Effects of inulin and bulking agents on rheological properties and particle size distribution of low calorie dark chocolate

Molten dark chocolate is a dispersion of solid particles including sugar and cocoa powder in a continuous phase of cocoa butter. Hence, the rheological properties as well as the particle size distribution of ingredients in chocolate are very important for obtaining high-quality products with well-defined texture. Therefore, the present study aimed to evaluate the effects of sugar substitutes on rheological characteristics and particle size distribution of prebiotic dark chocolate. For doing this, a prebiotic compound (inulin) in combination with bulking agents (polydextrose and maltodextrin) at different levels (0–100 %) along with sucralose were used. Based on our findings, all the treateded samples showed thixotropic and pseudoplastic behavior and the Casson mathematical model most closely fitted to the rheological data. Furthermore, the sucrose replacement slightly affected the viscoelastic properties and the viscosity of the samples was time independent. In terms of the particle size, they were somewhat larger than the commercial one but still below the taste threshold.