Impact of prebiotic fibre on the attributes of probiotic ice cream

Ice cream is a complex colloidal food system due to its components. Its complexity makes it an interesting vehicle for bioactive ingredients. In this study, we evaluated the effect of adding inulin (a prebiotic) to a probiotic vanilla-flavoured ice cream on quality parameters. Batches of ice cream were produced with a consistent concentration of the probiotic (Bifidobacterium, 10⁷ CFU) and inulin concentrations of 3%, 4%, and 6%. Several quality parameters were measured, including physicochemical (pH, total solids, acidity, and density), functional (time to first drip, melting percentage, and overrun), and microbiological (lactic acid bacteria count). These parameters were also sensorially evaluated. Overall, it was found that the concentration of probiotic bacteria is not susceptible to changes in inulin concentration nor to low storage temperatures. The different inulin concentrations did not generate significant changes in pH and acidity. On the contrary, the quality parameters were positively influenced, with a decrease in the melting percentage and first drip, as well as an increase in the percentage of total solids and overrun. In the sensory analysis, it was observed that at these levels of inulin addition, the sensory characteristics of the product remained unchanged.