The effects of Stevia (Rebaudioside) and Inulin on the Physicochemical, Antioxidant and Sensory Properties of Low-Calorie Chocolate Dairy Dessert

Since carbohydrates and fats are known to be the most important calorie sources in food products, much attention has been focused on low calorie or non-caloric substitutes. The main purpose of this research is to produce low calorie chocolate dairy desssert with functional characteristics, while reducing the calorie content, in most cases, competitive with a variety of commercial food products and not being too restrictive for children, adults and others. In this research, stevia was used as a sugar substitute and inulin as a fat substitute in the low calorie chocolate dessert formula, and the best formulation was obtained The purpose of this research is to produce dietary products for people with diseases such as obesity, cardiovascular disease, blood pressure, insulin-free diabetes and etc.

In this study, stevia and inulin was used as sugar and fat replacer in chocolate dairy dessert formulation, respectively. In order to optimize the formula and produce low-calorie chocolate dairy dessert, three factors of inulin concentration (0 to 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 Composit. The physicochemical characteristics including fat and protein content, dry matter content, calorific value, antioxidant activity, color and sensory properties were analyzed in the chocolate dairy dessert. The antioxidant effects of Stevia in dairy desserts was investigated using iron reducing power test and DPPH radical scavenging activity. The samples were evaluated for appearance, consistency, odor, and taste using a 9-point hedonic method.

The results showed that the energy values of the chocolate dairy dessert samples decreased significantly with reducing fat level. DPPH free radical scavenging and reducing power assays in chocolate dairy desserts showed that samples with higher amounts of Stevia extract had higher antioxidant activities. In addition, dairy desserts containing Stevia extract showed high levels of free radical scavenging activities during two weeks’ storage that may result in delay in fat oxidation and increase shelf life of the stevia containing food product. The L* values was negatively affected by the inulin addition. No significant differences in the a* and b* values were detected between the different samples. Overall acceptability decreased by increasing inulin levels to more than 4% and stevia levels to more than 0.03%.

According to the obtained model, the formulation was selected with 5.628 g/100 g inulin, 0.032 g/100 g stevia and 5.83 g/100 g as the best model.