Inulin blend as prebiotic and fat replacer in dairy desserts: Optimization by response surface methodology

The purpose of this work was to optimize the formulation of a prebiotic dairy dessert with low fat content (<0.1. g/100. g) using a mixture of short- and long-chain inulin. Response surface methodology was applied to obtain the experimental design and data analysis. Nineteen formulations of dairy dessert were prepared, varying inulin concentration (3 to 9. g/100. g), sucrose concentration (4 to 16. g/100. g), and lemon flavor concentration (25 to 225. mg/kg). Sample acceptability evaluated by 100 consumers varied mainly in terms of inulin and sucrose concentrations and, to a lesser extent, of lemon flavor content. An interaction effect among inulin and sucrose concentration was also found. According to the model obtained, the formulation with 5.5. g/100. g inulin, 10. g/100. g sucrose and 60. mg/kg of lemon flavor was selected. Finally, this sample was compared sensorially with the regular fat content (2.8. g/100. g) sample previously optimized in terms of lemon flavor (146. mg/kg) and sucrose (11.4. g/100. g). No significant difference in acceptability was found between them but the low-fat sample with inulin possessed stronger lemon flavor and greater thickness and creaminess.