Thickness suitability of prebiotic dairy desserts: Relationship with rheological properties

In food product development it is important to know to what extent changes in formulation modifies the product, affecting its sensory properties and acceptability. Addition of polysaccharides like inulin can affect product structure in particular, modifying both rheological behaviour and perceived texture. The aim of this work was to assess to what extent rheological properties can explain the acceptability of thickness perceived by consumers in starch-based desserts. Low-fat dairy desserts were prepared varying the concentration of sucrose, flavor aroma and the fat replacer with prebiotic properties (inulin) but with fixed amounts of skimmed milk and starch. The rheological behavior was characterized and the level of sample thickness suitability was evaluated by a total of 100 consumers using a 5-point JAR scale (1 = too weak, 3 = just about right; 5 = too strong). Results indicated that flow and viscoelastic parameters varied among samples depending on inulin and sucrose concentration. According to sensory results, thickness suitability varied greatly between samples. The relationships between instrumental and sensory results are studied and discussed.