The Effect of Substituting Sugar With Isomalt, Inulin and Sorbitol on the Physical and Sensory Properties of Dark Chocolate

In recent years, there has been tendency among consumers to use low-calorie products with lower sugar content to promote their health. In this study, the effects of various bulk sweeteners such as isomalt, inulin and sorbitol in the formulation of dark chocolate as a sugar substitute on the rheological properties, melting behaviors and sensory properties of dark chocolate were compared and evaluated. The samples were subjected to steady and dynamic rheological analyses; melting parameters such as initial melting temperature, peak temperature, enthalpy and final melting temperature, as well as sensory analysis, were investigated using a 5-point hedonic method. The use of different types of bulk sweeteners had a significant effect on the rheological and sensory properties of dark chocolate; so, isomalt increased, while inulin and sorbitol decreased the apparent viscosity of the samples. Substituting sugar with sorbitol increased the gel-like behavior, while isomalt and inulin increased the viscous behavior of the samples. Bulk sweeteners also caused changes in the initial melting temperature and enthalpy, as well as decreasing the peak melting temperature of dark chocolate. Sensory evaluation also showed that the samples containing sorbitol had the lowest and those having sucrose had the highest score related to the total acceptance. Bulk sweeteners had different effects on the sensory and rheological properties of dark chocolate; so, the use of a mixture of these compounds to achieve an optimal formulation similar to that of the commercial sample is recommended.