A rapid method to evaluate the chocolate smoothness based on the tribological measurement.

Cocoa is the primary ingredient in chocolate, and cocoa concentration attributes to the smoothness of the chocolate. Supporting this statement, we assessed the smoothness and melting properties of five chocolates of different cocoa concentration from three brands using the professional sensor evaluation and weight method, respectively. Artificial saliva was added to obtain the mixed chocolate solutions, and their viscosity and coefficient of friction (CoF) were measured for three rubbing pairs. The correlation of chocolate smoothness with their viscosities and average CoF (aCoF) was also discussed. The results indicated that the cocoa concentration significantly affected the smoothness of the chocolates among the three brands. The mixed solution of 50% chocolate could be a representative of oral processing, but their viscosities were not proficient enough to effectively characterize their smoothness. The aCoF of 50% chocolate solution could be rapid and effective to evaluate their smoothness. In addition, the Two-GCTPE rubbing pair was more suitable way to evaluate the smoothness of similar foods in the oral environment. The study results will provide a better insight into characterizing certain attribution of similar foods.