Concentration depends on what you eat, and iirc you don't need that much protein anyways, if you aren't training/body building.
Tofu has about half the amount of protein per gram then ground beef, tempeh about 85%.
If you really crave protein tvp has between 50 and 70% per gram (absolute, not relative to ground beef) protein depending on the brand. You still need to hydrate it and cook it properly with a good marinade, but then it can pretty easily beat ground beef or even chicken breast in protein by weight.
