Here's a pH test-- all olive oils are graded in accordance with the degree of this they contain (lower is better)
Both olive oil (OO)- and mineral oil-in-water emulsions better ... lower pH, more 
neutralized zeta potential, and increased affinity to .... and human low grade 5637 
(c) BC cells were treated with mycobacteria in OO ... the proliferation of all three 
BC cell lines to a similar degree to non-emulsified mycobacteria.