Acid Production from a Nonsugar Licorice and Different Sugar Substitutes in Streptococcus mutans Monoculture and Pooled Plaque-Saliva Mixtures

Abstract

Acid production from an experimental, nonsugar licorice, its separate constituents and some other foodstuffs was measured in bacterial suspensions. A strain of Streptococcus mutans and a fresh, pooled plaque-saliva mixture were used to test the fermentability of the substrates. The experimental licorice proved to be relatively well fermentable by both S. mutans and the plaque-saliva mixture. Of its ingredients the polysaccharides showed to be most acidogenic, gum arabic, xylitol and a protein derivative producing very little acid. Sorbitol showed a slight acid production in the plaque-saliva medium. In this medium, hydrogenated potato starch exhibited a relatively high degradability. S. mutans precultured on sorbitol and hydrogenated potato starch showed a considerably reduced capacity to ferment glucose. Telemetry of interdental plaque pH showed a critical drop after consumption of the experimental licorice, i. e. to pH 5.