Titratable acidity of beverages influences salivary pH recovery

Abstract

A low pH and a high titratable acidity of juices andcola-based beverages are relevant factors that contribute to dentalerosion, but the relative importance of these properties to maintainsalivary pH at demineralizing levels for long periods of time afterdrinking is unknown. In this crossover study conducted in vivo,orange juice, a cola-based soft drink, and a 10% sucrose solution(negative control) were tested. These drinks differ in terms of theirpH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratableacidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH-to reach pH 5.5,respectively). Eight volunteers with a normal salivary flow rate andbuffering capacity kept 15 mL of each beverage in their mouth for 10 s,expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and120 s. The salivary pH, determined using a mini pH electrode, returnedto the baseline value at 30 s after expectoration of the cola-based softdrink, but only at 90 s after expectoration of the orange juice. The salivarypH increased to greater than 5.5 at 15 s after expectoration of the coladrink and at 30 s after expectoration of the orange juice. These findingssuggest that the titratable acidity of a beverage influences salivary pHvalues after drinking acidic beverages more than the beverage pH