Confusing Ingredients in the Gluten-Free Diet

It depends. Past testing of blue cheese containing mold spores grown on gluten-containing materials has been done by the Canadian Celiac Association. Results were < 5 ppm gluten.

However, more recent testing shows that it is possible that barley enzymes may sometimes contain enough barley protein to be a problem for individuals with celiac disease.

Choose blue cheese labeled gluten free. As an extra precaution, until more is known, it may be best to avoid products containing or using barley enzymes unless the final product is tested for residual gluten using a competitive ELISA (a test for gluten contamination).4 Contact the manufacturer directly to ask these questions.

For more information, read “Gluten-free labeling: are growth media containing wheat, barley, and rye falling through the cracks” (See article below in References)

Caramel is a coloring agent that may be made from a variety of sources including malt syrup and starch hydrolysates, such as wheat starch hydrolysates. However, caramel is most often made from cornstarch.

Distilled alcohol is an alcoholic liquor made from distillation of wine or other fermented fruit or plant juice, or from a starchy material (such as various grains) that has first been brewed.

Regardless of whether distilled alcohol is made from wheat, barley, or rye it is considered gluten free. For detailed information, please see the section on alcohol.

Glucose syrup is a starch hydrolysate that is sometimes made from wheat starch or barley starch. For products sold in the US, this ingredient is most likely made from cornstarch.

Dextrose is simply another word for glucose. It is considered gluten free regardless of the starting material. 

This is a flavoring ingredient that is usually made from barley. It may be listed as malt, malt flavoring, malt extract, or malt syrup.

Any product containing malt is not gluten free, and must be avoided. 

Maltodextrin is a starch hydrolysate that may be made from wheat starch but is usually made from cornstarch, especially in the US.

Regardless of the starting material, maltodextrin is considered gluten free. Even if wheat or barley is listed as the source, it is highly unlikely that it would cause an otherwise gluten-free food to contain 20 ppm or more gluten.

Most often this ingredient is made from corn. If it is derived from wheat starch, modified food starch may not be gluten free.

On FDA-regulated products sold in the U.S. if modified food starch is derived from wheat, it will be clearly listed either in the ingredients list or in a “Contains” statement (or both). If wheat is not listed in either place, modified food starch can be considered gluten free.

In USDA-regulated products containing wheat-based modified food starch, wheat may not be stated on the label. If modified food starch is listed, and the product does NOT have a gluten free label, it may be best to contact the manufacturer to ask about the source of their starch.

These are fats used as chemical binding agents.

Monoglycerides and diglycerides do not contain gluten, though occasionally wheat may be used as a "carrier." If so, wheat will be listed in the ingredients list or the "Contains" statement (or both) on an FDA-regulated package.

MSG is a flavor enhancing food additive. It is the salt of the amino acid glutamic acid. 

Various starches and sugars may be used as starting materials but wheat starch does not appear to be one of them. Even if it was, it is highly unlikely that the salt of glutamic acid would contain traces of gluten. 

While the FDA has classified MSG as a food ingredient that is "generally recognized as safe," it is a controversial ingredient. Anecdotal reports of symptoms from sensitivity to MSG include headache, flushing, sweating, nausea, and weakness, etc. However, these reactions do not have anything to do with gluten.

Natural flavors are products from any one of numerous sources of plant material or animals whose primary function is to flavor food.

Most likely. Unless wheat, barley, rye, or malt are included in the ingredients list or “Contains” statement (or both) of a product containing natural flavor, the natural flavor is most likely free of gluten.

Rice syrup or brown rice syrup is a liquid sweetener made from rice. Enzymes are added to the rice to break down the starch into sugar. These enzymes are sometimes derived from barley.

Unclear. Past testing done on barley enzymes and products made using barley enzymes found them to contain < 5ppm gluten. However, more recent testing shows that it is possible that barley enzymes may sometimes contain enough barley protein to be a problem for individuals with celiac disease. Until more is known, it may be best to avoid products containing or using barley enzymes unless the final product is tested for residual gluten using a competitive ELISA (a test for gluten contamination). Contact the manufacturer directly to ask these questions.

For more information, read Gluten-free labeling: are growth media containing wheat, barley, and rye falling through the cracks (See the article below in References).

