I am trying to perfect a homade/DIY veggie burger recipe. I am trying to understand when, where and how (& the history of) the adjective "vital" came to be so routinely appended to wheat gluten as in "vital wheat gluten" or even less edifying as merely "vital gluten". I understand that one can make one's own wheat gluten by repeatedly rinsing whole wheat flour until all that remains is the protein wheat gluten ("seitan"/'wheat meat'). And by grinding that up one gets wheat gluten 'flour' (aka 'vital wheat gluten) But why use the adjective 'vital'. Apparently 'vital' is not necessarily capitalized & is not a proprietary term. So why is it used but seldom (never, in my experience) explained? I find it a very curious & puzzling situation indeed. Thank you.