Gum arabic and other polymers reduce citric acid erosion of enamel
What it found
In lab tests on human tooth enamel, citric acid solutions with gum arabic or propylene glycol alginate caused less softening than citric acid alone.
Pectin did not make a significant difference.
What they found
Animal and lab studies
Gum arabic and PGA
Enamel treated with citric acid plus gum arabic or propylene glycol alginate had significantly higher nanohardness than enamel treated with citric acid alone. This was found in lab tests on human tooth enamel.
Pectin
Adding highly esterified pectin to the citric acid did not significantly reduce the loss of enamel nanohardness compared with citric acid alone. This was in lab tests on human tooth enamel.
Surface smoothness
Enamel eroded with the polymer-modified citric acid solutions generally had a smoother surface than enamel treated with citric acid alone, based on scanning electron microscopy images.
Possible protective layer
The authors suggest the polymers may stick to the eroded enamel surface and form a protective layer. For gum arabic and propylene glycol alginate, this possible layer reduced the erosive effects of the citric acid solutions.
What the authors conclude
“The present in vitro erosion study shows that some of the polymers used in this study may possibly adsorb like a protective layer directly onto the human enamel surface.”
Also in their conclusions
- They conclude that some of the polymers used in this lab study may possibly adsorb like a protective layer directly onto the human enamel surface.
- They state that for gum arabic and propylene glycol alginate this possibly formed polymer layer reduces the erosive effects of citric acid solutions, as shown by nanoindentation measurements.
How it was done
Drinking acidic soft drinks can dissolve and soften human tooth enamel, a process called erosion. The authors wanted to see whether adding certain polymers to citric acid could reduce that erosion.
They embedded pieces of non-erupted human third molars in resin, then ground and polished them to make enamel samples. The samples were exposed for 30, 60 or 120 seconds to citric acid solutions at pH 2.3, 3.3 or 4.0, either alone or with 1% of one polymer: highly esterified pectin, propylene glycol alginate or gum arabic. They then measured the enamel's nanohardness and elastic modulus and imaged the surface.
What it can’t tell you
- We summarised it from the abstract only.
- This was a lab study on extracted human tooth enamel, not on people. It cannot show what happens to teeth inside the mouth, where saliva and other factors are present.
- The study only looked at short exposure times of 30, 60 and 120 seconds and did not test long-term or repeated exposure.
Who paid
- Authors work at
- Friedrich-Schiller-University Jena, Germany
The paper
- Title
- Pectin, alginate and gum arabic polymers reduce citric acid erosion effects on human enamel
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Beyer M, Reichert J, Heurich E, Jandt KD, Sigusch BW (2010). Pectin, alginate and gum arabic polymers reduce citric acid erosion effects on human enamel. Dental materials. doi:10.1016/j.dental.2010.04.008PubMed 20569976DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error