An in vitro system to compare erosive potential of beverages

Methods: Hydroxyapatite discs, sintered at 1250 ºC and having a relative density of 98%, were exposed in vitro for four hours at 37 ºC to Red Bull, Sprite Zero, Coca Cola, Orange juice, Isostar Orange, Mona Puur drink or Apfel Schorle. 1% Citric Acid and PBS were used as positive and negative controls, respectively. The erosive potential was quantified by determing (I) weight loss of hydroxyapatite discs, (II) depth of erosive lesion in profilometric measurements and (III) change in Knoop surface microhardness. Data were analysed with ANOVA, followed by Tukey-HSD.

Results: Weight loss was increased after incubation in 1% Citric Acid, Sprite Zero, Coca Cola, Apfel Schorle, Red Bull and Orange juice. The mean depth of erosive lesions was significantly increased after exposure to 1% Citric Acid, Sprite Zero, Coca cola, Orange juice and Apfel Schorle. 1% Citric Acid, Sprite Zero, Coca Cola and Orange juice also induced significant reductions in surface microhardness, whereas for Apfel Schorle the reduction in surface microhardness almost reached statistical significance (p<0.095). Isostar Orange and Mona Puur had no effect on each parameter.

Conclusion: Hydroxyapatite discs can be used to compare the erosive potential of drinks in vitro. For each parameter, Sprite Zero, Coca Cola and Orange juice showed a significant erosive potential.

This study was financially supported by FrieslandCampina Innovation Europe.