Noni fruit juice and leaves are alkaline foods.

J Med Food Plants 1(2):53-54. 2009. 
Noni fruit juice and leaves are alkaline foods.
West BJ.

The potential impacts of noni juice and leaves on the body’s acid/alkaline balance were determined by measuring the pH of ash residues and by mineral analysis. The analyses demonstrate that both noni juice and noni leaves are alkaline-forming foods and will not have an adverse effect on the acid/alkaline balance of the body. (available online at https://sites.google.com/a/jmedfoodplants.com/www/vol-1-1-jul-dec-2009).