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Background and objectives: High sugar content is one of the major concerns in chocolate formulations. Although much research has been conducted aiming at replacing sugar with suitable replacres in milk chocolate, the results have not been very conclusive due to inducing undesirable texture and laxative effects. Therefore, in the present study we investigated the production of a low-energy milk chocolate with prebiotic properties using a Simplex Lattice Mixture Design. Materials and methods: Inulin as a prebiotic compound, with polydextrose, maltodextrin and a synthetic sweetener (sucralose), were used as sugar replacers in chocolate-making. Fifteen formulations were prepared using various ratios of these ingredients, and their effects on physicochemical, mechanical, rheological and sensory properties were determined. Results: In general, chocolates with high a level of sugar substitutes had a higher moisture content, viscosity and yield stress and a lower hardness than other samples and the controls. The lowest moisture content, viscosity and yield stress, as well as the highest hardness, were observed at the moderate levels of the ingredients. From among the 4 mathematical models used, Casson model showed the best fitting with our data and was employed for predicting rheological properties of the low-energy chocolates. The overall acceptance of the chocolate samples showed a direct relation with inulin and polydextrose and an inverse relation with maltodextrin. Based on the results of superimposed contour plots, the optimal values of inulin, polydextrose, and maltodextrin were 6.48–32.41% and 67.2–86.2%, 0–28.3% and 58.8–78.3%, and 0–30.6%, respectively. In addition, our data on fat reduction showed the possibility of fat reduction up to 5% and, consequently, a considerable energy cut (29%), in milk chocolates. Conclusions: Based on our findings, the Simlex Lattice Mixture Design is an appropriate method for finding optimal levels of inulin, polydextrose and maltodextrin in formulation of milk chocolate and producing a low energy–prebiotic milk chocolate very similar to ordinary chocolates.

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Background and Objective: Chocolate is one of the most popular food products, which, despite its desirable nutritional and health effects, can cause health risks/problems in consumers due to its high energy content. One way to reduce these risks/problems is to replace the sucrose with low-energy prebiotic compounds.The objective of the present study wasto explore the possibility of replacing sucrose with inulin, polydextrose, and maltodextrin in producing a low-energy dark chocolate with prebiotic properties using a Simplex Lattice Mixture Design. Materials and Methods: Sucralose (an artificial sweetener substituted for sucrose), was used along with inulin (a prebiotic), polydextrose and maltodextrin (bulking agents) with different ratios (0, 25, 50, 75 and 100%) to produce samples of a dark chocolate. The physicochemical (pH, water activity, and moisture, fat, and protein contents), mechanical and rheological (hardness, viscosity and yield value), as well as sensory (sweetness, firmness, mouth coating, and color) properties of the samples were examined. Results: The results showed that chocolate samples containing high levels of sugar substitutes had the highest moisture content and viscosity, as well as lower hardness. Out of the 5 mathematical models tested to predict the rheological characteristics of the chocolates produced, the Casson model was found to be the most suitable. There were no statistically significant differences between the treated and control samples as regards sensory characteristics. Furthermore, the results of superimposed contour plot showed optimum ranges to be 0–6% and 11–15% for inulin, 22–38% and 64–79% for polydextrose and 21–31% and 62–77% for maltodextrin. Conclusion: The findings show that a low-energy dark chocolate with prebiotic functional food properties can be produced using a low-energy sweetener (substituted for sucrose) and bulking agents (to improve rheological and sensory properties). Such a chocolate can compete with ordinary dark chocolate and can be consumed by children, adults and dieters with little restriction. Keywords: Dark chocolate, Inulin, Polydextrose, Maltodextrin, Rheology, Prebiotic