Rheological and micro-structural properties of inulin prebiotic gels

Inulin is a non-digestible oligosaccharide that is present in many vegetables, fruits, and cereals. Nowadays, it is industrially extracted from chicory root and is widely used as an ingredient in functional foods (e.g. dairy products). In this research work, the rheological behavior of inulin gels was studied at different inulin (15, 20, 25 %) and calcium salts contents (lactate or chloride, at 0, 2.5 or 5 %). In general, an increase in the storage and viscous shear moduli (G' and G", respectively) was observed when increasing inulin content or when Calcium chloride was present in the original solution that led to the formation of the gel. On the other hand, both viscoelastic moduli generally decreased in the presence of Calcium lactate. The addition of Calcium chloride, therefore, allows the formation of a reinforced gel with the additional benefit of including Calcium in the formulation, which would be a good starting point for the production of functional foods.