In general, seasonings are blends of flavoring agents (e.g. spices, herbs, hydrolyzed wheat protein, smoke flavoring) and sometimes an anticaking agent such as (calcium silicate). These are often combined with a carrier agent (e.g. salt, sugar, lactose, whey powder, starch or flour). Wheat starch, wheat flour and malted barley flour are common carrier agents in seasoning blends.16 Any spices, flavoring, or colorings included in the seasoning may be listed collectively but all other ingredients (including the carrier agent) must be named in a sub-ingredient list.

It depends. If the word “seasonings” in an ingredient list does not include a sub-ingredient list, it is best to avoid the product because it is likely incorrectly labeled. If the words wheat, barley, rye, or malt are not in the subingredient list, the seasoning probably does not contain gluten.

Smoke flavoring is flavoring derived from burning various types of woods.

It depends. “When used as an ingredient in a food product, dry smoke flavoring may sometimes use barley malt flour to capture the smoke. It is not known at this time how often this occurs or how much gluten smoke flavoring may contain.”1 This is not a concern if the product is labeled gluten free.

Contact the manufacturer if you have concerns about this ingredient.

Sugar alcohols rarely may be derived from glucose syrup that is derived from wheat starch or barley starch.

Sugar alcohols are considered gluten free regardless of the starting materials so sorbitol and other sugar alcohols are considered gluten free, too.

Physical symptoms, such as gas, bloating, cramping and loose stool, can occur from the ingestion of large amounts of sugar alcohols. However, these reactions do not have anything to do with gluten.

Spices are aromatic vegetable substances whose significant role is as a seasoning in food.

Some spices have been found to be contaminated with wheat, barley, or rye. Read Gluten Free Watchdog’s report on gluten contamination of spices (See link to the article below in References).

The single word “starch” in the ingredients list of FDA-regulated food product means cornstarch.

If an FDA-regulated product contains starch made from wheat, it will be listed as “wheat starch.” The manufacturer is allowed to label the product gluten free if the final product contains < 20ppm gluten. 

In USDA-regulated foods, the single word “starch” may mean cornstarch or wheat starch. If starch is listed, and the product does not have a gluten-free label, it may be best to contact the manufacturer to ask about the source of their starch. 

The single word “vinegar” in an ingredients list means “vinegar made from apples.” 

The following kinds of vinegars are gluten free: vinegar, cider vinegar, apple cider vinegar, wine vinegar, grape vinegar, distilled vinegar, white vinegar and balsamic vinegar.

Malt vinegar is NOT gluten free because it contains barley. Flavored vinegar also may contain malt as an ingredient.

Wheat starch is a finely processed powder derived from the endosperm (starchy portion) of the wheat plant.

It depends. Food containing wheat starch that is NOT labeled gluten free should not be eaten because it can contain high levels of gluten. A food labeled gluten free may contain wheat starch if the food contains <20 ppm of gluten. However, it is difficult to separate starch from protein in a grain of wheat and current testing is not perfect.

If a person with celiac disease chooses to eat wheat starch, Gluten-Free Watchdog recommends only choosing a product:

• IF it is labeled “gluten free.”
• IF the manufacturer and/or supplier test wheat starch for gluten using both the sandwich and competitive R5 ELISAs.

Whey is a protein found in milk.

Yes.

Yeast extract and autolyzed yeast extract are ingredients that may be made from spent brewer's yeast which is used in food as a flavoring agent. They can also be grown on sugar beets which are gluten-free.

It depends. Spent brewer’s yeast is a byproduct of the beer brewing process and, thus, can be contaminated with small amounts of gluten-containing grain and malt. An example of a product containing yeast extract from barley is Marmite, a British food spread. Per Gluten Free Watchdog, Marmite tested at ~30 parts per million which is not considered gluten free.

Per Gluten-Free Watchdog: It is not clear at this time how often spent yeast is the source of yeast extract in products sold in the US. Until we know more, it is best to avoid products NOT labeled gluten free containing the ingredient “yeast extract” [or autolyzed yeast extract] unless the source is confirmed to be gluten free by the manufacturer.

