How to apply ascorbic acid ppm in bread baking?
I did more googling of research papers and of all three sources accessible by me, ppm is actually per flour basis. Quite a shocker to me. 

Here are the links:ISSN No. (Print):0975-1130ISSN No. (Online):2249-3239TheEffect ofAscorbicAcid andGlycerol onQuality ofFrozen BarbariBread

Effects of Gliadin/Glutenin and HMW‐GS/LMW‐GS Ratio on Dough Rheological Properties and Bread‐Making Potential of Wheat Varieties

Method for producing danish dough 

I have also sent an email to Georgiana Gabriela Codina for good measure, though I am not sure if she responds to public queries.