Influence of dispersion media on the rheology and oral tribology of the konjac glucomannan/xanthan gum thickener.

Currently, thickeners are frequently added to foods to ensure safe diets for dysphagia patients. Konjac glucomannan (KGM) is a commonly used food thickener with health benefits as an excellent dietary fiber, but its rheological properties, such as no yield stress and poor gelling, prevent its direct use as a dysphagia thickener. This study exploited the potential of KGM as a dysphagia thickener through its synergistic interaction with xanthan gum (XG) and investigated the effects of dispersion media (water, juice, and soy milk) on the rheological properties and oral tribology of the KGM-XG thickener. The KGM-XG thickener (15:5 mass ratio of KGM to XG) was added to the dispersion media in an amount of 0.3–0.9% (w/w). The results showed the thickener had the strongest pseudoplasticity and apparent viscosity in water, exhibiting weak gel properties and yield behavior; whereas in juice and soy milk, apparent viscosity decreased due to the medium components interfering with KGM and XG synergistic interaction, and weak gel properties and yield behavior were only exhibited at higher levels (> 0.3%, w/w). The thickener had better ability to resist deformation and recovery in water than in juice and soy milk. The Stribeck curves effectively reflected the oral tribological behavior of the thickened systems, and the addition of the thickener reduced the friction coefficients of water and juice but had no significant effect on soy milk. Overall, KGM-XG is a promising thickener for dysphagia diets and offers a viable strategy for adding more dietary fiber to dietary formulations. [ABSTRACT FROM AUTHOR]