Measurement of lubricating properties in a tribosystem with different surface roughness

Friction tests are indicated to be a tool for contributing to the description of creamy in-mouth sensations of a food product. As food labs are generally equipped with rheometers but not necessarily with tribometers, the use of a tribometer accessory that is attachable to a conventional rheometer is attractive. Therefore, lubricating properties of a tribology cell fixed to a rheometer as affected by synthetic elastic pads with different surface roughness and lubricating samples were examined. Surface morphology of used elastic pads was evaluated in terms of human tongue similarity. Lubricating performance of the tribosystem was strongly affected by the patterning of the elastic pad surface. Roughness indices were more crucial for lubricating properties in a tribosystem than stiffness parameters. Depending on the choice of elastic pad, different lubrication behaviour of yoghurt products was found which should be taken into account when correlating with sensory data.