The effects of Stevia (Rebaudioside) and Inulin on the Chemical and Microbial Properties of Low-Calorie Chocolate Dairy Dessert

Carbohydrates and lipids are known as the most important sources of calorie intake in food products, much attention has been paid to low-calorie and non-caloric alternatives. In this research, stevia and inulin was used as sugar and fat replacer in chocolate dairy dessert formulation, respectively. Inorder to optimize the formula and low-calorie chocolate dairy dessert production, three factors of inulin concentration (0to 8 g/100 g), stevia concentration (0 to 0.06 g/100 g), and storage day (1 to 14 day) were evaluated using response surface methodology (RSM) with Face-Centered Central Composite. Then, the chemical characteristics including pH, acidity, fat and protein content, and microbial properties were analyzed in the chocolate dairy dessert after 1, 4, 7, 10 and 14 days’ storage. Folch method applied for fatty acids extraction and Gas Chromatography used for determination of fatty acids. The results showed that the pH value decreased with increase in inulin content. An increase in unsaturated fatty acids was observed in low calorie chocolate dairy dessert. The Highest percentage of fatty acids in chocolate dairy dessets were palmitic acid followed by oleic acid. The evaluation of Sucrose, Lactose and Glucose content with HPLC Technique showed that sucrose was the dominate sugar in the control sample but lactose had more content in low calorie desserts. Both total bacterial count and mold and yeast count, were lower than the standard range. According to the model obtained, the formulation with 5.628 g/100 g inulin, 0.032 g/100 g stevia and 5.83 g/100 g of sucrose was selected.