solid phase extraction. A cereal reference material (AACC VMA399) was analyzed as a control. Selected samples were also assayed using the standard microbiological method, with and without trienzyme extraction, to generate an estimate of endogenous folate. On average, as shown on the label, folate content was underestimated. In seven cereals, folate was within 5% of the declared value; in four cereals, it was 5–20% higher; and in two cereals, it was >20% greater, representing –75 to +69 μg/serving (mean 17) of the label value, equivalent to –19% to +17% of the 400 μg/daily value. The microbiologically determined folic acid was higher than LC‐MS by 10–67% (mean 40%). Therefore, use of label values might underestimate folate intake from some breakfast cereals. |
