Impact of Dilution and Temperature on the Erosive Effect of Acidic Fountain Beverages

Objectives: The erosive potential of acidic beverages has been commonly attributed to their pH and titratable acidity, although other properties may also be relevant. In this study, we hypothesized that serving temperature and dilution rate impact the erosive potential of two popular fountain drinks: Coca-Cola and Gatorade.
Methods: They were tested at 10 different combinations of dilution in water: 100% (neat), 75%, 50% and 25%, and temperatures: 3 and 24° C, simulating the addition of different amounts of ice to the fountain beverages. Each group consisted of flattened and polished bovine enamel samples (n=8) exposed to the test beverage solutions for 10 min, twice a day, for a total of 3 days. In between beverage exposure and during the overnight period the specimens were kept immersed in artificial saliva. Knoop surface microhardness was measured (load of 50g, dwell time of 11s) on the polished surfaces before and after the experimental period. Percentage of enamel surface microhardness change was calculated. Means and standard-deviations are presented in the Table. Two-way ANOVA followed by Tukey test were performed, at 5% significance level.
Results: The interaction between beverage and test condition was non-significant (p>0.05). Capital letters denote significant difference between beverages; while small letters among test conditions. Overall, Gatorade showed higher erosive effect than Coca-Cola. Drinking the 100% (neat) beverages at cold temperature reduced the erosive potential significantly. Diluting the beverages did not reduce the erosive potential, except at the highest rate (25%), when no meaningful erosive effect was observed.
Conclusions: We concluded that cold and highly diluted fountain drinks present lower erosive potential.