Example 4
The impact of calcium carbonate on saliva pH and buffer capacity was measured from saliva collected before and after consumption of a tablet containing 112 mg (7%) of calcium carbonate. Five subjects were asked to chew the tablet for 10 seconds, swish the generated liquid for 40 seconds and then swallow. Saliva was collected for five minutes prior to tablet use, and for five minutes immediately following.
The collected saliva was homogenized by vortexing for 20 seconds and the pH measured using a pH electrode. The buffer capacity, defined as the mM of HCl required to drop the pH by one unit, was determined by acid titration. 0.1 M HCl was added 20-40 uL at a time to 0.5 mL of saliva, and the pH measured after each addition until the pH dropped below pH=5. The buffer capacity was calculated from the slope of the linear regression of mM of HCl added over the change in pH.
