It's no surprise that cakes, cookies, and all the other floury snacks contain gluten.
It is an important part of the manufacture, because the finished cement should be as fine and "floury" as possible.
In the common wheats the chaffscales are boat-shaped, ovoid, of the consistence of parchment, and shorter than the spikelet; the seed is usually floury, opaque, white, and easily broken.
In the turgid wheats the glumes have long awns, and the seed is turgid and floury, as in the common wheats.
As illustrating the fact of the occasional instability of these variations, Professor Church mentions that a single grain will be sometimes horny and partly opaque and floury, in which case its composition will correspond with its aspect.
The requirements of the consumer have also to be considered: for some purposes the soft floury wheats, with their large relative proportion of starch, are the best, for others the harder wheats, with their larger quantity of gluten.