1. Thompson, T. Academy of Nutrition and Dietetics. Pocket Guide to Gluten-Free Strategies for Clients with Multiple Diet Restrictions. .Academy of Nutrition and Dietetics. . 2nd ed. Chicago, IL, 2016.

2. Gluten-free Dietitian. Blue Cheese. Accessed June 7, 2022.

3. Anca, A. Blue cheese in the gluten-free diet: a research update. Celiac News. 2009;23:1-5.

4. Thompson T, Dennis M, Emerson L. Gluten-free labeling: are growth media containing wheat, barley, and rye falling through the cracks? J Acad Nutr Diet. 2017 Sep 1.

5. Gluten-free Dietitian. Caramel Color. Accessed June 7, 2022.

6. US Food and Drug Administration. Code of Federal Regulations. Caramel. 21CFR73.85. Revised April 2017. Accessed July 24,2018.

7. Merriam Webster. Distilled Alcohol. Accessed June 7, 2022.

8. Gluten-free Dietitian. Maltodextrin. Accessed July 12, 2018.

9. Gluten-free Dietitian. Monosodium Glutamate. Accessed July 12, 2018.

10. Ault, Addison. The Monosodium Glutamate Story: The Commercial Production of MSG and Other Amino Acids. Journal of Chemical Education. 2004;81:347-355.

11. Sano, Chiaki. History of Glutamate Production. The American Journal of Clinical Nutrition. 2009;90:728S-732S. Available here.

12. Matheis, Gunter. Flavor Modifiers. In Philip R. Ashurst editor Food Flavorings. Gaithersburg, Maryland: Aspen Publishers. 1999:367-405.

13. Gluten-free Dietitian. Flavorings and Extracts: Are They Gluten Free? Accessed July 12, 2018

14. Gluten-free Dietitian. Barley Enzymes in Gluten-Free Products. Accessed July 12, 2018.

15. US Food and Drug Administration. Labeling of seasonings. Compliance Policy Guide. CPG Sec 525.650. October 1980.

16. Case, S. Gluten-Free: The Definitive Resource Guide. Case Nutrition Consulting. Saskatchewan, Canada, 2016.

17. US Food and Drug Administration. Code of Federal Regulations. Foods; labeling of spices, flavorings, colorings, and chemical preservatives. 21CFR101.22. Revised April 2009. Accessed July 23, 2018.

18. US Food and Drug Administration. Starches—common or usual names. Compliance Policy Guide. CPG Sec.578.100. October 1980. Accessed July 24, 2018.

19. Gluten-free Dietitian. Vinegar! Accessed July 12, 2018.

20. US Food and Drug Administration. Vinegar: definitions. Compliance Policy Guide. CPG Sec. 525.825. April 1977, rev. March 1995. Accessed June 7, 2022.

21. Gluten-Free Watchdog. May 8, 2017. Accessed June 7, 2022.

22. 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 here. Accessed July 23, 2018.

23. Gluten-Free Watchdog. Using wheat starch in gluten-free foods. April 2015. Accessed July 23, 2018.

24. Gluten Free Watchdog. Brewer’s Yeast and Gluten. May 29, 2018. Accessed July 12, 2018.

25. Gluten-Free Watchdog. Ingredient Information: Yeast Extract & Barley. May 17, 2017. Accessed June 7, 2022.

26. Gluten-Free Watchdog. Yeast extract and other words to look for in the ingredients list of foods NOT labeled gluten-free. May 16, 2017. Accessed July 12, 2018.

27. Food and Drug Administration (FDA). CFR - Code of Federal Regulations Title 2. Guar Gum. FDA Website. Updated January 6, 2022. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=184.1339

28. Food and Drug Administration (FDA). CFR - Code of Federal Regulations Title 2. Xanthan Gum. FDA Website. Updated January 6, 2022. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=172.695

Revision Date: August 23, 2022

Revised by Katarina Mollo, MEd, RDN, LDN

Revision Date: August 20, 2018

Revised by Melinda Dennis, MS, RDN

Editors: Amy Keller, MS, RDN, LD and Daniel Leffler, MD, MS

Original Date: 8-29-12

Author: Tricia Thompson, MS, RD

Editors: Melinda Dennis, MS, RD, LDN and Daniel Leffler, MD, MS