Dextrin, a common additive that’s made by heating starch, can come from corn, potato, arrowroot, wheat, rice or tapioca.
If either of these additives is an ingredient and you are not sure the product is gluten-free, the safest thing to do is call the manufacturer and ask them to tell you the source of the maltodextrin or dextrin.
The Sugar Association, Inc. Accessed: February 15, 2009. http://www.sugar.org/consumers/sweet_by_nature.asp?id=277
GrokFood Online Food Additives Database: U.S. Code of Federal Regulations. Accessed: February 15, 2009. For maltodextrin: http://www.grokfood.com/regulations/184.1444.htm. For dextrin: http://www.grokfood.com/regulations/184.1277.htm