A Polish team from the Instytut Zywnosci in Warsaw analyzed 22 gluten-free products and 19 naturally gluten-free grains and flours, for gluten content. Gluten content in the products ranged from 5.19 to 57.16 mg/kg. In the inherently gluten-free grains and flours, no gluten was detected in rice and buckwheat samples, but was detected in rice flakes (7.05 mg/kg) in pearl millet (27.51 mg/kg) and in oats (>100 mg/kg). ?(Poland)
Rocz Panstw Zaki Hig. 2010; 61(1):51-5. ??
Meanwhile, in the U.S., Tricia Thompson, MS, RD, a nutrition consultant specializing in gluten-free diets, arranged for gluten-testing of 22 retail samples of inherently gluten-free grains, seeds, and flours. She found contamination of 20 to 2925 ppm in seven of 22 samples, putting them over the proposed FDA limit of 20 ppm, with lower levels in some others. Both articles point to the importance of gluten-free certification even on foods that are naturally gluten-free, such as millet.?(USA)
Journal of the American Dietetic Association. June 2010; 110(6):937-40.