Sensory perception of food is very important when it comes to consumer acceptance. The sensory impression in the oral cavity plays a key role. Especially the haptic properties are dominated by friction when the food is strained between the tongue and the palate. Tribology enables friction measurements by determining the coefficient of friction as the ratio between friction force and normal force. The aim of this study was to develop a method for tribological measurement of food within a simulated tongue-palate contact using varying surface combinations (tribopairs) in a rheometer set-up. The impact of surface handling and sampling procedures on the coefficient of friction was investigated in order to establish suitable conditions for the tribological characterisation of food samples with varying composition. Tribological measurements were carried out in a rheometer equipped with a tribology module. Additionally, the characterisation of the used counter and ground surfaces was conducted by AFM and SEM analyses. The reliability and reproducibility of the developed method is highly affected by the handling of the surfaces and the sampling of the foods, passing the run-in-period and the number of compressions between ground and counter surface. A tribopair consisting of a glass sphere on PDMS pins demonstrates the best usability with respect to low standard deviation, good reproducibility and distinct differentiation of all four sections of the Stribeck curve. The content of water in food systems has a substantial influence on these parameters, which is related to varying adhesive effects of the respective tribopair.
