Test your salivary and urinary pH levels at home with these convenient test strips.
How It Works
PH paper is treated with a chemical indicator that changes in the presence of hydroxide or hydrogen ions. Such chemical indicators can be found in foods such as red cabbage, strawberries or blueberries, to name a few, according to professors at Purdue University.
Why the Color Change
This pH paper changes color in different pH solutions because of the chemical flavin, which is a pigment present in red cabbage. This molecule, which is an anthocyanin (see Resources), is soluble in water and changes color in the presence of various types of solutions. In the presence of an acidic solution, it turns red. In the presence of a basic solution, it turns greenish. In the presence of a neutral solution, it turns purple, as indicated by adminsitrator L. Bry at MadSci Research.
Reference: Sciencing.com