Brian D. Guthrie

Normal force-controlled tribological measurement of soft drinks and lubrication additives

This paper describes the use of a normal force-controlled tribology device for assessing mouthfeel-related lubrication properties of soft drinks samples and lubrication additives. Samples were sheared between a tribology pair comprised of steel and thermoplastic elastomer surfaces with the 3-contact ball-on-inclined plane tribometer. The boundary lubrication of lemon lime soft drinks was significantly lower than cola soft drinks. The resolution of the instrument was further investigated by measuring the lubrication of confined very dilute non gelling neutral and strongly charged β-1,4 polysaccharides. Poor lubrication was seen with the galactomannans locust bean gum and guar gum. Overall, these experiments demonstrate that tribology yields reproducible results that relate to functional properties of iso-viscous fluids in a dilute regime.