Under the Food Labeling and Consumer Protection Act (FALCPA), if an FDA-regulated food product contains maltodextrin and the maltodextrin contains protein derived from wheat, the word “wheat” must be included on the food label (e.g., maltodextrin (wheat)). If you don’t see the word wheat on an FDA-regulated product containing maltodextrin, the food product does not contain any wheat protein.
However, for USDA-regulated foods, only the common or usual name is required to be listed on the food label. Therefore, maltodextrin may simply be labeled as “maltodextrin” even if it contains protein derived from wheat. USDA-regulated foods include meat products, poultry products, and egg products. Depending upon the percentage of meat or poultry in a product this can include foods such as soups.
From: http://www.glutenfreedietitian.com/newsletter/maltodextrin/ January, 2013