Abstract:In order to estimate the effect of oral processing time on the frictional properties of typical foods rich in high sugar and fat,the factors affected on the frictional properties of chocolate in oral environment were investigated.Different mass percent solution of artificial saliva and chocolate brand were mixed.The ratio of base fluid and curing agent of the polydimethylsiloxane (PDMS) were varied to prepare the hard PDMS and soft PDMS with micropillars.Based on two rubbing pairs of ceramic ball vs soft PDMS and hard PDMS vs soft PDMS,the frictional properties of mixed solution was investigated under different loads and sliding speeds using the MFT5000 friction testing rig,and the interaction mechanism of mixed solution and rubbing pairs was discussed.The results show that the frictional properties of chocolate in the oral processing process are greatly related to mass percent of chocolate,load,sliding speed and rubbing pair.As the mass percent of chocolate is decreased,coefficient of friction is also reduced on the whole,indicating that consumers could obtain better silky sensation.The impact on frictional properties of chocolate from load and sliding speed is associated with the rubbing pairs,but the effect of load on the coefficient of friction is more significant than that of sliding speed.These results will provide a reference for frictional performance and mouthfeel evaluation of chocolate in the future.