Using Wheat Starch in Gluten-Free Foods
In the US we are not used to seeing wheat starch in gluten-free food. This may be changing. Schar* has introduced their wheat starch-based croissants to the US market. This may lead other manufacturers of gluten-free foods to follow suit. As you make a personal decision whether to eat these products, you may want to keep the following points in mind:
1. In the U.S. wheat starch is allowed in food labeled gluten-free.
2. The Food and Drug Administration considers wheat starch an ingredient processed to remove gluten.
3. Wheat starch contains varying amounts of gluten.
a. A recent study found wheat starch to contain from less than 5 parts per million of gluten to over 10,000 parts per million of gluten (1).
4. Individuals with gluten-related disorders should eat wheat starch and wheat-starch containing products only if they are labeled gluten-free.
5. Manufacturers who choose to use wheat starch in their products should make sure the wheat starch is represented by the supplier as gluten-free and containing less than 20 parts per million of gluten.
6. Wheat starch should be tested using both the sandwich and competitive R5 ELISAs.
a. R-biopharm recommends using the competitive R5 ELISA to test starch (2).
b. The competitive R5 ELISA is used when gluten has been partially hydrolyzed.
c. Gluten in wheat starch may be partially broken down during processing (1).
7. Current testing methods for gluten contamination are not perfect.
8. The R5 ELISA detects the prolamin gliadin.
a. Gluten is made up of prolamins and glutelins; in wheat the prolamin is gliadin and the glutelin is glutenin.
b. The gliadin value is multiplied by 2 to determine the level of gluten.
c. In general, the gliadin to glutenin ratio is considered to be 1:1.
d. However in reality this ratio is variable.
e. In one recent study the ratio varied from 0.31 to 3.19 in wheat starch samples (1).
f. The ratio was less than 1 in seven out of fifteen wheat starch samples (meaning that the gluten content was underestimated) (1).
g. Researchers concluded, “The considerable variation of gliadin to glutenin ratios confirmed the need for a reliable, non-immunochemical analytical method capable of accurately quantitating both gliadin and gluten in wheat starch samples to ensure the safety of gluten-free foods for coeliac disease patients.” (1)
Bottom Line: If you choose to eat foods made from wheat starch make sure:
1.The product is labeled gluten-free.
2.The manufacturer and/or supplier are testing wheat starch for gluten using both the sandwich and competitive R5 ELISAs.
Note: Gluten Free Watchdog has completed testing on wheat starch and foods containing wheat starch using both the sandwich and competitive R5 ELISAs. As was expected, wheat starch not labeled gluten-free contained higher levels of gluten and gluten fragments than wheat starch labeled gluten-free. Nonetheless, wheat starch labeled gluten-free contained small levels of both intact and hydrolyzed gluten.
For a listing of products tested please click HERE. Test results are available to subscribers of GFWD.
*Note: Because of R-biopharm’s recommendation to test wheat starch with the competitive R5 ELISA, GFWD has been in communication with Schar regarding testing.
Statement from Schar regarding their testing protocol:
“Dr. Schar has a long-standing experience in gluten testing as Dr. Schär adheres to the strictest gluten thresholds since more than 30 years. Every product batch is tested to assure the compliance with the legal treshold of 20 ppm. Before Dr. Schar introduced certified gluten free wheat starch the potential suppliers were thoroughly tested with all available validated test methods and in collaboration with the leading test kit manufacturers to assure the security of the products containing gluten free wheat starch. Finally the supplier with the most effective gluten removal technology and the best sensoric results was chosen to guarantee the same high standard for wheat starch containing gluten free products. Schär tested all Gluten Free Croissant batches with both the sandwich and competitive R5 ELISAs and all results were below 20 ppm gluten. Schar will regularly test croissants using both the sandwich and competitive R5 ELISAs per the recommendation of R-biopharm.”
1. Proceedings of the 27th Meeting Working Group on Prolamin Analysis and Toxicity. Analytical Research Reports. Katharina Konitzer, Herbert Wieser, Peter Koehler. German Research Centre for Food Chemistry, Leibniz Institute, Freising, Germany. Quantitation of gluten in wheat starch by gel permeation chromatography with fluorescence detection Available at: http://www.wgpat.com/proceeding_27th.html
2. R-biopharm. Ridascreen Gliadin Competitive. Available at: http://www.r-biopharm.com/wp-content/uploads/items/ridascreen-gliadin-competitive-4493/R7021-Gliadin-competitive-10-12-06-1.pdf
© Copyright April 2015 by Tricia Thompson, MS, RD for Gluten Free Watchdog. All Rights Reserved. Updated October 14, 2015.