Pumpkin puree in wood bowl with spoon on light surface
The '100% Pumpkin' Label On Canned Puree Isn't Actually True
Many brands of canned pumpkin purée label their products as "100% pure pumpkin," but this claim is murky, given the FDA's rather loose standards on what is considered "pumpkin".
In Compliance Policy Guide Sec 585.725, the FDA defines pumpkin products as "articles prepared from golden-fleshed, sweet squash or mixtures of such squash and field pumpkin."
"Golden-fleshed" and "sweet" apply to a large variety of squash, so a can of purée could contain little to no pumpkin and still be legally labeled as "100% pumpkin purée."
However, there's a good reason why most brands don't use pumpkin and only pumpkin in their products: common field pumpkins just don't make very good purée or food in general.
Common pumpkins are stringy, watery, and ill-suited for treats like pumpkin pie. Other squash create the buttery-smooth paste we're used to, so maybe a little less pumpkin is okay.