Histochemical identification of commercial wheat gluten

Abstract

Three methods for the microscopical identification of commercial wheat glutens are compared. A periodic acid-Schiff and an iodine-potassium iodide method both indicate gluten by showing the wheat starch present. Toluidine blue contained in an aqueous mountant distinguishes gluten protein from both soya and meat proteins. Each method identified commercial gluten present in a gluten-soya protein-meat mixture. Testing for both starch and protein is recommended for protein products that may contain added starch.